Variations in strength-speed-power performance across the season: do true changes occur in elite rugby players?

This study aimed to determine, through the use of a highly sensitive statistical tool, whether real changes in performance were present; and compare the rates of meaningful variations in strength, speed, and power parameters at different time-points during the competitive season in national team rugby players. Thirty-two players were assessed 5 times across the season using the following tests: squat jump and countermovement jump tests; 30-m sprint velocity; and one-repetition maximum (1RM) in the half-squat and bench-press exercises. A repeated-measures analysis of variance was conducted to test for differences between successive time-points. Individual coefficients of variation values were used to set target scores for post-measurements and examine whether changes in performance parameters were greater than the natural test variance, thus providing an indication of whether "true changes" occurred. No significant changes were detected in the vertical jump height, 1RM measures, and sprint velocity and momentum throughout the 11-month period (P > 0.05). True changes occurred much more frequently for strength-power measures than for sprint velocity and momentum. Elite rugby union players did not exhibit significant variations in neuromuscular performance across the competitive period, when a group-based analysis was conducted. However, at the individual level, "true changes" in strength-power-(but not in speed-) related qualities were consistently observed over the competitive season.

Carrying eggs uphill: are costs of reproduction stronger on steeper slopes?

Locomotor impairment during pregnancy is a well-documented cost of reproduction, but most empirical studies have not incorporated ecological complexity, such as locomotion on sloping inclines rather than horizontal surfaces. Biomechanical factors suggest that carrying a heavy burden-including shifts in the body's centre of mass-may impair locomotor ability even more when an animal is running uphill. If so, then measuring costs of reproduction on horizontal racetracks may underestimate these costs in nature for arboreal species. To evaluate this prediction, we measured the pregnancy-induced reduction in speed for jacky dragons (Amphibolurus muricatus) at inclines ranging from 0 to 45°. Both pregnancy and steeper slopes reduced lizard performance, but pregnancy did not exacerbate the locomotor decrement on steeper racetracks. An ability to maintain mobility on steep slopes during pregnancy may be a target of selection in arboreal taxa. To understand the evolutionary context of locomotion-based costs of reproduction, we also need studies on the relationship between organismal performance and ecologically relevant measures such as predation risk.

Effects of Multi-joint Eccentric Training on Muscle Function When Combined With Aquatic Plyometric Training: A Minimal Dose, Mixed Training Study.

OBJECTIVES: To examine the effects of a combined eccentric overload and aquatic-based plyometric training program on muscle function/performance measures and soreness versus an eccentric-only training protocol using a minimal dose training paradigm. METHODS: Twenty-five participants were randomized into either an eccentric-only training group (ECC) or a combined eccentric and aquatic plyometric group (ECC + AQP). The ECC group performed eccentric training once per week for 6-weeks while the ECC + AQP group performed the same eccentric training but with an additional aquatic plyometric training session. RESULTS: There was no group × trial interactions for any of the variables. However, the training elicited large improvements in eccentric strength in both ECC (27%; ES = 1.33) and ECC+AQP (17%; ES = .86) groups. Isometric strength improved moderately for ECC and ECC+AQP groups (17.2%, ES = .53;9%, ES = .45). A moderate increase was observed for depth jump height for both ECC and ECC+AQP groups (13.1%, ES = .48;8.8%, ES = .36). No changes were observed for countermovement jump or sprint time and muscle soreness did not differ between groups. CONCLUSIONS: Minimal dose multi-joint eccentric overload training improved strength and depth jump outcomes after 6-weeks regardless of the training condition but adding a minimal dose aquatic plyometric protocol does not improve muscle function-based outcomes.

Responses to artificial selection for locomotor activity: A focus on death feigning in red flour beetle.

Whole-organism performance, including locomotor activity, is an important fitness trait in many animals. Locomotor activity is often classified into sprint speed and locomotor endurance and differences in sprint speed and locomotor endurance affect on other traits such as life-history traits. Previous studies found that locomotor endurance, sprint speed and brain dopamine (DA) levels are correlated with artificial selection for death feigning (an anti-predator behaviour that we refer to as 'death-feigning syndrome') in some insect species. Thus, if the syndrome has a genetic basis, death feigning, sprint speed and brain DA levels may be affected by artificial selection for locomotor endurance. We artificially selected for locomotor endurance over 10 generations in the red flour beetle Tribolium castaneum, and established higher (H) and lower activity (L) strains, then compared their death-feigning behaviour, sprint speed and brain DA levels. H-strain beetles exhibited significantly shorter duration of death-feigning, and significantly higher sprint speeds, suggesting variation in death-feigning syndrome. Surprisingly, although brain DA expression affects various animal behaviours, we found no significant differences in the brain DA expressions of H- and L-strain beetles. Thus, our results imply genetic correlations between locomotor endurance, sprint speed and death feigning, but not with brain DA expression, suggesting that differences in the biogenic amine results of our and previous studies may reflect differences in behavioural expression mechanisms.

