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Cycle training is an important training modality of elite rowers. Cycling is the preferred alternative to on-water and ergometer rowing as it provides a reduction in compressive forces on the thoracic cage and upper extremities while still creating a local and central acclimation to endurance training. It is hypothesised, however, that there will be differences in physiological characteristics between Concept II (CII) rowing and WattBike (WB) cycling due to the principle regarding the specificity of training that elite rowers undertake. Understanding these differences will ensure more accurate training prescription when cycling. Twenty international level male rowers, [ V ˙ O2PEAK 5.85 ± 0.58 L.min-1 (CI ± 0.26 L.min-1)] participated in two identical discontinuous incremental exercise tests on a CII rowing and WB cycle ergometer. Ergometer modalities were randomised and counterbalanced among the group and tests occurred 7 days apart. V ˙ O2, V ˙ CO2, V ˙ E(STPD) and HR were significantly higher for every submaximal power output on the CII compared with the WB. Maximal power output on the WB was higher than on the CII [42 ± 33 W (CI ± 14 W) p V ˙ O2PEAK was similar between modalities. Minute ventilation at maximal exercise was 11 L.min-1 lower on CII than on WB. When data were expressed relative to modality specific V ˙ O2PEAK, power output was consistently lower on the CII as was submaximal V ˙ CO2, RER, RPE, mechanical efficiency and BLa concentration at 75% V ˙ O2PEAK. Across all power outputs and exercise modalities, 77% of the variance in RPE could be explained by the variance in BLa. These results demonstrate that elite rowers can attain similar V ˙ O2PEAK scores regardless of modality. Substantial physiological and metabolic differences are evident between CII rowing and WB cycling when power output is the independent variable with the latter being over 40 W higher. The difference in displayed power output between the ergometer modalities is attributed to differences in mechanical efficiency and a degree of power output not being accounted for on the CII ergometer. Given the lack of consistency between CII and WB power output, other physiological measures, such as HR, are better suited to prescribe WB ergometer sessions.

The majority of lightweight rowers undertake acute weight loss prior to competition. Given the competitive advantage afforded to larger, more muscular rowers over their smaller counterparts, the use of moderate, acute weight loss may be justified, at least among larger, leaner athletes who struggle to achieve the specified body mass requirement and have limited potential for further body mass loss via reductions in body fat. The performance implications of moderate acute weight loss appear to be small on the ergometer and may be even less on water, at least when aggressive recovery strategies are adopted between weigh-in and racing. Furthermore, any performance implications of acute weight loss are not exacerbated when such weight loss is undertaken repeatedly throughout the course of a regatta, and may even be eliminated when aggressive recovery strategies are introduced before and after racing. The combination of adequate sodium, fluid and carbohydrate in line with current guidelines results in the best performances. While the performance implications of modest acute weight loss may still need to be considered in regard to competition outcome, chronic body mass strategies may not be without performance implications. This is especially the case for athletes who have very low levels of body fat and/or athletes who decrease their body mass too quickly. Further studies are needed to address the degree of weight loss that can be tolerated with minimal health and/or performance implications, and the optimal time frame over which this should occur. Possible adaptation to the physiological state that accompanies acute weight loss also warrants investigation.

High altitude exposure can increase resting metabolic rate (RMR) and induce weight loss in obese populations, but there is a lack of research regarding RMR in athletes at moderate elevations common to endurance training camps. The present study aimed to determine whether 4 weeks of classical altitude training affects RMR in middle-distance runners. Ten highly trained athletes were recruited for 4 weeks of endurance training undertaking identical programs at either 2200m in Flagstaff, Arizona (ALT, n = 5) or 600m in Canberra, Australia (CON, n = 5). RMR, anthropometry, energy intake, and hemoglobin mass (Hbmass) were assessed pre- and posttraining. Weekly run distance during the training block was: ALT 96.8 ± 18.3km; CON 103.1 ± 5.6km. A significant interaction for Time*Group was observed for absolute (kJ.day-1) (F-statistic, p-value: F(1,8)=13.890, p = .01) and relative RMR (F(1,8)=653.453, p = .003) POST-training. No significant changes in anthropometry were observed in either group. Energy intake was unchanged (mean ± SD of difference, ALT: 195 ± 3921kJ, p = .25; CON: 836 ± 7535kJ, p = .75). A significant main effect for time was demonstrated for total Hbmass (g) (F(1,8)=13.380, p = .01), but no significant interactions were observed for either variable [Total Hbmass (g): F(1,8)=1.706, p = .23; Relative Hbmass (g.kg-1): F(1,8)=0.609, p = .46]. These novel findings have important practical application to endurance athletes routinely training at moderate altitude, and those seeking to optimize energy management without compromising training adaptation. Altitude exposure may increase RMR and enhance training adaptation,. During training camps at moderate altitude, an increased energy intake is likely required to support an increased RMR and provide sufficient energy for training and performance.

