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We investigated the effects of 12 weeks of high-intensity interval training (HIIT) on selected circulating adipokines and other cardiovascular diseases risks factors in men with obesity. Thirty men with obesity (age: 24.96±3.11 year, BMI: 30.92±1.04 kg/m2) were randomly assigned to HIIT and control groups. The HIIT group participated in a 12-week HIIT program (5×2 min interval bout at an intensity of 85–95% HRmax interspersed by 1 min passive recovery, three times per week), while the control group maintained their usual lifestyles. Blood lipids, insulin resistance, and select serum adipokines were assessed before and after 12 weeks of the intervention period. HIIT improved body composition and lipid profiles (p

The aim of this study was to explore the effect of one bout of aerobic exercise on epinephrine, norepinephrine, cortisol, glucose, lactate, and free fatty acid (FFA) responses in breast cancer survivors and healthy controls. 9 female breast cancer survivors and 9 women without a history of cancer completed 30 min of cycle ergometry exercise at 60 % of VO2peak. Blood samples were taken pre-exercise, immediately post-exercise, and 2 h post-exercise from which plasma concentrations of study variables were measured. Immediately and 2 h post-exercise, increases were observed in epinephrine (control group only) norepinephrine (both groups), lactate (both groups), and FFA (both groups immediately post-exercise; breast cancer survivor group only at 2 h post-exercise) (p < 0.05). Cortisol decreased immediately and 2 h post-exercise in the control group while glucose decreased immediately post-exercise in the breast cancer survivor group (p < 0.05). In conclusion, breast cancer survivors appeared to display attenuated epinephrine, cortisol, and lactate responses while displaying larger magnitude changes in glucose and FFA responses compared to controls. These preliminary findings may have implications for the regulation of metabolism during exercise in breast cancer survivors.

Leptin (L) is associated with body-weight-regulating and adipostatic functions. Its receptors also may be found centrally. Thyroid hormones regulate metabolic processes mainly by binding at peripheral receptors. Aim of this study was to show if there is a link between those central and peripheral regulation systems and to investigate the influence of different training intensities on L and the hypothalamic-thyroid-axis (HTA) in highly trained rowers. Six rowers (18.9 +/- 2.6 y; BMI 22.8 +/- 2.1 kg/m (2)) undertook high intensity resistance training (RT) for three weeks followed by three weeks of endurance training (ET). After each training cycle the subjects had one week for recovery (R1, R2). Blood samples were taken before and at the end of RT, R1, ET and R2. L, thyroid stimulating hormone (TSH), free T3 (fT3) and free T4 (fT4) were measured. After RT, a significant reduction in L, TSH and fT3 was found (p < 0.05). fT4 was unchanged. L remained decreased until the end of R1. After ET, a significant increase of TSH was found. L correlated to basal TSH levels (r = 0.49, p = 0.006) during R. BMI and body fat were unchanged throughout the study and were not correlated with hormonal levels. We speculate a high energy flux during intensified training (RT) caused the decrease of L and the HTA, independent of BMI or body fat. Thus, we conclude a depression of L and HTA is associated with training intensity.

This study compared cardio-respiratory responses during running wearing a motion control shoe (MC) or a cushioning shoe (CU) in a cross-over single blinded design. Fourteen runners (10F/4M, age=27.3+/-5.1 years, body mass=64.1+/-12.2 kg, height=167.8+/-7.5 cm, VO (2)max=52.3+/-8.8 ml/kg/min) completed a 40-min run at approximately 65% VO (2) max under both shoe conditions. Oxygen uptake (mL/kg/min; L/min), minute ventilation (L/min), respiratory exchange ratio, and heart rate were measured at minutes 8-10, 18-20, 28-30 and 38-40 of exercise. Rating of perceived exertion was obtained at minutes 10, 20, 30 and 40. Two (footwear) by four (time) repeated measures ANOVAs showed no differences between footwear conditions in overall oxygen consumption (MC=36.8+/-1.5 vs. CU=35.3+/-1.4 mL/kg/min, p=0.143), minute ventilation (MC=50.4+/-4 vs. CU=48.5+/-3.8, p=0.147), respiratory exchange ratio (MC=0.90+/-0.01 vs. CU=0.89+/-0.01, p=0.331), heart rate (MC=159+/-3 vs. CU=160+/-3, p=0.926), or rate of perceived exertion. The design of motion control footwear does not appear to affect cardio-respiratory or perceived exertion responses during submaximal running. The findings are specific to the shoes tested. Nonetheless, the outcomes suggest that footwear selection to reduce certain overuse injuries does not increase the work of running.