Colours of stress in male Indian rock agamas predict testosterone levels but not performance.

Rapid physiological colour change offers dynamic signalling opportunities that can reveal distinct information to receivers in different contexts. Information content in dynamic colours, however, is largely unexplored. In males of the Indian rock agama (Psammophilus dorsalis), stressful events, including male-male agonistic interactions, induce a colour change, wherein the dorsal band turns yellow and the lateral bands turn orange. We aimed to determine whether these pigment-based dynamic colours convey information about individual quality. Using an agamid-specific visual model, we first quantified the chromatic and achromatic contrasts of each colour component displayed by males during handling stress, which induces the maximal response of aggression-typical colours. We then measured baseline testosterone levels, morphology (body mass and size), and performance measures (bite force and sprint speed) of these lizards. Chromatic contrasts of the dorsal yellow and lateral orange bands, individually and relative to each other (internal pair), were negatively correlated with testosterone levels, while the chromatic contrast of the internal pair was positively correlated with body condition. The lack of an association between colour contrasts and both bite force and sprint speed indicate that the conspicuousness of colours expressed during stressful events, such as agonistic interactions, do not reveal male performance ability. Despite our expectations of a positive relationship with testosterone, morphology (body condition), and performance (bite force, sprint speed), we find that for P. dorsalis, the conspicuousness of stress-induced colours provide only some information about individual quality. We speculate that the dynamicity of physiological colours may influence their function as content-containing signals in social interactions.

The functional basis for variable antipredatory behavioral strategies in the chameleon Chamaeleo calyptratus.

To counterbalance demands of different selective pressures, many species possess morphological, physiological and behavioral specializations that increase survival in their environments. Predation is one such pressure that can elicit multiple adaptive responses, and the effectiveness of antipredator behaviors likely vary both by environment and individual across time. Chameleons use multiple antipredator strategies, many of which vary with body size and habitat type. Although their unique morphological and physiological traits produce relatively slow locomotion, which is poorly suited for fleeing, chameleons can also use crypsis or aggression to avoid predation. To examine the functional basis for variable antipredator behavioral responses, we subjected chameleons to a series of mock predation trials and determined how often individuals adopted each antipredator strategy, and then quantified the performance capacities underlying each strategy. In particular, we measured bite force as a determinant for aggression, sprint velocity for fleeing, and degree of color change for crypsis. We found that aggression was predicted by traits associated with higher absolute and relative bite force, as well as habitat type; fleeing was predicted by higher normalized sprint velocity and habitat type; and crypsis was predicted by habitat type, color change capacity in bird color space and the interaction between the two. These results illustrate the importance of considering both functional capacity and environmental context in antipredator behavior decision-making.

Comparison of the effects of velocity-based vs. traditional resistance training methods on adaptations in strength, power, and sprint speed: A systematic review, meta-analysis, and quality of evidence appraisal.

We estimated the effectiveness of using velocity feedback to regulate resistance training load on changes in muscle strength, power, and linear sprint speed in apparently healthy participants. Academic and grey literature databases were systematically searched to identify randomised trials that compared a velocity-based training intervention to a 'traditional' resistance training intervention that did not use velocity feedback. Standardised mean differences (SMDs) were pooled using a random effects model. Risk of bias was assessed with the Risk of Bias 2 tool and the quality of evidence was evaluated using the GRADE approach. Four trials met the eligibility criteria, comprising 27 effect estimates and 88 participants. The main analyses showed trivial differences and imprecise interval estimates for effects on muscle strength (SMD 0.06, 95% CI -0.51-0.63; I2 = 42.9%; 10 effects from 4 studies; low-quality evidence), power (SMD 0.11, 95% CI -0.28-0.49; I2 = 13.5%; 10 effects from 3 studies; low-quality evidence), and sprint speed (SMD -0.10, 95% CI -0.72-0.53; I2 = 30.0%; 7 effects from 2 studies; very low-quality evidence). The results were robust to various sensitivity analyses. In conclusion, there is currently no evidence that VBT and traditional resistance training methods lead to different alterations in muscle strength, power, or linear sprint speed.

Sexual selection on performance traits in an Australian lizard with alternative reproductive tactics.