Purpose:The Concept II model C (IIC) rowing ergometer was replaced by the Concept II model D (IID), but the design modifications of the updated ergometer might alter resistance characteristics and rowing technique, thereby potentially influencing ergometer test results. This study evaluated the physiological response to rowing on the IIC and IID ergometers during a submaximal progressive incremental test and maximal-performance time trial.Methods:Eight national-level rowers completed submaximal and maximal tests on the IIC and IID ergometers separated by 48 to 72 h. Physiological responses and calculated blood lactate thresholds (LT1 and LT2) were compared between ergometer models (IIC vs IID) using standardized drag-factor settings.Results:Power output, oxygen consumption, rowing economy (mL O2 · min−1 · W−1), heart rate, blood lactate concentration, stroke rate, and rating of perceived exertion all displayed similar responses regardless of ergometer model. Calculated physiological values equivalent to LT1 and LT2 were also similar between models, except for blood lactate concentration at LT1, which displayed a small but statistically signifcant difference (P = .02) of 0.2 mmol/L.Conclusions:The physiological response when rowing on IIC and IID ergometers is nearly identical, and testing can therefore be carried out on either ergometer and the results directly compared.

Background Recent research has demonstrated decreases in resting metabolic rate (RMR), body composition and performance following a period of intensified training in elite athletes, however the underlying mechanisms of change remain unclear. Therefore, the aim of the present study was to investigate how an intensified training period, designed to elicit overreaching, affects RMR, body composition, and performance in trained endurance athletes, and to elucidate underlying mechanisms. Method Thirteen (n = 13) trained male cyclists completed a six-week training program consisting of a “Baseline” week (100% of regular training load), a “Build” week (~120% of Baseline load), two “Loading” weeks (~140, 150% of Baseline load, respectively) and two “Recovery” weeks (~80% of Baseline load). Training comprised of a combination of laboratory based interval sessions and on-road cycling. RMR, body composition, energy intake, appetite, heart rate variability (HRV), cycling performance, biochemical markers and mood responses were assessed at multiple time points throughout the six-week period. Data were analysed using a linear mixed modeling approach. Results The intensified training period elicited significant decreases in RMR (F(5,123.36) = 12.0947, p =

Objective: Tachykinins are mediators of airway hyper-reactivity and inflammation. There is in vitro evidence that ovine responses to tachykinins correlate closely to human responses. This study was designed to characterize the effect of intravenously administered tachykinins on sheep lung resistance in vivo to determine the effect of dose timing on reproducibility of responses and the induction of tachyphylaxis. We then used this information to help further characterize the response with several pharmacological agents. Methodology: Substance P (SP) was administered by infusion to conscious merino ewes and lung resistance (RL) was measured. Infusions were given at 30, 60, 120 min and 24 h intervals. The effect of various agents on the response to SP was then assessed. Results: Substance P led to a transient increase in RL, mean (± SEM) 754.8 (± 139)% of baseline, with marked tachyphylaxis at 30, 60 and 120 min. Phosphoramidon increased the peak response to 1151.5 ± 196%. Atropine and CP 96 345 abolished the response to SP, while indomethacin, sodium cromoglycate and pyrilamine had no significant effect. Substance P had a greater effect on RL than did neurokinin A. Conclusions: Substance P increases RL in sheep via a cholinergic mechanism which is mediated by NK-1 receptors, and is subject to tachyphylaxis. These findings have implications for the design of studies using the ovine model in the evaluation of tachykinin antagonists as potential therapeutic agents.

