Effect of Training/Competition Load and Scheduling on Sleep Characteristics in Professional Rugby League Athletes.

ABSTRACT: Conlan, G, McLean, B, Kemp, J, and Duffield, R. Effect of training/competition load and scheduling on sleep characteristics in professional rugby league athletes. J Strength Cond Res 36(12): 3390-3397, 2022-This study examined the effect of training/competition load, scheduling, and associated factors on sleep behavior in professional rugby league athletes. Sleep characteristics were assessed in 26 professional rugby league athletes using wrist-mounted actigraphy and nightly sleep diaries. Sleep actigraphy assessed the time into and out of bed, the duration in bed, sleep duration, efficiency, latency, wake after sleep onset, number of awakenings, and the awakening length. Sleep was measured during 3 different weeks: (a) preseason low training load (TL) (2,356 ± 322 AU), (b) preseason high TL (3,542 ± 445 AU), and (c) in-season match week (1,526 ± 409 AU). The influences of internal TL (session rating of perceived exertion load), training schedule, age, and training location on sleep behavior were analyzed. Repeated-measures 2-way analysis of variance and effect size analyses (d) compared sleep variables between training weeks. The mean weekly sleep duration was significantly lower during high TL week (5 hours 53minutes ± 14 min/night; p = 0.015, d = 0.59) compared with the low TL (6 hours 25minutes ± 8 min·night -1 ) or match weeks (6 hours 26minutes ± 10 min·night -1 ; p = 0.02, d = 2.04). Reduced sleep duration in the high TL week occurred alongside earlier out-of-bed times compared with the low TL ( p = 0.003, d = 1.46) and match weeks ( p = 0.001, d = 5.99). Regardless, the lowest sleep duration was on match night ( p = 0.0001, d = 1.22). Earlier training start times resulted in earlier wake times ( p = 0.003, d = 4.84), shorter in-bed durations ( p = 0.0001, d = 0.62), and shorter sleep durations ( p = 0.002, d = 0.32). Younger athletes slept for longer durations ( p = 0.029, d = 1.70) and perceived their sleep quality to be superior ( p = 0.006, d = 14.94) compared with older athletes. Sleep attained by rugby league athletes is influenced by training and competition schedules, with early training start times and late-night matches being primary drivers of sleep behavior. Coaching staff should have awareness surrounding the implications of training and playing schedules on athlete sleeping patterns.

Match High-Speed Running Distances Are Often Suppressed After Return From Hamstring Strain Injury in Professional Footballers.

BACKGROUND: High-speed running is commonly implicated in the genesis of hamstring injury. The success of hamstring injury management is typically quantified by the duration of time loss or reinjury rate. These metrics do not consider any loss in performance after returning to play from hamstring injury. It is not known to what extent high-speed running is altered on return to play after such injury. HYPOTHESIS: Match high-speed running distance will change after returning from hamstring injury. STUDY DESIGN: Non-randomized cohort. LEVEL OF EVIDENCE: Level 3. METHODS: Match high-speed running distance in highest level professional football (soccer, Rugby League, Rugby Union, and Australian Rules) were examined for a minimum of 5 games prior and subsequent to hamstring strain injury for individual differences using a linear regression models approach. A total of 22 injuries in 15 players were available for analysis. RESULTS: Preinjury cumulative high-speed running distances were strongly correlated for each individual (r2 = 0.92-1.0; P < 0.0001). Pre- and postinjury high-speed running data were available for a median of 15 matches (range, 6-15). Variance from the preinjury high-speed running distance was significantly less (P = 0.0005) than the post injury values suggesting a suppression of high-speed running distance after returning from injury. On return to play, 7 of the 15 players showed a sustained absolute reduction in preinjury high-speed running distance, 7 showed no change, and 1 player (only) showed an increase. Analysis of subsequent (second and third injury) return to play showed no differences to return from the index injury. CONCLUSION: Return to play was not associated with return to high-speed running performance for nearly half of the players examined, although the same number showed no difference. Persisting deficits in match high-speed running may exist for many players after hamstring strain injury. CLINICAL RELEVANCE: Returning to play does not mean returning to (high-speed running) performance for nearly half of the high-level professional football players examined in this study. This suggests that successful return to play metrics should be expanded from simple time taken and recurrence to include performance.

The Fit Matters: Influence of Accelerometer Fitting and Training Drill Demands on Load Measures in Rugby League Players.

PURPOSE: To determine the relationship between drill type and accelerometer-derived loads during various team-sport activities and examine the influence of unit fitting on these loads. METHODS: Sixteen rugby league players were fitted with microtechnology devices in either manufacturer vests or playing jerseys before completing standardized running, agility, and tackling drills. Two-dimensional (2D) and 3-dimensional (3D) accelerometer loads (BodyLoad™) per kilometer were compared across drills and fittings (ie, vest and jersey). RESULTS: When fitted in a vest, 2D BodyLoad was higher during tackling (21.5 [14.8] AU/km) than during running (9.5 [2.5] AU/km) and agility (10.3 [2.7] AU/km). Jersey fitting resulted in more than 2-fold higher BodyLoad during running (2D = 9.5 [2.7] vs 29.3 [14.8] AU/km, 3D = 48.5 [14.8] vs 111.5 [45.4] AU/km) and agility (2D = 10.3 [2.7] vs 21.0 [8.1] AU/km, 3D = 40.4 [13.6] vs 77.7 [26.8] AU/km) compared with a vest fitting. Jersey fitting also produced higher BodyLoad during tackling drills (2D = 21.5 [14.8] vs 27.8 [18.6] AU/km, 3D = 42.0 [21.4] vs 63.2 [33.1] AU/km). CONCLUSIONS: This study provides evidence supporting the construct validity of 2D BodyLoad for assessing collision/tackling load in rugby league training drills. Conversely, the large values obtained from 3D BodyLoad (which includes the vertical load vector) appear to mask small increases in load during tackling drills, rendering 3D BodyLoad insensitive to changes in contact load. Unit fitting has a large influence on accumulated accelerometer loads during all drills, which is likely related to greater incidental unit movement when units are fitted in jerseys. Therefore, it is recommended that athletes wear microtechnology units in manufacturer-provided vests to provide valid and reliable information.