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We sought to describe cerebrovascular responses to incremental exercise and test the hypothesis that changes in cerebral oxygenation influence maximal performance. Eleven men cycled in three conditions: 1) sea level (SL); 2) acute hypoxia [AH; hypobaric chamber, inspired [Po.sub.2] ([Pi.sub.o.sub.2]) 86 Torr]; and 3) chronic hypoxia [CH; 4,300 m, [Pi.sub.o.sub.2], 86 Torr]. At maximal work rate ([W.sub.max]), fraction of inspired oxygen ([Fi.sub.o.sub.2]) was surreptitiously increased to 0.60, while subjects were encouraged to continue pedaling. Changes in cerebral (frontal lobe) ([C.sub.ox]) and muscle (vastus lateralis) oxygenation ([M.sub.ox]) (near infrared spectroscopy), middle cerebral artery blood flow velocity (MCA [V.sub.mean]; transcranial Doppler), and end-tidal [Pco.sub.2] ([Pet.sub.co.sub.2]) were analyzed across % [W.sub.max] (significance at P < 0.05). At SL, [Pet.sub.co.sub.2], MCA [V.sub.mean], and [C.sub.ox] fell as work rate rose from 75 to 100% [W.sub.max]. During AH, [Pet.sub.co.sub.2] and MCA [V.sub.mean], declined from 50 to 100% [W.sub.max], while [C.sub.ox] fell from rest. With CH, [Pet.sub.co.sub.2] and [C.sub.ox] dropped throughout exercise, while MCA [V.sub.mean] fell only from 75 to 100% [W.sub.max]. [M.sub.ox] fell from rest to 75% [W.sub.max] at SL and AH and throughout exercise in CH. The magnitude of fall in [C.sub.ox], but not [M.sub.ox], was different between conditions (CH > AH > SL). [Fi.sub.o.sub.2] 0.60 at [W.sub.max] did not prolong exercise at SL, yet allowed subjects to continue for 96 [+ or -] 61 s in AH and 162 [+ or -] 90 s in CH. During [Fi.sub.o.sub.2] 0.60, [C.sub.ox] rose and [M.sub.ox] remained constant as work rate increased. Thus cerebral hypoxia appeared to impose a limit to maximal exercise during hypobaric hypoxia ([Pi.sub.o.sub.2] 86 Torr), since its reversal was associated with improved performance. altitude; near infrared spectroscopy; cerebral blood flow; fatigue; muscle oxygenation

Disordered eating behaviors are typically seen as a problem in females and there are little data assessing their prevalence in males. The objective of the present cross-sectional investigation was to identify subclinical disordered eating patterns and dietary characteristics among competitive male cyclists. A nutritional questionnaire, the Eating Attitudes Test-26 (EAT-26), and Survey of Eating Disorders Among Cyclists, were completed by male cyclists (n=61) and noncyclists (n=63). Male cyclists scored significantly higher on the EAT-26 compared to the male control group (P<0.001). Of the 12 cyclists who showed the greatest tendency toward disordered eating (EAT-26>20), only five self-reported having an eating disorder. Approximately half the cyclists believed eating disorders were somewhat common in the sport (28 of 60). The nutritional questionnaire revealed that male cyclists may not consume adequate nutrients to sustain their metabolic needs. Thus, the results of this study suggest that male cyclists may not know how to identify disordered eating habits and may be at an amplified risk for eating disorders and nutritional deficits. Further research should utilize various measures to address the prevalence of disordered eating in a larger sample size and quantify energy balance.

This article examines antioxidant levels and evidence of damage from oxidative stress in members of an elite men's Alpine ski team during summer training. Findings indicate that ten days of intense training does not elevate indicators of oxidative stress but can result in declines in antioxidant levels.

New Findings: What is the central question of this study?Does the combination of methazolamide and theophylline reduce symptoms of acute mountain sickness (AMS) and improve aerobic performance in acute hypobaric hypoxia?What is the main finding and its importance?The oral combination of methazolamide (100 BID) and theophylline (300 BID) improved arterial oxygen saturation but did not reduce symptoms of AMS and impaired aerobic performance. We do not recommend this combination of drugs for prophylaxis against the acute negative effects of hypobaric hypoxia. A limited number of small studies have suggested that methazolamide and theophylline can independently reduce symptoms of acute mountain sickness (AMS) and, if taken together, can improve aerobic exercise performance in normobaric hypoxia. We performed a randomized, double‐blind, placebo‐controlled, cross‐over study to determine if the combination of oral methazolamide and theophylline could provide prophylaxis against AMS and improve aerobic performance in hypobaric hypoxia (∼4875 m). Volunteers with histories of AMS were screened at low altitude (1650 m) and started combined methazolamide (100 mg BID) and theophylline (300 mg BID) treatment, or placebo, 72 h prior to decompression. Baseline AMS (Lake Louise Questionnaire), blood (haemoglobin, haematocrit), cognitive function, ventilatory and pulse oximetry (SpO2) measures were assessed at low altitude and repeated between 4 and 10 h of exposure to hypobaric hypoxia (PB = 425 mmHg). Aerobic exercise performance was assessed during a 12.5 km cycling time trial (TT) after 4 h of hypobaric hypoxia. Subjects repeated all experimental procedures after a 3‐week washout period. Differences between drug and placebo trials were evaluated using repeated measures ANOVA (α = 0.05). The drugs improved resting SpO2 by ∼4% (P < 0.01), but did not affect the incidence or severity of AMS or cognitive function scores relative to placebo. Subjects' performance on the 12.5 km TT was ∼3% worse when taking the drugs (P < 0.01). The combination of methazolamide and theophylline in the prescribed dosages is not recommended for use at high altitude as it appears to have no measurable effect on AMS and can impair aerobic performance. [ABSTRACT FROM AUTHOR]

The purpose of this study was to assess the effects of purified oxygenated water on exercise performance under hypoxic conditions. Nine recreational male cyclists (age = 26.6 ± 5.2 y, weight = 87.6 ± 19.5 kg, VO2peak = 46.5 ± 5.9 mL · kg-1 · min-1) completed two 600 kJ cycling time trials under hypoxic conditions (FIO2 = 13.6% O2, Pbar = 641 mmHg) separated by 2 wk. Trials were completed following 3 d ingestion of 35 mL · kg-1 · d-1 of control (CON) or experimental (EXP) water. Time to completion, heart rate (HR), rate of perceived exertion (RPE), pulse oximetry (SaO2), blood gases (PcO2 and PcCO2), and lactate were measured during the trials. Hydration was assessed with pre- and post-exercise body weight and 24-h urine specific gravity. Performance, hydration, and blood oxygenation were unaffected by EXP water. Results of this study suggest that purified oxygenated water does not improve exercise performance in moderately active males. [ABSTRACT FROM AUTHOR]