SLATER, G. J., A. J. RICE, K. SHARPE, D. JENKINS, and A. G. HAHN. Influence of Nutrient Intake after Weigh-In on Lightweight Rowing Performance. Med. Sci. Sports Exerc., Vol. 39, No. 1, pp. 184–191, 2007. Purpose: The aim of the present study was to compare the effectiveness of different nutritional recovery strategies between weigh-in and racing on 2000-m rowing ergometer performance among oarsmen undertaking short-term weight loss before competition. Methods: Competitive rowers (N = 12) completed four ergometer trials, each separated by 48 h. No weight restrictions were imposed for the first trial (TR1). Thereafter, athletes were required to reduce their body mass by 5.2% in the 24 h before trial 2 (TR2), again reaching this body mass before the final two trials (TR3 and TR4). Athletes were provided with one of three nutritional recovery strategies in the 2 h between weighin and racing in a counterbalanced fashion according to a Latin square design: fluid (2.8 kJIkg j1 , 0.0 gIkg j1 carbohydrate, 0.6 mgIkg j1 sodium, 28.5 mLIkg j1 fluid; FLU), carbohydrate/sodium (45.3 kJIkg j1 , 2.2 gIkg j1 carbohydrate, 32.9 mgIkg j1 sodium, 7.2 mLIkg j1 fluid; CHO), and a combination of water and carbohydrate/sodium (44.8 kJIkg j1 , 2.3 gIkg j1 carbohydrate, 33 mgIkg j1 sodium, 28.5 mLIkg j1 fluid; COM). Results: Performance was slower for CHO compared with both COM (mean difference, 4.13; 95% CI, 1.37–6.88 s; P = 0.003) and FLU (2.88; 95% CI, 0.13–5.63 s; P = 0.039). However, FLU was not significantly slower than COM (1.24; 95% CI, j1.41 to 3.90 s; P = 0.474). Conclusions: The present investigation has shown that although carbohydrate and sodium intake may be important in the recovery period between weigh-in and 2000-m rowing ergometer performance, fluid intake has a greater influence on performance among lightweight male rowers who undertake short-term weight loss to achieve specified

To strengthen the depth of lightweight rowing talent, we sought to identify experienced heavyweight rowers who possessed physique traits that predisposed them to excellence as a lightweight. Identified athletes (n = 3) were monitored over 16 wk. Variables measured included performance, anthropometric indices, and selected biochemical and metabolic parameters. All athletes decreased their body mass (range 2.0 to 8.0 kg), with muscle mass accounting for a large proportion of this (31.7 to 84.6%). Two athletes were able to maintain their performance despite reductions in body mass. However, performance was compromised for the athlete who experienced the greatest weight loss. In summary, smaller heavyweight rowers can successfully make the transition into the lightweight category, being nationally competitive in their first season as a lightweight.

OBJECTIVE These studies were conducted to test the hypothesis that isobaric hypoxia would switch OSA to central sleep apnoea (CSA). METHODS Five adult men (mean age 54.2 +/- 5.5 years, mean BMI 29.9 +/- 6.7 kg/m(2)) with moderate OSA underwent overnight polysomnography at three altitudes. The highest altitude was simulated in a normobaric hypoxic chamber. RESULTS The obstructive respiratory disturbance index fell from 25.5 +/- 14.4/h at 60 m to 17.3 +/- 9.2/h at 610 m and 0.5 +/- 0.7/h at 2750 m (P = 0.004 compared with 60 m). The central respiratory disturbance index rose from 0.4 +/- 0.5/h at 60 m to 8.1 +/- 5.8/h at 610 m and 78.8 +/- 29.7/h at 2750 m (P < 0.001 compared with 60 m). Mean sleep SaO(2) fell from 94 +/- 1% at 60 m to 93 +/- 1% at 610 m to 85 +/- 4% at 2750 m (P < 0.001 compared with 60 m). CONCLUSION Moderate severity OSA at sea level (60 m) was completely replaced by severe CSA at a simulated altitude of 2750 m. The authors believe that the OSA resolved because of an increased respiratory drive [corrected] and an increase in upper airway tone, whereas CSA developed because of hypocapnia in non-rapid eye movement sleep.

Purpose: The present study was conducted to examine the impact of acute weight loss on repeat 2000-m rowing ergometer performance during a simulated multiday regatta. and to compare two different body mass management strategies between races. Methods: Competitive rowers (N = 16) were assigned to either a control (CON), partial recovery (RECpartial), or complete recovery (RECcomplete) group. Volunteers completed four trials, each separated by 48 h. No weight restrictions were imposed for the first trial. Thereafter, athletes in RECpartial and RECcomplete were required to reduce their body mass by 4% in the 24 h before trial 2, again reaching this body mass before the final two trials. No weight restrictions were imposed on CON. Aggressive nutritional recovery strategies were used in the 2 h following weigh-in for all athletes. These strategies were maintained for the 12-16 h following racing for RECcomplete with the aim of restoring at least three quarters of the original 4% body mass loss. Postrace recovery strategies were less aggressive in RECpartial; volunteers were encouraged to restore no more than half of their initial 4% body mass loss. Results: Acute weight loss increased time to complete the first at-weight performance trial by a small margin (mean 3.0, 95% CI -0.3 to 6.3 s, P = 0.07) when compared with the CON response. This effect decreased when sustained for several day,. Aggressive postrace recovery strategies tended to eliminate the effect of acute Weight loss on subsequent performance. Conclusion: Acute weight loss resulted in a small performance compromise that was reduced or eliminated when repeated over several days. Athletes should be encouraged to maximize recovery in the 12-16 h following racing when attempting to optimize subsequent performance.