The hypothalamic-pituitary-testicular (H-P-T) axis was evaluated in groups of endurance-trained (TRG) and untrained (UNT) males. Each group was subjected to: 1) a 4-h resting hormonal profile [testosterone (T), free-testosterone (FT), estradiol (E2), luteinizing hormone (LH), prolactin (PRL), and cortisol (C)], 2) a dopamine antagonist (DA; 10 micrograms.kg-1 body weight) challenge to the pituitary-testes, and 3) a gonadotropin-releasing hormone (GnRH; 120 micrograms.kg-1 body weight) challenge to the pituitary-testes. Compared to UNT, the TRG resting T (4.8 +/- 0.7 vs 7.1 +/- 1.2 ng.ml-1, p = 0.05) and PRL (3.3 +/- 1.4 vs 7.0 +/- 2.3 ng.ml-1, p = 0.09) were lower while LH was elevated (15.0 +/- 1.8 vs 11.8 +/- 1.5 mIU.ml-1, p = 0.06). The DA challenge produced a greater integrated PRL response in the TRG (2962.7 +/- 265.1 ng +/- ml-1.min) than in the UNT (1735.3 +/- 282.0 ng.ml-1.min; p = 0.01). No significant changes were observed in T following the DA-induced PRL rise. The TRG had a blunted LH response (817.2 +/- 111.6 mIU.ml-1.min) following the GnRH injection as compared to the UNT (1493.7 +/- 213.4 mIU.ml-1.min; P less than 0.02). T levels were significantly (p less than 0.03) increased in both groups by the LH rise after the GnRH challenge (TRG = 9.9 +/- 5.0%; UNT = 8.6 +/- 9.9%, respectively), but no significant between group differences were observed. Results suggest endurance training produces an enhanced PRL and attenuated LH release by the pituitary.(ABSTRACT TRUNCATED AT 250 WORDS)

Six eumenorrheic females (age = 26.3 +/- 2.4 yrs; X +/- SE) exercised until exhaustion (EE; 70% VO2max) at the midluteal (LP, 7-8 days after ovulation) and midfollicular (FP, days 7-8) phases of their menstrual cycles. Phases were confirmed by estradiol and progesterone concentrations. Each EE test was preceded by a depletion exercise bout (DE; 90 min, 60% VO2max and 4 x 1 min, 100% VO2max) and 3 days of rest/diet control. Muscle biopsies 1% (vastus lateralis) were taken post-DE, pre-EE, and post-EE and then analyzed for glycogen content. There was a strong tendency (P less than 0.07) for EE duration to be greater during LP (139.2 +/- 14.9 min) than FP (126 +/- 17.5 min). Glycogen repletion (pre-EE minus post-DE) following DE was greater (P = 0.05) during the LP than FP (88.2 +/- 4.7 vs 72.8 +/- 5.7 mumol/g w. w. muscle). However, EE glycogen utilization (pre-EE minus post-EE/EE time) did not differ between phases (LP = 0.41 +/- 0.08 mumol/g w. w. muscle/min vs FP = 0.33 +/- 0.11 mumol/g w. w. muscle/min; P = 0.17). The results suggest that exercise performance and muscle glycogen content are enhanced during the LP of the menstrual cycle. These findings imply athletic performance may be affected by the phases of the menstrual cycle.