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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.ahj.2010.06.005 Byline: John D. Eicher (a), Carl M. Maresh (a), Gregory J. Tsongalis (b), Paul D. Thompson (c), Linda S. Pescatello (a) Abbreviations: ABP, ambulatory blood pressure; HTN, hypertension; BP, blood pressure; CVD, cardiovascular disease; Vo.sub.2peak, peak oxygen consumption; PEH, post-exercise hypotension; SBP, systolic blood pressure; DBP, diastolic blood pressure; HR, heart rate; CRP, C-reactive protein; FIB, fibrinogen; CV, coefficient of variation; LDL, low density lipoprotein Abstract: Evidence contends lower levels of physical exertion reduce blood pressure (BP) as effectively as more rigorous levels. We compared the effects of low (40% peak oxygen consumption, Vo.sub.2peak), moderate (60% Vo.sub.2peak), and vigorous (100% Vo.sub.2peak) exercise intensity on the BP response immediately following aerobic exercise. We also examined clinical correlates of the BP response. Author Affiliation: (a) University of Connecticut, Storrs, CT (b) Dartmouth-Hitchcock Medical Center, Lebanon, NH (c) Hartford Hospital, Hartford, CT Article History: Received 20 January 2010; Accepted 2 June 2010 Article Note: (footnote) Sources of Support: Supported by American Heart Association Grant-in-Aid #0150507N.

Objectives: Determine whether five days of heat acclimation reduces cardiovascular and thermoregulatory strain during consecutive exercise-heat exposures on the sixth day in the heat.Design: Pair-matched randomized control trial.Methods: Twenty-four males completed two, 120min exercise sessions (Session 1, Session 2) in a single day before (Day 1) and after (Day 6) four additional days of exercise in either hot (HOT: 40°C, 40% relative humidity, n=16) or temperate (CON: 23°C, 25% relative humidity, n=8) environments. A mixed-methods heat acclimation approach was implemented. Day 2 consisted of 120min of moderate-high intensity treadmill exercise. Days 3-5 consisted of 90min of moderate-high intensity exercise, with HOT completing this in a hyperthermia clamped manner at rectal temperature ≥38.5°C, and CON<38.5°C.Results: Session 1 end of exercise rectal temperature and heart rate were lower on Day 6 compared to Day 1 for HOT (p=0.012, p=0.003) but not CON (p=0.152, p=0.437). Session 2 end of exercise rectal temperature was not different between days for HOT (p=0.104) or CON (p=0.275). Session 2 end of exercise heart rate was lower on Day 6 compared to Day 1 for HOT (p=0.004) and CON (p=0.039). Session 1 sweat sensitivity was greater on Day 6 compared to Day 1 for HOT (p=0.039) but not CON (p=0.257). Sweat rate was unchanged for HOT and CON between days during Session 1 (p=0.184, p=0.962) and Session 2 (p=0.051, p=0.793), respectively.Conclusions: Five days of heat acclimation reduced cardiovascular strain but not thermoregulatory strain during the second, consecutive exercise-heat exposure. CLINICALTRIALS.Gov Identifier: NCT04053465. [ABSTRACT FROM AUTHOR]

Objectives: An exercise session in a hot environment may increase thermal strain during subsequent exercise sessions on the same and consecutive days. Therefore, this study was conducted to determine lasting physiological strain from moderate-high intensity, intermittent exercise in heat on subsequent exercise.Design: Repeated measures laboratory study.Methods: Seventeen healthy, recreationally active men (age: 22±3 y, maximal oxygen consumption: 54.6±5.3mLkg-1min-1) underwent two intermittent moderate-high intensity aerobic exercise sessions separated by 2h of rest one day, followed by one session 24h later in a 40°C, 40% relative humidity environment. Heart rate, rectal temperature, heat stress perception, and environmental symptoms were assessed.Results: 100%, 35%, and 71% of participants completed the full exercise protocol during the first exercise session, second exercise session, and the following day, respectively. Exercising heart rate and rectal temperature were greater during the second exercise session (189±11bpm, 38.80±0.47°C) than the first identical exercise session (180±17bpm, p=0.004; 38.41±0.52°C, p=0.001), respectively. Immediate post-exercise heart rate, rectal temperature, thirst, thermal sensation, fatigue, and perceived exertion were similar among exercise sessions despite a shorter exercise duration during the second exercise session (93±27min, p=0.001) and the following day (113±12min, p=0.032) than the first exercise session (120±0min).Conclusions: Moderate-high-intensity intermittent exercise in the heat resulted in greater heat strain during a second exercise session the same day, and exercise the subsequent day. [ABSTRACT FROM AUTHOR]

Objectives: To determine if intermittent exercise-heat exposures (IHE) every fifth day sustain heat acclimation (HA) adaptations 25 days after initial HA.Design: Randomized control trial.Methods: Sixteen non-heat acclimatized men heat acclimated during 10-11 days of exercise in the heat (40°C, 40% RH). A heat stress test (120min, 45% V˙O2peak) before (Pre HA) and after HA (Post HA) in similar hot conditions assessed HA status. Pair-matched participants were randomized into a control group (CON; n=7) that exercised in a temperate environment (24°C, 21%RH) or IHE group (n=9) that exercised in a hot environment (40°C, 40%RH) every fifth day for 25 days following HA (+25d) with out-of-laboratory exercise intensity and duration recorded. Both groups completed +25d in the hot condition.Results: Both groups heat acclimated similarly (p>0.05) evidenced by lower heart rate (HR), thermoregulatory, physiological, and perceptual responses (perceived exertion, fatigue, thermal sensation) Pre HA vs. Post HA (p≤0.05). At +25d, post-exercise HR (p=0.01) and physiological strain index (p<0.05) but neither Tre (p=0.18) nor sweat rate (p=0.44) were lower in IHE vs. CON. In IHE only, post-exercise Tre and perceptual responses at Post HA and +25d were lower than Pre HA (p≤0.01). +25d post-exercise epinephrine was higher in CON vs. IHE (p=0.04). Exercise intensity during out-of-lab exercise and +25d post-exercise HR were correlated (r=-0.89, p=0.02) in IHE.Conclusions: Exercise-heat exposures every fifth day for 25 days and regular intense physical activity after HA sustained HR and Tre adaptations and reduced perceptual and physiological strain during exercise-heat stress ∼1 month later. [ABSTRACT FROM AUTHOR]

