Karine Schaal

Low energy availability (EA) suppresses many physiological processes, including ovarian function in female athletes. Low EA could also predispose athletes to develop a state of overreaching. This study compared the changes in ad libitum energy intake (EI), exercise energy expenditure (ExEE), and EA among runners completing a training overload (TO) phase. We tested the hypothesis that runners becoming overreached would show decreased EA, suppressed ovarian function and plasma leptin, compared to well-adapted (WA) runners. After 1 menstrual cycle (baseline), 16 eumenorrheic runners performed 4 weeks of TO followed by a 2-week recovery (131±3% and 63±6% of baseline running volume respectively). Seven-day ExEE, EI, running performance (RUNPERF) and plasma [leptin] were assessed for each phase. Salivary [estradiol] was measured daily. Urinary [luteinizing hormone] tests confirmed ovulation. Nine runners adapted positively to TO (WA,ΔRUNPERF: +4±2%); seven were non-functionally overreached (NFOR, ΔRUNPERF -9±2%) as RUNPERF remained suppressed after the recovery period. WA increased EI during TO, maintaining their baseline EA despite a large increase in ExEE (ΔEA=+1.9±1.3 kcal.kgFFM-1.d-1, P=0.17). By contrast, NFOR showed no change in EI, leading to decreased EA (ΔEA=-5.6±2.1 kcal.kgFFM-1.d-1, P=0.04). [Leptin]b, mid-cycle and luteal [estradiol]s decreased in NFOR only. Contrasting with WA, NFOR failed to maintain baseline EA during TO, resulting in poor performance outcomes and suppressed ovarian function.NCT02224976. NOVELTY BULLETS: -Runners adapting positively to training overload (TO) increased ad libitum energy intake, maintaining baseline EA and ovarian function through TO. -By contrast, NFOR runners failed to increase energy intake, showing suppressed EA and ovarian function during TO.

Elite synchronized swimmers follow high-volume training regimen that result in elevated rates of exercise energy expenditure (ExEE). While adequate energy intake (EI) is important to optimize recovery, a number of sport-specific constraints may lead to chronically low energy availability (EA = EI-ExEE). This study aimed to quantify changes in EA, endocrine markers of energy conservation, and perceived fatigue in synchronized swimmers, during a week of baseline training followed by 4 weeks of intensified training (IT). EI, ExEE, and body composition were measured in nine swimmers at Baseline, midpoint (IT ), and end of IT (IT ). Waking saliva samples were obtained to measure [leptin] , [ghrelin] , and [cortisol] . Fatigue ratings were provided daily. ExEE increased by 27% during IT. Swimmers increased EI from Baseline to IT , but decreased it significantly from IT to IT . EA, fat mass, and [leptin] decreased from Baseline to IT , while [ghrelin] increased significantly. Fatigue at IT was inversely correlated with Baseline EI and EA. The significant decrease in EA was accompanied by endocrine signs of energy conservation in elite swimmers. As perceived fatigue was associated with low EA, particular attention should be paid to these athletes' energy intake during phases of heavy training.

Elite athletes frequently undergo periods of intensified training (IT) within their normal training program. These periods can lead athletes into functional overreaching, characterized by high perceived fatigue, impaired sleep, and performance. Because whole-body cryostimulation (WBC) has been proven to be an effective recovery method in the short term (<76 h), we investigated whether daily WBC sessions during IT could prevent exercise and sleep-related signs of overreaching. After a normal training week (BASE), 10 elite synchronized swimmers performed two 2-wk IT periods in a randomized crossover fashion using WBC daily (ITWBC) or not (ITCON), separated by 9 d of light training. Swim time trials (400 m) were performed at BASE and after each IT to quantify blood lactate ([La]B), HR (HR400), salivary alpha amylase ([α-amylase]s400), and cortisol ([cortisol]s400) responses. Swimmers wore a wrist actigraph nightly to monitor sleep patterns. Swim speed (400 m), [La]B400, and [α-amylase]s400 decreased from BASE to ITCON, although no significant changes were found after ITWBC. Decreased swim speed was correlated to decreased HR400 and [cortisol]s400. During ITCON, significant decreases in actual sleep duration (-21 ± 7 min) and sleep efficiency (-1.9% ± 0.8%) were observed, with increased sleep latency (+11 ± 5 min) and fatigue compared with BASE, although these variables did not change during ITWBC. Using a qualitative statistical analysis, we observed that daily WBC use resulted in a 98%, 59%, 66%, and 78% chance of preserving these respective variables compared with ITCON. WBC use during IT helped mitigate the signs of functional overreaching observed during ITCON, such as reduced sleep quantity, increased fatigue, and impaired exercise capacity. These results support the daily use of WBC by athletes seeking to avoid functional overreaching during key periods of competition preparation.