Sexual selection shapes the adaptive landscape in complex ways that lead to trait integration. Much of our understanding of selection comes from studies of morphological traits. However, few studies attempt to quantify the form and direction of selection on performance even though it is predicted to be a more direct target of selection in nature. We measured sexual selection on performance traits (bite force, sprint speed and endurance) in an Australian lizard, the Eastern water skink (Eulamprus quoyii). We first staged 123 contests between size-matched males to investigate whether performance traits were important in determining contest outcome. In a second experiment, we established six breeding populations in large replicate semi-natural enclosures to estimate whether performance traits predicted reproductive success. Our results show that none of the performance measures were important in predicting contest outcome and were not generally strong predictors of reproductive success. However, our analyses suggest a complex fitness landscape driven by males adopting different alternative reproductive tactics (ARTs). We provide a rare test of the role performance plays in sexual selection and highlight the need to test common assumptions regarding the link between maximal performance and fitness. Our results suggest that performance traits may not necessarily be direct targets of sexual selection, but rather indirect targets through their integration with morphological and/or behavioural traits, highlighting a need for more explicit tests of the predicted links between performance and fitness.

Energy expenditure across immune challenge severities in a lizard: consequences for innate immunity, locomotor performance and oxidative status.

Reptiles, like other vertebrates, rely on immunity to defend themselves from infection. The energetic cost of an immune response is liable to scale with infection severity, prompting constraints on other self-maintenance traits if immune prioritization exceeds energy budget. In this study, adult male side-blotched lizards (Uta stansburiana) were injected with saline (control) or high (20 µg g-1 body mass) or low (10 µg g-1 body mass) concentrations of lipopolysaccharide (LPS) to simulate bacterial infections of discrete severities. The costs and consequences of the immune response were assessed through comparisons of change in resting metabolic rate (RMR), energy metabolites (glucose, glycerol, triglycerides), innate immunity (bactericidal ability), sprint speed and oxidative status (antioxidant capacity, reactive oxygen metabolites). High-LPS lizards had the lowest glucose levels and greatest sprint reductions, while their RMR and bactericidal ability were similar to those of control lizards. Low-LPS lizards had elevated RMR and bactericidal ability, but glucose levels and sprint speed changes between those of high-LPS and control lizards. Levels of glycerol, triglycerides, reactive oxygen metabolites and antioxidant capacity did not differ by treatment. Taken together, energy expenditure for the immune response varies in a non-linear fashion with challenge severity, posing consequences for performance and self-maintenance processes in a reptile.

Fast and dark: The case of Mezquite lizards at extreme altitude.

Sprint speed is a major performance trait in animal fitness involved in escaping from predators, obtaining food, and defending territory. Biotic and abiotic factors may influence sprint speed in lizards. Temperature decreases at higher altitude. Therefore, lizards at high elevations may require longer basking times to reach optimal body temperatures, increasing their vulnerability to predation and decreasing their time for other activities such as foraging or reproduction. Here, we tested whether the maximum sprint speed of a lizard that shows conservative thermal ecology varied along an altitudinal gradient comprising low (2500 m), middle (3400 m) and high-altitude (4300 m) populations. We also tested whether sprint speed was related to dorsal reflectance at different ecologically relevant temperatures. Given that the lizard Sceloporus grammicus shows conservative thermal ecology with altitude, we expected that overall average sprint speed would not vary with altitude. However, given that darker lizards heat up quicker, we expected that darker lizards would be faster than lighter lizards. Our results suggest that S. grammicus at high altitude are faster and darker at 30 °C, while lizards from low and middle altitude are faster and lighter in color at 20 °C than high altitude lizards. Also, our results suggest a positive relationship between sprint speed and dorsal skin reflectance at 10 and 20 °C. Sprint speed was also affected by snout-vent length, leg length, and leg thickness at 10 °C. These results suggest that, even though predation pressure is lower at extreme altitudes, other factors such as vegetation cover or foraging mode have influenced sprint speed.

Temporal variation in thermal plasticity in a free-ranging subalpine lizard.

Thermally variable environments are particularly challenging for ectotherms as physiological functions are thermo-dependent. As a consequence, ectotherms in highly seasonal environments are predicted to have greater thermal plasticity. However, much of our understanding of thermal plasticity comes from controlled experiments in a laboratory setting. Relatively fewer studies investigate thermal plasticity in free-ranging animals living in their natural environment. We investigated the presence of thermal plasticity within a single activity season in adult males of a natural high elevation population of White's skink (Liopholis whitii) in south-eastern Australia. This species lives in a permanent home site (rock crevice and/or burrow), facilitating the repeated capture of the same individuals across the activity season. We monitored the thermal variation across the field site and over the activity season, and tested thermal tolerances and performance of male L. whitii on three occasions across their activity season. Maximum and average temperatures varied across the field site, and temperatures gradually increased across the study period. Evidence of temporal plasticity was identified in the critical thermal minimum and thermal tolerance breadth, but not in the critical thermal maximum. Thermal performance was also found to be plastic, but no temporal patterns were evident. Our temporal plasticity results are consistent which much of the previous literature, but this is one of the first studies to identify these patterns in a free-ranging population. In addition, our results indicate that performance may be more plastic than previous literature suggests. Overall, our study highlights the need to pair laboratory and field studies in order to understand thermal plasticity in an ecologically relevant context.