Objectives: Cold water immersion (CWI) has been widely used for enhancing athlete recovery though its use following an Ironman triathlon has never been examined. The purpose of this paper is to determine the influence of CWI immediately following an Ironman triathlon on markers of muscle damage, inflammation and muscle soreness.Design: Prospective cohort study.Methods: Thirty three (22 male, 11 female), triathletes participating in the Ironman World Championships volunteered to participate (mean±SD: age=40±11years; height=174.5±9.1cm; body mass=70±11.8kg; percent body fat=11.4±4.1%, finish time=11:03.00±01:25.08). Post race, participants were randomly assigned to a 10-min bout of 10°C CWI or no-intervention control group. Data collection occurred pre-intervention (PRE), post-intervention (POST), 16h (16POST) and 40h (40POST) following the race. Linear mixed model ANOVA with Bonferroni corrections were performed to examine group by time differences for delayed onset muscle soreness (DOMS), hydration indices, myoglobin, creatine kinase (CK), cortisol, C-reactive protein (CRP), IL-6 and percent body mass loss (%BML). Pearson's bivariate correlations were used for comparisons with finishing time. Alpha level was set a priori at 0.05.Results: No significant group by time interactions occurred. Significant differences occurred for POST BML (-1.7±0.9kg) vs. 16POST, and 40POST BML (0.9±1.4, -0.1±1.2kg, respectively; p<0.001). Compared to PRE, myoglobin, CRP and CK remained significantly elevated at 40POST. Cortisol returned to PRE values by 16POST and IL-6 returned to PRE values by 40POST.Conclusion: A single bout of CWI did not provide any physiological benefit during recovery from a triathlon within 40h post race. Effect of CWI beyond this time is unknown. [ABSTRACT FROM AUTHOR]

Background Many successful ultra-endurance athletes have switched from a high-carbohydrate to a low-carbohydrate diet, but they have not previously been studied to determine the extent of metabolic adaptations. Methods Twenty elite ultra-marathoners and ironman distance triathletes performed a maximal graded exercise test and a 180 min submaximal run at 64% VO 2 max on a treadmill to determine metabolic responses. One group habitually consumed a traditional high-carbohydrate (HC: n = 10 , %carbohydrate:protein:fat = 59:14:25) diet, and the other a low-carbohydrate (LC; n = 10 , 10:19:70) diet for an average of 20 months (range 9 to 36 months). Results Peak fat oxidation was 2.3-fold higher in the LC group (1.54 ± 0.18 vs 0.67 ± 0.14 g/min; P = 0.000 ) and it occurred at a higher percentage of VO 2 max (70.3 ± 6.3 vs 54.9 ± 7.8%; P = 0.000 ). Mean fat oxidation during submaximal exercise was 59% higher in the LC group (1.21 ± 0.02 vs 0.76 ± 0.11 g/min; P = 0.000 ) corresponding to a greater relative contribution of fat (88 ± 2 vs 56 ± 8%; P = 0.000 ). Despite these marked differences in fuel use between LC and HC athletes, there were no significant differences in resting muscle glycogen and the level of depletion after 180 min of running (− 64% from pre-exercise) and 120 min of recovery (− 36% from pre-exercise). Conclusion Compared to highly trained ultra-endurance athletes consuming an HC diet, long-term keto-adaptation results in extraordinarily high rates of fat oxidation, whereas muscle glycogen utilization and repletion patterns during and after a 3 hour run are similar. [ABSTRACT FROM AUTHOR]

Objectives Determine if performance and physiological based pacing characteristics over the varied terrain of a triathlon predicted relative bike, run, and/or overall success. Poor self-regulation of intensity during long distance (Full Iron) triathlon can manifest in adverse discontinuities in performance. Design Observational study of a random sample of Ironman World Championship athletes. High performing and low performing groups were established upon race completion. Methods Participants wore global positioning system and heart rate enabled watches during the race. Percentage difference from pre-race disclosed goal pace (%off) and mean HR were calculated for nine segments of the bike and 11 segments of the run. Normalized graded running pace (accounting for changes in elevation) was computed via analysis software. Step-wise regression analyses identified segments predictive of relative success and HP and LP were compared at these segments to confirm importance. Results %Off of goal velocity during two downhill segments of the bike (HP: −6.8 ± 3.2%, −14.2 ± 2.6% versus LP: −1.2 ± 4.2%, −5.1 ± 11.5%; p < 0.020) and %off from NGP during one downhill segment of the run (HP: 4.8 ± 5.2% versus LP: 33.3 ± 38.7%; p = 0.033) significantly predicted relative performance. Also, HP displayed more consistency in mean HR (141 ± 12 to 138 ± 11 bpm) compared to LP (139 ± 17 to 131 ± 16 bpm; p = 0.019) over the climb and descent from the turn-around point during the bike component. Conclusions Athletes who maintained faster relative speeds on downhill segments, and who had smaller changes in HR between consecutive up and downhill segments were more successful relative to their goal times. [ABSTRACT FROM AUTHOR]

