Effects of sleep hygiene and artificial bright light interventions on recovery from simulated international air travel.

PURPOSE: Despite the reported detrimental effects of international air travel on physical performance, a paucity of interventions have been scientifically tested and confirmed to benefit travelling athletes. Consequently, the aim of the present study was to examine the effects of sleep hygiene and artificial bright light interventions on physical performance following simulated international travel. METHODS: In a randomized crossover design, 13 physically active males completed 24 h of simulated international travel with (INT) and without (CON) the interventions. The mild hypoxia and cramped conditions typically encountered during commercial air travel were simulated in a normobaric, hypoxic room. Physical performance, subjective jet-lag symptoms and mood states were assessed in the morning and evening on the day prior to and for two days post-travel. Sleep quantity and quality were monitored throughout each trial. RESULTS: Sleep duration was significantly reduced during travel in both trials (P < 0.01), though total sleep duration during and following travel was almost significantly greater (P = 0.06) in INT (17.0 (16.2-17.8) h) compared to CON (15.7 (14.9-16.5) h). Maximal-sprint and countermovement jump (P < 0.05), but not Yo-Yo Intermittent Recovery level 1 test (P > 0.05) performance, were significantly reduced the evening of day 1 and 2 post-travel, with no differences between trials (P > 0.05). Furthermore, vigour was significantly greater (P = 0.04) the morning of day 2 in INT [5.3 (3.9-6.7)] compared to CON [2.8 (1.4-4.2)], and subjective jet-lag symptoms and mood states were significantly worse on day 2 in CON only (P < 0.05). CONCLUSIONS: Whilst reducing travel-induced sleep disruption may attenuate travel fatigue, no improvements in the recovery of physical performance were apparent.

Effect of hydrotherapy on the signs and symptoms of delayed onset muscle soreness.

This study independently examined the effects of three hydrotherapy interventions on the physiological and functional symptoms of delayed onset muscle soreness (DOMS). Strength trained males (n = 38) completed two experimental trials separated by 8 months in a randomised crossover design; one trial involved passive recovery (PAS, control), the other a specific hydrotherapy protocol for 72 h post-exercise; either: (1) cold water immersion (CWI: n = 12), (2) hot water immersion (HWI: n = 11) or (3) contrast water therapy (CWT: n = 15). For each trial, subjects performed a DOMS-inducing leg press protocol followed by PAS or one of the hydrotherapy interventions for 14 min. Weighted squat jump, isometric squat, perceived pain, thigh girths and blood variables were measured prior to, immediately after, and at 24, 48 and 72 h post-exercise. Squat jump performance and isometric force recovery were significantly enhanced (P < 0.05) at 24, 48 and 72 h post-exercise following CWT and at 48 and 72 h post-exercise following CWI when compared to PAS. Isometric force recovery was also greater (P < 0.05) at 24, 48, and 72 h post-exercise following HWI when compared to PAS. Perceived pain improved (P < 0.01) following CWT at 24, 48 and 72 h post-exercise. Overall, CWI and CWT were found to be effective in reducing the physiological and functional deficits associated with DOMS, including improved recovery of isometric force and dynamic power and a reduction in localised oedema. While HWI was effective in the recovery of isometric force, it was ineffective for recovery of all other markers compared to PAS.

The effect of contrast water therapy on symptoms of delayed onset muscle soreness.

This study examined the effect of contrast water therapy (CWT) on the physiological and functional symptoms of delayed onset muscle soreness (DOMS) following DOMS-inducing leg press exercise. Thirteen recreational athletes performed 2 experimental trials separated by 6 weeks in a randomized crossover design. On each occasion, subjects performed a DOMS-inducing leg press protocol consisting of 5 x 10 eccentric contractions (180 seconds recovery between sets) at 140% of 1 repetition maximum (1RM). This was followed by a 15-minute recovery period incorporating either CWT or no intervention, passive recovery (PAS). Creatine kinase concentration (CK), perceived pain, thigh volume, isometric squat strength, and weighted jump squat performance were measured prior to the eccentric exercise, immediately post recovery, and 24, 48, and 72 hours post recovery. Isometric force production was not reduced below baseline measures throughout the 72-hour data collection period following CWT ( approximately 4-10%). However, following PAS, isometric force production (mean +/- SD) was 14.8 +/- 11.4% below baseline immediately post recovery (p < 0.05), 20.8 +/- 15.6% 24 hours post recovery (p < 0.05), and 22.5 +/- 12.3% 48 hours post recovery (p < 0.05). Peak power produced during the jump squat was significantly reduced (p < 0.05) following both PAS (20.9 +/- 13.4%) and CWT (12.8 +/- 8.0%), with the mean reduction in power for PAS being marginally (not significantly) greater than for CWT (effect size = 0.76). Thigh volume measured immediately following CWT was significantly less than PAS. No significant differences in the changes in CK were found; in addition, there were no significant (p > 0.01) differences in perceived pain between treatments. Contrast water therapy was associated with a smaller reduction, and faster restoration, of strength and power measured by isometric force and jump squat production following DOMS-inducing leg press exercise when compared to PAS. Therefore, CWT seems to be effective in reducing and improving the recovery of functional deficiencies that result from DOMS, as opposed to passive recovery.