Purpose: Although the body-mass management strategies of athletes in high-participation weight-category sports such as wrestling have been thoroughly investigated, little is known about such practices among lightweight rowers. This study examined the body-mass management practices of lightweight rowers before competition and compared these with current guidelines of the International Federation of Rowing Association (FISA). Quantification of nutrient intake in the 1-2 h between weigh-in and racing was also sought. Methods: Lightweight rowers (N = 100) competing in a national regatta completed a questionnaire that assessed body-mass management practices during the 4 wk before and throughout a regatta plus recovery strategies after weigh-in. Biochemical data were collected immediately after weigh-in to validate questionnaire responses. Responses were categorized according to gender and age category (Senior B or younger than 23 yr old, i.e., U23, Senior A or OPEN, i.e., open age limit) for competition. Results: Most athletes (male U23 76.5%, OPEN 92.3%; female U23 84.0%, OPEN 94.1%) decreased their body mass in the weeks before the regatta at rates compliant with FISA guidelines. Gradual dieting, fluid restriction, and increased training load were the most popular methods of body-mass management. Although the importance of recovery after weigh-in was recognized by athletes, nutrient intake and especially sodium (male U23 5.3 P 4.9, OPEN 7.7 P 5.9; female U23 5.7 P 6.8, OPEN 10.2 P 5.4 mg-kg(-1)) and fluid intake (male U23 12.1 P 7.1, OPEN 13.5 P 8.1; female U23 9.4 P 7.4, OPEN 14.8 P 6.9 mL.kg(-1)) were below current sports nutrition recommendations. Conclusion: Few rowers were natural lightweights; the majority reduced their body mass in the weeks before a regatta. Nutritional recovery strategies implemented by lightweight rowers after weigh-in were not consistent with current guidelines.

Central apneas occur after cessation of mechanical ventilation despite normocapnic conditions. We asked whether this was due to ventilator-induced increases in respiratory rate or VT. Accordingly, we compared the effects of increased VT (135 to 220% of eupneic VT) with and without increased respiratory rate, using controlled and assist control mechanical ventilation, respectively, upon transdiaphragmatic pressure in sleeping humans. Increasing ventilator frequency +1 per minute and VT to 165-200% of baseline eupnea eliminated transdiaphragmatic pressure during controlled mechanical ventilation and prolonged expiratory time (two to four times control) after mechanical ventilation. During and after assist control mechanical ventilation at 135-220% of eupneic VT, transdiaphragmatic pressure was reduced in proportion to the increase in ventilator volume. However, every ventilator cycle was triggered by an active inspiration, and immediately after mechanical ventilation, expiratory time during spontaneous breathing was prolonged less than 20% of that observed after controlled mechanical ventilation at similar VT. We conclude that both increased frequency and VT during mechanical ventilation significantly inhibited respiratory motor output via nonchemical mechanisms. Controlled mechanical ventilation at increased frequency plus moderate elevations in VT reset respiratory rhythm and inhibited respiratory motor output to a much greater extent than did increased VT alone.