Abstract: Resistance exercise (RE) is increasingly recommended by health organizations as a weight management tool. The purpose of this study was to examine the effects of an acute high-volume, whole-body RE protocol on the glucoregulatory and ghrelin response in sedentary obese and lean men. Five World Health Organization (WHO) class 1 obese (body mass index [BMI], 30.00-34.99) (age, 21.6 ± 2.5 years; height, 176.3 ± 3.7 cm; body mass, 97.8 ± 8.58 kg; body fat, 34.7% ± 2.95%), 5 WHO 2 (BMI, 35-39.99)/WHO 3 (BMI, ≥40) obese (age, 20.0 ± 1.4 years; height, 177.7 ± 5.15 cm; body mass, 120.8 ± 10.49 kg; body fat, 40.5% ± 5.82 %), and 9 lean men (age, 20.1 ± 2.1 years; height, 177.8 ± 8.7 cm; body mass, 71.7 ± 5.8 kg; body fat, 14.7% ± 3.54 %) completed an acute RE testing protocol (6 exercises, 3 sets of 10 repetitions at 85%-95% 10-repetition maximum with 120- and 90-second rest periods); and blood samples were collected pre-, mid-, and immediately postexercise and during recovery (+50, +70, and +110). Resistance exercise produced differences over time in cortisol, insulin, and glucose. Group differences were observed for ghrelin, with the WHO class 2/3 group having significantly greater ghrelin levels than the lean group (d = 0.28, P = .009) and the WHO class 1 group (d = 0.39, P = .002). Higher ghrelin was significantly associated with lower cortisol only in obese individuals. In addition, higher growth hormone was associated with lower ghrelin in lean individuals. Results suggest that glucoregulatory homeostasis is altered with increasing levels of obesity and that these alterations may mediate the response of cortisol and ghrelin in response to RE. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to examine the effects of Carnipure tartrate (Lonza, Allendale, NJ) supplementation (total dose of 2 g/d of l-carnitine) on markers of performance and recovery from physical exertion in middle-aged men and women. Normally active and healthy men (n = 9, 45.4 ± 5.3 years old) and women (n = 9, 51.9 ± 5.0 years old) volunteered to participate in the investigation. Double-blind, placebo, balanced treatment presentation and crossover design were used with 3 weeks and 3 days of supplementation followed by a 1-week washout period before the other counterbalanced treatment was initiated. After 3 weeks of each supplementation protocol, each participant then performed an acute resistance exercise challenge of 4 sets of 15 repetitions of squat/leg press at 50% 1-repetition maximum and continued supplementation over the recovery period that was evaluated. Blood samples were obtained at preexercise and at 0, 15, 30, and 120 minutes postexercise during the acute resistance exercise challenge and during 4 recovery days as well. Two grams of l-carnitine supplementation had positive effects and significantly (P ≤ .05) attenuated biochemical markers of purine metabolism (ie, hypoxanthine, xanthine oxidase), free radical formation (malondialdehyde), muscle tissue disruption (myoglobin, creatine kinase), and muscle soreness after physical exertion. However, markers of physical performance (ie, strength, power, get up and go) were not affected by supplementation. These findings support our previous findings of l-carnitine in younger people that such supplementation can reduce chemical damage to tissues after exercise and optimize the processes of muscle tissue repair and remodeling. [Copyright &y& Elsevier]

Abstract: The purpose was to examine effects of oral contraceptive (OC) use on plasma growth hormone (GH) responses to heavy resistance exercise. Sixty untrained women were placed into one of two groups: currently using OC (Ortho Tri-Cyclen®) (n =25; mean±SD: 24.5±4.2y, 160.4±7.1cm, 64.1±11.3kg) or not currently using OC (NOC) (n =35; 23.6±4.6y, 165.9±6.0cm, 65.7±10.3kg). Participants performed an acute heavy resistance exercise test (AHRET; six sets of 10 repetition squats; 2min rest between sets) during days 2–4 of the follicular phase (NOC group) or of inactive oral contraceptive intake (OC group). Plasma was obtained before and immediately after AHRET and subsequently fractionated based on apparent molecular weight (>60kD, 30–60kD, and <30kD). GH was determined in unfractionated plasma and each plasma fraction using 4 methods: (1) Nichols Institute Diagnostics immunoradiometric assay (Nichols), (2) National Institute of Diabetes and Digestive Kidney Diseases (NIDDK) competitive radioimmunoassay, (3) DSL immunofunctional enzyme-linked immunoabsorbent assay (IFA) and (4) rat tibial line bioassay. GH increased (P <0.05) in all fractions post-AHRET for the Nichols, NIDDK, and IFA. The OC group displayed higher resting GH for the NIDDK, and higher exercise-induced GH for the IFA, Nichols, and NIDDK in unfractionated plasma and >60kD subfraction compared to NOC group. No differences were observed for the tibial line bioassay. OC use augmented immunological GH response to AHRET in unfractionated plasma and >60kD molecular weight subfraction. However, OC use only increased biological activity of GH in one of two bioassays. These data demonstrated that GH concentrations at rest and following exercise are assay-dependent. [Copyright &y& Elsevier]

Abstract: The aim of this study was to examine the effect of adding a total-body exercise program to an 8-week diet supplemented with glucomannan on weight loss, body composition, blood parameters, and physical performance in overweight men and women. Sedentary men and women who were overweight (body mass index >25 kg m−2) (men: 18-57 years, 27.0 ± 11.2 years, 177.5 ± 7.6 cm, 102.4 ± 14.9 kg; women: 18-52 years, 33.4 ± 12.1 years, 160.6 ± 4.6 cm, 79.9 ± 9.3 kg) completed an 8-week diet with 3000 mg glucomannan combined with either no exercise (No-Ex) (10 men, 10 women) or a resistance and endurance exercise training program (Ex) (12 men, 10 women). The diet emphasized healthy food choices and portion size control. The exercise training consisted of 3 weekly sessions of approximately 1 hour of a nonlinear periodized total-body resistance exercise program followed by 30 minutes of endurance exercise. After the intervention, there were reductions (P < .05) in body mass (men, −2.7 ± 1.4 and −3.0 ± 4.0 kg; women, −2.2 ± 1.5 and −3.3 ± 1.5 kg; No-Ex and Ex, respectively), fat mass (men, −2.3 ± 1.6 and −3.9 ± 2.5 kg; women, −2.6 ± 1.4 and −3.6 ± 1.1 kg; No-Ex and Ex, respectively), total cholesterol (TC) (men, −17.9 ± 21.5 and −18.8 ± 19.4 mg dL−1; women, −9.3 ± 20.0 and −10.1 ± 19.5 mg dL−1; No-Ex and Ex, respectively), and low-density lipoprotein cholesterol. Exercise significantly improved high-density lipoprotein cholesterol (HDL-C) (No-Ex, −2.0 ± 4.7 and −2.3 ± 4.5 mg dL−1 vs Ex, 4.4 ± 10.8 and 1.6 ± 3.6 mg dL−1; men and women, respectively), TC/HDL-C ratio, squat and bench press 1-repetition maximum, and distance covered during a shuttle-run test. In addition, exercise appeared to augment the reduction in fat mass (by 63% and 50%; men and women, respectively) and waist circumference, but did not affect total weight loss. Addition of a resistance and endurance exercise training program to a glucomannan diet regimen significantly improved measures of body composition, HDL-C, and TC/HDL-C ratio. [Copyright &y& Elsevier]

The article discusses a variety of issues related to hydration, fluid balance and exercise. Hydration is a significant issue specially in sports performance. Water loss during exercise should be replaced at equal rate. The influence of caffeine on hydration is discussed. Clinical information on hyponatremia, creatinine supplementation and exercise-associated cramps is provided.

