Neuromuscular, biochemical and perceptual post-match fatigue in professional rugby league forwards and backs

Abstract

In this study, we investigated changes in creatine kinase, perceptual and neuromuscular fatigue of professional rugby league players after match-play. Twenty-three male rugby league players (10 backs, 13 forwards) had their creatine kinase, perceptual ratings of fatigue, attitude to training, muscle soreness, and flight time in a countermovement jump measured before and 1 and 2 days after (day 1 and day 2 respectively) league matches. Total playing time, offensive and defensive contacts were also recorded for each player. Creatine kinase was higher both 1 and 2 days after than before matches (P < 0.05) in forwards and backs. Similarly, perceived fatigue and muscle soreness were higher than pre-match on both days 1 and 2 (P < 0.05), but did not differ between groups (P > 0.05). Jump performance was lower on day 1 but not day 2 for both groups (P < 0.05). While total playing time was longer in backs (P < 0.05), relative frequencies for all contacts were greater in forwards (P < 0.05). Contacts for forwards were correlated with all markers of fatigue (P < 0.05), but only flight time was correlated with offensive contacts in backs (P < 0.05). Despite the mechanisms of fatigue being different between forwards and backs, our results highlight the multidimensional nature of fatigue after a rugby league match and that these markers do not differ between positions.

Countermovement Jump Performance Is Not Affected During an In-Season Training Microcycle in Elite Youth Soccer Players

“…Previous studies using such protocols have reported impaired jump performance following competitive match-play in Australian football 3,5 , rugby league 4 and soccer 2,6,7 . Although it is important to quantify jump performance following an acute bout of activity (such as a competitive match), it is also of interest to investigate the response to multiple bouts of exercise (such as training regimens).…”

“…Measures of neuromuscular status in team sports in the applied setting have previously included various vertical jumps such as the countermovement jump (CMJ) and the squat jump (SJ) 2,3,4 .…”

Understanding the Fatigue-Recovery Cycle in Team Sport Athletes

“…Blood and salivary markers have been used to examine the possible mechanisms associated with neuromuscular and perceptual fatigue following team sport competition [7,14,16]. Although testing samples can be expensive, changes in biochemical, hormonal and immunological measures can be easily assessed around daily training activities with non-invasive blood capillary samples and salivary swabs.…”

“…There are a number of questionnaires that have been used in the literature such as the POMS, RESTQ-Sport and DALDA questionnaires [8,18]. Studies have shown alterations in perceptual fatigue to be more sensitive to tournament competition than jumpderived measures of neuromuscular fatigue [1] and perceived fatigue and muscle soreness are known to outlast suppressed neuromuscular function and biochemical markers following rugby league matches [14]. Increases in perceptual fatigue are suggested to alter an athlete's sense of effort and force them to down-regulate their exercise capacity [19].…”

“…Measures of both upper-and lower-body neuromuscular function such as mean power and force production, time to peak force and jump height and have shown acceptable reliability and day-to-day variability making them useful measures to assess fatigue over a training mesocycle or playing season [9][10][11]. Team sport athletes competing in contact sports such as rugby football can show severe reductions in both upper-and lower-body neuromuscular function following match-play suggested to be caused by reductions in contraction velocity associated with increased muscle damage [12][13][14]. Other studies examining neuromuscular fatigue in low or non-contact team sports have questioned the sensitivity of jumping-derived measures [1,15].…”