The effect of overnight sleep deprivation after competitive rugby league matches on postmatch physiological and perceptual recovery.

PURPOSE: This study examined the effects of overnight sleep deprivation on recovery after competitive rugby league matches. METHODS: Eleven male amateur rugby league players played 2 competitive matches, followed by either a normal night's sleep (~8 h; CONT) or a sleep-deprived night (~0 h; SDEP) in a randomized fashion. Testing was conducted the morning of the match, immediately postmatch, 2 h postmatch, and the next morning (16 h postmatch). Measures included countermovement-jump (CMJ) distance, knee-extensor maximal voluntary contraction (MVC) and voluntary activation (VA), venous-blood creatine kinase (CK) and C-reactive protein (CRP), perceived muscle soreness, and a word-color recognition cognitive-function test. Percent change between postmatch and 16-h postmatch was reported to determine the effect of the intervention the next morning. RESULTS: Large effects indicated a greater postmatch to 16-h-postmatch percentage decline in CMJ distance after SDEP than in CONT (P = .10-.16, d = 0.95-1.05). Similarly, the percentage decline in incongruent word-color reaction times was increased in SDEP trials (P = .007, d = 1.75). Measures of MVC did not differ between conditions (P = .40-.75, d = 0.13-0.33), although trends for larger percentage decline in VA were detected in SDEP (P = .19, d = 0.84). Furthermore, large effects indicated higher CK and CRP responses 16 h postmatch in SDEP than in CONT (P = .11-.87, d = 0.80-0.88). CONCLUSIONS: Sleep deprivation negatively affected recovery after a rugby league match, specifically impairing CMJ distance and cognitive function. Practitioners should promote adequate postmatch sleep patterns or adjust training demands the next day to accommodate the altered physical and cognitive state after sleep deprivation.

The effect of post-match alcohol ingestion on recovery from competitive rugby league matches.

This study investigated the effects of alcohol ingestion on lower-body strength and power and physiological and cognitive recovery after competitive Rugby League matches. Nine male Rugby players participated in 2 matches, followed by 1 of 2 randomized interventions, a control or alcohol ingestion session. Four hours post-match, participants consumed either beverages containing a total of 1 g of ethanol per kilogram bodyweight (vodka and orange juice; ALC) or a caloric and taste-matched nonalcoholic beverage (orange juice; CONT). Before the match, immediately post-match, 2 hours post-, and 16 hours post-match measures of countermovement jump (CMJ); maximal voluntary contraction (MVC); voluntary activation (VA); and damage and stress markers of creatine kinase (CK), C-reactive protein (CRP), cortisol, and testosterone analyzed from venous blood collection; and cognitive function (modified Stroop test) were determined. Alcohol resulted in large effects for decreased CMJ height (-2.35 ± 8.14% and -10.53 ± 8.36% decrement for CONT and ALC, respectively; p = 0.15, d = 1.40), without changes in MVC (p = 0.52, d = 0.70) or VA (p = 0.15, d = 0.69). Furthermore, alcohol resulted in a significant slowing of total time in a cognitive test (p = 0.04, d = 1.59) while exhibiting large effects for detriments in congruent reaction time (p = 0.19, d = 1.73). Despite large effects for increased cortisol after alcohol ingestion during recovery (p = 0.28, d = 1.44), post-match alcohol consumption did not unduly affect testosterone (p = 0.96, d = 0.10), CK (p = 0.66, d = 0.70), or CRP (p = 0.75, d = 0.60). It seems that alcohol consumption during the evening after competitive rugby matches may have some detrimental effects on peak power and cognitive recovery the morning after a Rugby League match. Accordingly, practitioners should be aware of the potential associated detrimental effects of alcohol consumption on recovery and provide alcohol awareness to athletes at post-match functions.

Post-match changes in neuromuscular function and the relationship to match demands in amateur rugby league matches.

OBJECTIVES: The current study investigated the change in neuromuscular contractile properties following competitive rugby league matches and the relationship with physical match demands. DESIGN: Eleven trained, male rugby league players participated in 2-3 amateur, competitive matches (n = 30). METHODS: Prior to, immediately (within 15-min) and 2h post-match, players performed repeated counter-movement jumps (CMJ) followed by isometric tests on the right knee extensors for maximal voluntary contraction (MVC), voluntary activation (VA) and evoked twitch contractile properties of peak twitch force (Pt), rate of torque development (RTD), contraction duration (CD) and relaxation rate (RR). During each match, players wore 1 Hz Global Positioning Satellite devices to record distance and speeds of matches. Further, matches were filmed and underwent notational analysis for number of total body collisions. RESULTS: Total, high-intensity, very-high intensity distances covered and mean speed were 5585 ± 1078 m, 661 ± 265, 216 ± 121 m and 75 ± 14 m min(-1), respectively. MVC was significantly reduced immediately and 2h post-match by 8 ± 11 and 12 ± 13% from pre-match (p<0.05). Moreover, twitch contractile properties indicated a suppression of Pt, RTD and RR immediately post-match (p<0.05). However, VA was not significantly altered from pre-match (90 ± 9%), immediately-post (89 ± 9%) or 2h post (89 ± 8%), (p>0.05). Correlation analyses indicated that total playing time (r = -0.50) and mean speed (r = -0.40) were moderately associated to the change in post-match MVC, while mean speed (r = 0.35) was moderately associated to VA. CONCLUSIONS: The present study highlights the physical demands of competitive amateur rugby league result in interruption of peripheral contractile function, and post-match voluntary torque suppression may be associated with match playing time and mean speeds.