Abstract: The current investigation examined the effect of variations in protein intake on Whole body protein turnover (WBPTO) at rest in endurance-trained males. Whole body protein turnover is influenced by both diet and exercise. Whether endurance athletes require more protein than the non-exerciser remains equivocal. Five male runners (21.3 ± 0.3 years, 179 ± 2 cm, 70.6 ± 0.1 kg, 8.7% ± 0.4% body fat, 70.6 ± 0.1 V˙o 2max) participated in a randomized, crossover design diet intervention where they consumed either a low-protein (LP; 0.8 g/kg), moderate-protein (MP; 1.8 g/kg), or high-protein (HP; 3.6 g/kg) diet for 3 weeks. Whole body protein turnover (Ra, leucine rate of appearance; NOLD, nonoxidative leucine disposal; and Ox, leucine oxidation), nitrogen balance, and substrate oxidation were assessed at rest following each dietary intervention period. The HP diet increased leucine Ra (indicator of protein breakdown; 136.7 ± 9.3, 129.1 ± 7.4, and 107.8 ± 3.1 μmol/[kg · h] for HP, MP, and LP diets, respectively) and leucine Ox (31.0 ± 3.6, 26.2 ± 4.3, and 18.3 ± 0.6 μmol/[kg · h] for HP, MP, and LP diets, respectively) compared with LP diet (P < .05). No differences were noted in nonoxidative leucine disposal (an indicator of protein synthesis) across diets. Nitrogen balance was greater for HP diet than for MP and LP diets (10.2 ± 0.7, 1.8 ± 0.6, and −0.3 ± 0.5 for HP, MP, and LP diets, respectively). Protein oxidation increased with increasing protein intake (54% ± 6%, 25% ± 1%, and 14% ± 2% for HP, MP, and LP diets, respectively). Findings from this study show that variations in protein intake can modulate WBPTO and that protein intake approximating the current recommended dietary allowance was not sufficient to achieve nitrogen balance in the endurance-trained males in this investigation. Our results suggest that a protein intake of 1.2 g/kg or 10% of total energy intake is needed to achieve a positive nitrogen balance. This is not a concern for most endurance athletes who routinely consume protein at or above this level. [Copyright &y& Elsevier]

Abstract: The supplement Cortitrol was formulated to mitigate the cortisol response to physiological and psychological stress. Therefore, the purpose of this study was to examine the effects of Cortitrol on serum cortisol concentrations before, during, and after a high-intensity resistance exercise protocol (EX) and a resting control day (REST). We used a matched, balanced, randomized, double-blind, placebo-controlled, cross-over design. Blood samples were obtained at matching time points during EX and REST. Cortitrol significantly (P < .05) reduced cortisol area under the curve concentrations during REST. During EX, Cortitrol reduced cortisol concentrations at 20, 10, and 0 minutes pre-exercise, at mid-exercise, immediately post-exercise, and at 5 minutes post-exercise. In addition, serum cortisol and plasma adrenocorticotropin hormone area under the curve concentrations during EX were significantly lower after Cortitrol than placebo. Furthermore, Cortitrol significantly reduced free radical production. This was indicated by significantly lower plasma malondialdehyde concentrations at the 65-minute post-exercise time point during REST, and at pre-exercise, immediate post-exercise, and 65 minutes post-exercise during EX. Serum total testosterone, free testosterone, dehydroepiandrosterone, and growth hormone showed exercise-induced increases but no treatment effects. These data demonstrate that Cortitrol was effective in modulating the physiological stress responses of exercise from the anticipatory rises before physical stress and into early recovery by reducing cortisol and associated free radical production. [Copyright &y& Elsevier]

The purpose of this study was to examine the responses of growth hormone (GH) and insulin-like growth factor-I (IGF I) to intense heavy resistance exercise in highly trained men and women to determine what sex-dependent responses may exist. Subjects were highly resistance trained men (N = 8, Mean ± SD; age, yrs., 21 ± 1, height, cm, 175.3 ± 6.7, body mass, kg, 87.0 ± 18.5, % body fat, 15.2 ± 5.4, squat X body mass, 2.1 ± 0.4; and women (N = 7; Mean ± SD, age, yrs. 24 ± 5, height, cm 164.6 ± 6.7, body mass, kg 76.4 ± 8.8, % body fat, 26.9 ± 5.3, squat X body mass, 1.7 ± 0.6). An acute resistance exercise test protocol (ARET) consisted of 6 sets of 10 repetitions at 80% of the 1 RM with 2 min rest between sets was used as the stressor. Blood samples were obtained pre-exercise, after 3 sets, and then immediately after exercise (IP), 5, 15, 30, and 70 min post-exercise for determination of blood lactate (HLa), and plasma glucose, insulin, cortisol, and GH. Determination of plasma concentrations of IGF I, IGF binding proteins 1, 2, and 3 along with molecular weight isoform factions were determined at pre, IP and 70 min. GH significantly (P ≤ 0.05) increased at all time points with resting concentrations significantly higher in women. Significant increases were observed for HLa, glucose, insulin, and cortisol with exercise and into recovery with no sex-dependent observations. Women showed IGF-I values that were higher than men at all times points with both seeing exercise increases. IGFBP-1 and 2 showed increase with exercise with no sex-dependent differences. IGFBP-3 concentrations were higher in women at all-time points with no exercise induced changes. Both women and men saw an exercise induced increase with significantly higher values in GH in only the mid-range (30-60 kD) isoform. Only women saw an exercise induced increase with significantly higher values for IGF fractions only in the mid-range (30–60 kD) isoform, which were significantly greater than the men at the IP and 70 min post-exercise time points. In conclusion, the salient findings of this investigation were that in highly resistance trained men and women, sexual dimorphisms exist but appear different from our prior work in untrained men and women and appear to support a sexual dimorphism related to compensatory aspects in women for anabolic mediating mechanisms in cellular interactions. • Women differentiated their responses from men with higher concentrations of GH at rest and in mid-range fraction of GH • Women showed higher IGF-I concentrations at rest and recovery with a differential mid-range molecular weight fraction. • Plasma levels of growth hormone dimers are significantly higher in blood after exercise. • While sexual dimorphisms exist, they are different s than previously observed in untrained men and women. [ABSTRACT FROM AUTHOR]