Introduction: A systematic approach to managing the training of elite athletes is supported by accurate training load measurement. However, quantifying the training of elite Australian rowers is complex due to unique challenges: 1) the multi-centre, multi-state structure of the national program; 2) the variety of training undertaken, incorporating rowing-specific and non-specific modalities, with continuous and interval efforts that span the full intensity spectrum; and 3) the limitations of existing quantification methods for capturing total training loads undertaken from varied training. These challenges highlighted a need to create a consistent, location-independent framework for prescribing training in elite rowing, with a capacity to account for varied training. Methods: An in-house proprietary measure (the T2minute method) was developed at the National Rowing Centre of Excellence (NRCE), as a collaborative project between sport scientists and national squad coaches. The design phase was informed by assessments of the existing training measures, and built upon standardised intensity zones established at the Australian Institute of Sport. A common measurement unit was chosen: one T2minute equates to one minute of on-water single scull rowing at T2 intensity (∼60–72% VO2max). Each intensity zone was assigned a weighting factor according to the curvilinear relationship between power output, intensity, and blood lactate response. Each training mode was assigned a weighting factor based on whether coaches perceived it to be “harder” or “easier” than onwater rowing. With coaches’ feedback, the method was refined over a period of five months. The T2minute method was implemented as the core framework for prescribing training for elite Australian rowers throughout the 2009–2012 Olympic cycle. Results: The implementation of the T2minute method successfully established consistency with training prescription and monitoring practices within the NRCE high performance program. The national roll out this method has influenced rowing training methodology at elite and sub-elite levels in Australia. Since implementation, the method has undergone scientific validation. Further research is underway, utilising the method to explore complex relationships between rowers’ training and performance outcomes. Conclusion: The T2minute method is a novel approach that allows rowing coaches and sport scientists to utilise one consistent system to quantify load from varied training. Its implementation represents a considerable achievement in establishing a common framework for managing the training process within a complex organisational structure. This collaborative approach used to develop the T2minute method provides unique insight into the important considerations and practical challenges of applying training science to enhance elite sport performance.

We examined whether lung inflammatory mediators are increased during exercise and whether pharmacological blockade can prevent exercise-induced arterial hypoxemia (EIAH) in young athletes. Seventeen healthy athletes (9 men, 8 women; age 23 ± 3 yr) with varying degrees of EIAH completed maximal incremental treadmill exercise tests after administration of fexofenadine, zileuton, and nedocromil sodium or placebo in a randomized double-blind crossover study. Lung function, arterial blood gases, and inflammatory metabolites in plasma, urine, and induced sputum were assessed. Drug administration did not improve EIAH or gas exchange during exercise. At maximal exercise, oxygen saturation fell to 91.4 ± 2.6% (drug trial) and 91.9 ± 2.1% (placebo trial) and alveolar-arterial oxygen difference widened to 28.1 ± 6.3 Torr (drug trial) and 29.3 ± 5.7 Torr (placebo trial). Oxygen consumption, ventilation, and other exercise variables were similarly unaffected by drug treatment. Although plasma histamine increased with exercise, values did not differ between trials, and urinary leukotriene E4and 11β-prostaglandin F2αlevels were unchanged after exercise. Postexercise sputum revealed no significant changes in markers of inflammation. These results demonstrate that EIAH in young athletes is not attenuated with acute administration of drugs targeting histamine and bioactive lipids. We conclude that airway inflammation is of insufficient magnitude to cause impairments in gas exchange and does not appear to be linked to EIAH in healthy young athletes.

The causes of exercise-induced hypoxemia (EIH) remain unclear. We studied the mechanisms of EIH in highly trained cyclists. Five subjects had no significant change from resting arterial[Formula: see text]([Formula: see text]; 92.1 ± 2.6 Torr) during maximal exercise (C), and seven subjects (E) had a >10-Torr reduction in [Formula: see text] (81.7 ± 4.5 Torr). Later, they were studied at rest and during various exercise intensities by using the multiple inert gas elimination technique in normoxia and hypoxia (13.2% O2). During normoxia at 90% peak O2 consumption,[Formula: see text] was lower in E compared with C (87 ± 4 vs. 97 ± 6 Torr, P < 0.001) and alveolar-to-arterial O2tension difference (a-[Formula: see text]) was greater (33 ± 4 vs. 23 ± 1 Torr, P < 0.001). Diffusion limitation accounted for 23 (E) and 13 Torr (C) of thea-[Formula: see text]( P < 0.01). There were no significant differences between groups in arterial[Formula: see text]([Formula: see text]) or ventilation-perfusion (V˙a/Q˙) inequality as measured by the log SD of the perfusion distribution (logSDQ˙). Stepwise multiple linear regression revealed that lung O2 diffusing capacity ([Formula: see text]), logSDQ˙, and[Formula: see text] each accounted for ∼30% of the variance in [Formula: see text]( r = 0.95, P < 0.001). These data suggest that EIH has a multifactorial etiology related to[Formula: see text],V˙a/Q˙inequality, and ventilation.

wiring equipment and responses were recorded during the first over of each stage. Results: Sprint times increased significantly (p