The purpose of this study was to examine the influence of a novel "floatation-restricted environmental stimulation therapy" (floatation-REST) on growth hormone responses to an intense resistance exercise stress. Nine resistance trained men (age: 23.4 ± 2.5 yrs.; height: 175.3 ± 5.4 cm; body mass: 85.3 ± 7.9 kg) completed a balanced, crossover-controlled study design with two identical exercise trials, differing only in post-exercise recovery intervention (i.e., control or floatation-REST). A two-week washout period was used between experimental conditions. Plasma lactate was measured pre-exercise, immediately post-exercise and after the 1 h. recovery interventions. Plasma iGH was measured pre-exercise, immediately-post exercise, and after the recovery intervention, as well as 24 h and 48 h after the exercise test. The bGH-L was measured only at pre-exercise and following each recovery intervention. For both experimental conditions, a significant (P ≤ 0.05) increase in lactate concentrations were observed immediately post-exercise (~14 mmol • L-1) and remained slightly elevated after the recovery condition. The same pattern of responses was observed for iGH with no differences from resting values at 24 and 48 h of recovery. The bGH-L showed no exercise-induced changes following recovery with either treatment condition, however concentration values were dramatically lower than ever reported. The use of floatation-REST therapy immediately following intense resistance exercise does not appear to influence anterior pituitary function in highly resistance trained men. However, the lower values of bGH suggest dramatically different molecular processing mechanisms at work in this highly trained population. • Growth hormone-like molecules not affected by a novel floatation-REST therapy. • Dramatically lower bioactive growth hormone in highly resistance trained men. • Highly resistance trained men appear to process bioactive growth hormone differently. [ABSTRACT FROM AUTHOR]

Background: The minimum duration of exercise needed to acutely lower blood pressure (BP) has not been established. The purpose of this study is to compare the effects of short and long duration on the BP response to a session of aerobic exercise. Methods: Subjects were 45 men (mean ± SEM, 43.4 ± 1.5 years) with elevated BP (144.6 ± 1.6/85.2 ± 1.1 mm Hg). Using a parallel design, men were randomly assigned to 40% (LITE, n = 23) or 60% (MOD, n = 22) of maximal oxygen consumption. Following assignment, they completed 3 experiments: a no-exercise control, and a 15-minute SHORT and 30-minute LONG cycle bout. Subjects left the laboratory wearing an ambulatory BP monitor. Repeated measure analysis of variance tested if BP differed among experimental conditions (no-exercise control, LONG, and SHORT) and over time within groups (LITE and MOD). Results: For 9 hours, systolic BP increased from baseline after all conditions (P < .001); however, systolic BP was reduced by 5.6 ± 2.0 and 4.3 ± 1.6 mm Hg after SHORT and LONG with LITE, and 4.1 ± 1.6 and 4.9 ± 1.9 mm Hg with MOD, respectively, compared with no-exercise control (P < .05). For 9 hours, diastolic BP (DBP) decreased from baseline after all conditions (P < .001). DBP was reduced by 2.1 ± 1.0 and 3.6 ± 1.4 mm Hg after SHORT and LONG with MOD for 3 hours (P < .05), and average DBP was lower by 2.4 ± 1.0 mm Hg after LONG with LITE for 9 hours versus no-exercise control (P < .05). Conclusions: The immediate BP-lowering effects of short-duration, lower intensity exercise are comparable to those of higher amounts of exercise. Additional investigation is needed to better quantify the dose of exercise needed to lower BP. [Copyright &y& Elsevier]

Due to the important interactions of proenkephalin fragments (e.g., proenkephalin [107–140] Peptide F) to enhance activation of immune cells and potentially combat pain associated with exercise-induced muscle tissue damage, we examined the differential plasma responses of Peptide F to different exercise training programs. Participants were tested pre-training (T1), and after 8 weeks (T2) of training. Fifty-nine healthy women were matched and then randomly assigned to one of four groups: heavy resistance strength training (STR, n = 18), high intensity endurance training (END, n = 14), combined strength and endurance training (CMB, n = 17), or control (CON, n = 10). Blood was collected using a cannula inserted into a superficial vein in the antecubital fossa with samples collected at rest and immediately after an acute bout of 6 X 10 RM in a squat resistance exercise before training and after training. Prior to any training, no significant differences were observed for any of the groups before or after acute exercise. With training, significant ( P ≤ 0.95) elevations were observed with acute exercise in each of the exercise training groups and this effect was significantly greater in the CMB group. These data indicate that in untrained women exercise training will not change resting of plasma Peptide F concentrations unless both forms of exercise are performed but will result in significant increases in the immediate post-exercise responses. Such findings appear to indicate adrenal medullary adaptations opioid production significantly altered with exercise training. [ABSTRACT FROM AUTHOR]

Abstract: Purpose: The purpose of this study was to examine the effects of resistance exercise on the hypothalamic–pituitary–adrenal axis (HPA) response to mental challenge, withdrawal symptoms, urge to smoke, and cognitive stress during 24-hour smoking abstinence. Methods: 8 sedentary smokers (mean±SD age: 20.1±1.7y; height: 171.6±10.8cm; body mass: 70.4±12.0kg; smoking history: 2.9±0.8y) completed a 24-hour ad libitum smoking trial (SMO) followed by two 24-hour smoking abstinence trials. During abstinence trials, participants performed six whole body resistance exercises (EX) or a control condition (CON) in the morning, followed by mental challenge tasks in the afternoon. Plasma adrenocorticotropin hormone (ACTH), and salivary and serum cortisol were measured during each visit at rest (REST), and then before (PRE-EX), immediately after (IP-EX), and 30min after exercise (30-EX); and before (PRE-MC), immediately after (IP-MC), and 30min after mental challenge (30-MC). Results: Resistance exercise significantly (p≤0.05) elevated plasma ACTH and serum cortisol at IP-EX during EX compared with SMO and CON trials. Resting ACTH, salivary and serum cortisol concentrations at Pre-MC did not differ between EX and CON trials. The HPA axis response to mental challenge was similar after EX and CON trials. Finally, resistance exercise did not reduce withdrawal symptoms, urge to smoke, or stress. Conclusion: Resistance exercise did not substantially alter resting HPA hormones or the HPA response to mental challenge tasks during 24h of smoking abstinence. [Copyright &y& Elsevier]

Abstract: Statins positively impact plasma low-density lipoprotein cholesterol, inflammation and vascular endothelial function (VEF). Carbohydrate restricted diets (CRD) improve atherogenic dyslipidemia, and similar to statins, have been shown to favorably affect markers of inflammation and VEF. No studies have examined whether a CRD provides additional benefit beyond that achieved by habitual statin use. We hypothesized that a CRD (<50 g carbohydrate/d) for 6 weeks would improve lipid profiles and insulin sensitivity, reduce blood pressure, decrease cellular adhesion and inflammatory biomarkers, and augment VEF (flow-mediated dilation and forearm blood flow) in statin users. Participants (n = 21; 59.3 ± 9.3 y, 29.5 ± 3.0 kg/m2) decreased total caloric intake by approximately 415 kcal at 6 weeks (P < .001). Daily nutrient intakes at baseline (46/36/17% carb/fat/pro) and averaged across the intervention (11/58/28% carb/fat/pro) demonstrated dietary compliance, with carbohydrate intake at baseline nearly 5-fold greater than during the intervention (P < .001). Compared to baseline, both systolic and diastolic blood pressure decreased after 3 and 6 weeks (P < .01). Peak forearm blood flow, but not flow-mediated dilation, increased at week 6 compared to baseline and week 3 (P ≤ .03). Serum triglyceride, insulin, soluble E-Selectin and intracellular adhesion molecule-1 decreased (P < .01) from baseline at week 3, and this effect was maintained at week 6. In conclusion, these findings demonstrate that individuals undergoing statin therapy experience additional improvements in metabolic and vascular health from a 6 weeks CRD as evidenced by increased insulin sensitivity and resistance vessel endothelial function, and decreased blood pressure, triglycerides, and adhesion molecules. [Copyright &y& Elsevier]

Abstract: Normative values and confidence intervals for the hydration indices of women do not exist. Also, few publications have precisely described the fluid types and volumes that women consume. This investigation computed seven numerical reference categories for widely used hydration biomarkers (eg, serum and urine osmolality) and the dietary fluid preferences of self-reported healthy, active women. Participants (n=32; age 20±1 years; body mass 59.6±8.5 kg; body mass index [calculated as kg/m2] 21.1±2.4) were counseled in the methods to record daily food and fluid intake on 2 consecutive days. To reduce day-to-day body water fluctuations, participants were tested only during the placebo phase of the oral contraceptive pill pack. Euhydration was represented by the following ranges: serum osmolality=293 to 294 mOsm/kg; mean 24-hour total fluid intake=2,109 to 2,506 mL/24 hours; mean 24-hour total beverage intake=1,300 to 1,831 mL/24 hours; urine volume=951 to 1,239 mL/24 hours; urine specific gravity=1.016 to 1.020; urine osmolality=549 to 705 mOsm/kg; and urine color=5. However, only 3% of women experienced a urine specific gravity <1.005, and only 6% exhibited a urine color of 1 or 2. Water (representing 45.3% and 47.9% of 24-hour total fluid intake), tea, milk, coffee, and fruit juice were consumed in largest volumes. In conclusion, these data provide objective normative values for hyperhydration, euhydration, and dehydration that can be used by registered dietitians and clinicians to counsel women about their hydration status. [Copyright &y& Elsevier]

Abstract: Caffeine (CAF) ingestion may enhance endurance exercise by lowering perceived exertion (RPE) and muscle pain. However, exercise in the heat may be detrimental to performance by increasing RPE and pain. The purpose of this study was to examine if caffeine affects pain and related perceptual responses differently in cool and hot ambient conditions. Eleven male cyclists (mean±SD; age, 25±6years; mass, 72.6±8.1kg; VO2max, 58.7±2.9mlkg−1 min−1) completed four trials in a randomized, double blind design. While remaining euhydrated, subjects cycled for 90min at 65±7% VO2max followed by a 15-min performance trial. Subjects ingested 3mgkg−1 of encapsulated caffeine (CAF) or placebo (PLA) 60min before and 45 after beginning exercise in 12°C and 33°C (i.e., 12-CAF, 33-CAF, 12-PLA, and 33-PLA trials). Central, local, and overall perceived exertion (C-, L-, and O-RPE) and pain were measured throughout exercise. Throughout submaximal exercise C-, L-, and O-RPE were significantly greater in 33°C (P <0.05) but were not affected by CAF (P >0.05). Using area-under-the-curve analysis, pain in 33-PLA was increased by 74% vs 12-PLA (P <0.05). CAF did not reduce pain in 12°C (P =0.542), but in 33°C, CAF reduced pain by 27% (P =0.032). Despite this apparent advantage, CAF improved performance independent of ambient temperature (i.e., non-significant interaction; P =0.662). This study found that, although caffeine improves exercise capacity, its effect on leg muscle pain is dependent on ambient temperature. Although exercise in the heat increases muscle pain compared to a cooler environment, caffeine reduces this pain. [ABSTRACT FROM AUTHOR]

Abstract: To determine the effects of Vicoprofen®, Ibuprofen, and a placebo on the responses of endogenous opioid peptides following eccentric exercise-induced muscle damage 36 healthy men (age: 22.8 years; height: 178.8±6.2cm; body mass: 78.9±13.7kg; body fat: 15.8±6.5%) volunteered to participate in the study. Each participant was evaluated for pain 24h post and randomly assigned to an experimental group: VIC (Vicoprofen®), IBU (Ibuprofen), or P (placebo). Medication was given four times daily (i.e., VIC (hydrocodone bitartrate 7.5mg with Ibuprofen 200mg) and IBU 200mg). Blood was obtained at rest and at 0, 24, 48, 72, 96 and 120h following the eccentric exercise damage protocol. No significant changes for B-END were observed in the resting values over the recovery period among any of the treatment conditions. Conversely for plasma P-F, VIC and IBU had significantly (P <0.05) higher plasma concentrations of P-F above placebo at 24, 48, 72, and 96 and 120h with VIC higher than IBU and placebo conditions at 48, 72, 96, and 120h. Significant resting elevations were observed for P-F from pre-exercise at 48, 72, 96, and 120h for VIC; at 72 and 96h for IBU and no changes in the placebo treatment. Less tissue damage (MRI analyses), improved physical function as well as reduced pain was observed for the VIC condition over IBU and placebo. These data indicate that exogenous medications appear to be differentially stimulating the peripheral (adrenal medulla) opioid neuroendocrine responses as measured by plasma concentrations. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to examine the acute effect of resistance exercise (RE) on muscle androgen receptor (AR) and glucocorticoid receptor (GR) protein content. Fifteen resistance-trained men (n =8; 21±1 years, 175.3±6.7cm, 90.8±11.6kg) and women (n =7; 24±5 years, 164.6±6.7cm, 76.4±15.6kg) completed 6 sets of 10 repetitions of heavy squats. Blood samples were obtained before RE, after 3 and 6 sets of squats, and 5, 15, 30 and 70min after RE. Muscle biopsies from the vastus lateralis were obtained before RE, and 10min and 70min after RE. Blood samples were analyzed for total and free testosterone concentrations and muscle samples were analyzed for AR and GR protein content. Circulating total testosterone increased significantly (p ≤0.05) in men and free testosterone increased in men and women with exercise. AR was significantly reduced at 70min post-exercise in men and at 10min post-exercise in women compared to pre-exercise. There were no changes in GR following RE, but GR was significantly higher in women compared to men. These findings support a current paradigm for stabilization followed by a reduction and then a rebound in the acute AR response to RE but demonstrate that gender differences exist in the timeline of the AR response. [Copyright &y& Elsevier]

Abstract: Prescribing exercise based on intensity, frequency, and duration of loading may maximize osteogenic responses in bone, but a model of the osteogenic potential of exercise has not been established in humans. In rodents, an osteogenic index (OI) has been used to predict the osteogenic potential of exercise. The current study sought to determine whether aerobic, resistance, or combined aerobic and resistance exercise programs conducted over eight weeks and compared to a control group could produce changes in biochemical markers of bone turnover indicative of bone formation. We further sought to determine whether an OI could be calculated for each of these programs that would reflect observed biochemical changes. We collected serum biomarkers [bone-specific alkaline phosphatase (BAP), osteocalcin, tartrate-resistant acid phosphatase (TRAP), C-terminal telopeptide fragment of type I collagen (CTx), deoxypyridinoline (DPD), 25-hydroxy vitamin D (25(OH)D), and parathyroid hormone (PTH)] in 56 women (20.3±1.8 years) before, during and after eight weeks of training. We also measured bone mineral density (BMD) at regional areas of interest using DXA and pQCT. Biomarkers of bone formation (BAP and osteocalcin) increased in the Resistance and Combined groups (p <0.05), while biomarkers of bone resorption (TRAP and DPD) decreased and increased, respectively, after training (p <0.05) in all groups. Small changes in volumetric and areal BMD (p <0.05) were observed in the distal tibia in the Aerobic and Combined groups, respectively. Mean weekly OIs were 16.0±1.9, 20.6±2.2, and 36.9±5.2 for the Resistance, Aerobic, and Combined groups, respectively. The calculated osteogenic potential of our programs did not correlate with the observed changes in biomarkers of bone turnover. The results of the present study demonstrate that participation in an eight week physical training program that incorporates a resistance component by previously inactive young women results in alterations in biomarkers of bone remodeling indicative of increased formation without substantial alterations in markers of resorption. [Copyright &y& Elsevier]

Abstract: The purpose of this study was to determine the influence of endogenous circulating testosterone (T) on muscle androgen receptor (AR) responses to acute resistance exercise (RE). Six healthy men (26±4 years; 176±5cm; 75.8±11.4kg) performed a knee extension exercise protocol on two occasions separated by 1–3 weeks. Rest preceded one trial (i.e., control [CON] trial) and a high-volume upper-body RE protocol designed to increase circulating T preceded the other trial (i.e., high T [HT] trial). Serial blood samples were obtained throughout each trial to determine circulating T concentrations. Biopsies of the vastus lateralis were obtained pre-RE (REST), 10-min post-RE (+10), and 180-min post-RE (+180) to determine muscle AR content. Circulating T concentrations remained stable during CON. Alternately, HT significantly (p ≤0.05) increased T concentrations above resting values (+16%). Testosterone area-under-the-time curve during HT exceeded CON by 14%. AR content remained stable from REST to +10 in both trials. Compared to the corresponding +10 value, muscle AR content at +180 tended to decrease during CON (−33%; p =0.10) but remained stable during HT (+40%; p =0.17). Muscle AR content at +180 during the HT trial exceeded the corresponding CON value. In conclusion, acute elevations in circulating T potentiated muscle AR content following RE. [Copyright &y& Elsevier]

Because carnitine has been shown to decrease oxidative stress and improve endothelial cell functioning, we examined the effects of carnitine supplementation on postprandial flow-mediated dilation (FMD) and circulating biomarkers of inflammation and oxidative stress after a high-fat meal. A randomized, double-blind, placebo-controlled, crossover study design was used. Thirty men and women (age 30 ± 8 year, body mass 72.9 ± 17.1 kg, body fat 13.0 ± 6.4%) participated in 2 vascular testing days, each preceded by 3 weeks of supplementation with either 2 g/day of l -Carnitine ( l -Carnitine l -Tartrate) or placebo with a 3- to 5-week washout period between trials. Brachial artery FMD in response to 5 minutes of upper arm occlusion and circulating markers of oxidative stress and inflammation were measured in the fasting state and after a standardized high-fat meal. After 3 weeks of supplementation, peak FMD in the fasting state was similar between the carnitine and placebo trials, averaging 6.6%. Peak FMD during the postprandial period decreased to 5.8% at 1.5 hours during placebo and increased to 7.7% during the carnitine trial (n = 30: p = 0.043 for supplement by time interaction effect). This improvement in postprandial vascular function was most dramatic in subjects who showed a decrease in peak FMD in response to the meal (n = 15: p = 0.003 for supplement by time interaction effect). There was a significant increase in postprandial lipemia and plasma interleukin-6 but no effect of supplementation. There were no significant postprandial changes or supplement effects for plasma tumor necrosis factor-alpha and malondialdehyde. In conclusion, consistent with other work showing a beneficial effect of carnitine on vascular function, these findings indicate that carnitine supplementation in healthy individuals improves postprandial FMD after a high-fat meal. [Copyright &y& Elsevier]

Abstract: The purpose of the present investigation was to examine androgen receptor (AR) content in the vastus lateralis following two resistance exercise protocols of different volume. Nine resistance-trained men (age=24.3±4.4 years) performed the squat exercise for 1 (SS) and 6 sets (MS) of 10 repetitions in a random, counter-balanced order. Muscle biopsies were performed at baseline, and 1h following each protocol. Blood was collected prior to, immediately following (IP), and every 15min after each protocol for 1h. No acute elevations in serum total testosterone were observed following SS, whereas significant 16–23% elevations were observed at IP, 15, and 30min post-exercise following MS. No acute elevations in plasma cortisol were observed following SS, whereas significant 31–49% elevations were observed for MS at IP, 15, and 30min post-exercise. Androgen receptor content did not change 1h following SS but significantly decreased by 46% following MS. These results demonstrated that a higher volume of resistance exercise resulted in down-regulation of AR content 1h post-exercise. This may have been due to greater protein catabolism associated with the higher level of stress following higher-volume resistance exercise. [Copyright &y& Elsevier]

Abstract: This study aims to characterize the relationship between increased protein intake and hydration indexes. Five men participated in a 12-week, randomized, crossover, controlled diet intervention study. Subjects consumed eucaloric diets containing 3.6 (high protein), 1.8 (moderate protein), and 0.8 (low protein) g/kg/day of protein for 4 weeks each. Energy intakes were based on requirements established relative to resting energy expenditure and activity at baseline. Assessments included blood urea nitrogen, plasma osmolality, urine-specific gravity, and estimates of fluid balance. Repeated-measures analyses of variance and paired t tests were used to determine effects of treatment and time. Fluid intake and fluid balance were unaffected. Blood urea nitrogen was higher for high protein vs low protein and vs moderate protein, and urine-specific gravity was higher for high protein vs moderate protein. Baseline plasma osmolality was greater for high protein vs low protein and vs moderate protein. The effect of increasing dietary protein on fluid status was minimal. [Copyright &y& Elsevier]

Abstract: Background: A sedentary lifestyle is a major risk factor for cardiovascular and thrombotic complications. While habitual endurance activity will reduce the risk of these adverse events, the influence of habitual resistance exercise is less clear. This study examined coagulation and fibrinolytic responses to an acute exhaustive resistance exercise test (AERET) in both resistance-trained (RT, min 2yr, 5 men and 5 women) and untrained (UT, 5 men and 5 women) subjects. Methods: The AERET consisted of six sets of 10 repetitions of squats at 80% of 1-repetition maximum. Venous blood was collected pre-exercise, immediate post exercise (IP), and +15, +60, and +120minutes post exercise. Results: Compared to UT, RT exhibited a lower capacity to form a clot as seen by activated partial Thromboplastin time (aPTT) integrated area under the curve over time (iAUC) levels, lower pre-exercise and 120min post-exercise plasminogen activator inhibitor −1 (PAI-1) activity, and higher tissue plasminogen activator (tPA) activity immediately post-exercise. There were no significant differences between RT and UT for fibrinogen, prothrombin fragment 1+2 (PTF 1+2), and thrombin-antithrombin complexes (TAT). Conclusion: These results suggest that habitual resistance exercise training may provide an enhanced fibrinolytic state. [Copyright &y& Elsevier]

Abstract: Objective: A polymorphism (−786 T>C) in the promoter region of the endothelial nitric oxide synthase gene (eNOS) has important functional characteristics. We examined the influence of eNOS −786 T>C (rs2070744) on the BP and NO response to acute dynamic exercise. Methods: Subjects (n =49, 43.7±1.4yr) had pre- to Stage-1 hypertension (145.6±1.5/85.9±1.1mmHg). Volunteers performed three experiments; a non-exercise control session, and two cycle exercise bouts at 40% (LIGHT) and 60% (MODERATE) of peak oxygen consumption. Subjects wore an ambulatory BP monitor upon leaving the laboratory. NO was measured by chemiluminescence assay before (baseline), during, and after the experiments. eNOS genotypes were determined by polymerase chain reaction and restriction enzyme digestion. Repeated measure ANOVA tested if BP and NO differed over time among experiments and by eNOS genotypes (n =25, TT; n =24, TC/CC). Results: Among carriers of the eNOS C786 allele, systolic BP (SBP) was reduced 5.3±2.4mmHg after MODERATE versus non-exercise control over 9h compared to those with the eNOS T786T genotype (p <0.05). Under these conditions, SBP tended to be lower 4.6±2.9mmHg after LIGHT (p =0.076). The exercise-induced diastolic BP and NO responses were not different from non-exercise control between eNOS genotype (p >0.05). Conclusion: Men who were carriers of the eNOS C786 allele responded more favorably to the antihypertensive effects of aerobic exercise than men with the eNOS T786T genotype. The eNOS C786 allele is associated with reduced eNOS gene transcription and promoter activity. Future work is needed to determine how exercise may override genetic predispositions to down regulate eNOS gene activity. [Copyright &y& Elsevier]