Interacting effects of predation risk and resource level on escape speed of amphibian larvae along a latitudinal gradient.

Fast-growing genotypes living in time-constrained environments are often more prone to predation, suggesting that growth-predation risk trade-offs are important factors maintaining variation in growth along climatic gradients. However, the mechanisms underlying how fast growth increases predation-mediated mortality are not well understood. Here, we investigated if slow-growing, low-latitude individuals have faster escape swimming speed than fast-growing high-latitude individuals using common frog (Rana temporaria) tadpoles from eight populations collected along a 1500 km latitudinal gradient. We measured escape speed in terms of burst and endurance speeds in tadpoles raised in the laboratory at two food levels and in the presence and absence of a predator (Aeshna dragonfly larvae). We did not find any latitudinal trend in escape speed performance. In low food treatments, burst speed was higher in tadpoles reared with predators but did not differ between high-food treatments. Endurance speed, on the contrary, was lower in high-food tadpoles reared with predators and did not differ between treatments at low food levels. Tadpoles reared with predators showed inducible morphology (increased relative body size and tail depth), which had positive effects on speed endurance at low but not at high food levels. Burst speed was positively affected by tail length and tail muscle size in the absence of predators. Our results suggest that escape speed does not trade-off with fast growth along the latitudinal gradient in R. temporaria tadpoles. Instead, escape speed is a plastic trait and strongly influenced by the interaction between resource level and predation risk.

Improvement of Elite Female Athletes' Physical Performance With a 3-Week Unexpected Disturbance Program.

CONTEXT: Sensorimotor training is commonly used in a rehabilitative setting; however, the effectiveness of an unexpected disturbance program (UDP) to enhance performance measures in uninjured elite athletes is unknown. OBJECTIVE: To assess the impact of a 3-wk UDP program on strength, power, and proprioceptive measures. DESIGN: Matched-group, pre-post design. SETTING: National sport institute. PARTICIPANTS: 21 international-level female field hockey athletes. INTERVENTION: Two 45-min UDP sessions were incorporated into each week of a 3-wk training program (total 6 sessions). MAIN OUTCOME MEASURES: 1-repetition-maximum strength, lower-limb power, 20-m running speed, and proprioception tests were performed before and after the experimental period. RESULTS: Substantial improvements in running sprint speed at 5-m (4.4 ± 2.6%; effect size [ES]: 0.88), 10-m (2.1 ± 1.9%; ES: 0.51), and 20-m (1.0 ± 1.6%; ES: 0.23) were observed in the UDP group. Squat-jump performance was also clearly enhanced when compared to the control group (3.1 ± 6.1%; ES: 0.23). Small but clear improvements in maximal strength were observed in both groups. CONCLUSIONS: A 3-wk UDP can elicit clear enhancements in running sprint speed and concentric-only jump performance. These improvements are suggestive of enhanced explosive strength and are particularly notable given the elite training status of the cohort and relatively short duration of the intervention. Thus, the authors would reiterate the statement by Gruber et al (2004) that sensorimotor training is a "highly efficient" modality for improving explosive strength.

Thermal physiology: A new dimension of the pace-of-life syndrome.

Current syndrome research focuses primarily on behaviour with few incorporating components of physiology. One such syndrome is the pace-of-life syndrome (POLS) which describes covariation between behaviour, metabolism, immunity, hormonal response, and life-history traits. Despite the strong effect temperature has on behaviour, thermal physiology has yet to be considered within this syndrome framework. We proposed the POLS to be extended to include a new dimension, the cold-hot axis. Under this premise, it is predicted that thermal physiology and behaviour would covary, whereby individual positioning along the thermal continuum would coincide with that of the behavioural continuum. This hypothesis was tested by measuring thermal traits of delicate skinks (Lampropholis delicata) and linking it to their behaviour. Principal components analysis and structural equation modelling were used to determine if traits were structured within the POLS and to characterize the direction of their interactions. Model results supported the inclusion of the cold-hot axis into the POLS and indicated that thermal physiology was the driver of this relationship, in that thermal traits either constrained or promoted activity, exploration, boldness and social behaviour. This study highlights the need to integrate thermal physiology within a syndrome framework.

The effect of skin reflectance on thermal traits in a small heliothermic ectotherm.

Variation in colour patterning is prevalent among and within species. A number of theories have been proposed in explaining its evolution. Because solar radiation interacts with the pigmentation of the integument causing light to either be reflected or absorbed into the body, thermoregulation has been considered to be a primary selective agent, particularly among ectotherms. Accordingly, the colour-mediated thermoregulatory hypothesis states that darker individuals will heat faster and reach higher thermal equilibria while paler individuals will have the opposite traits. It was further predicted that dark colouration would promote slower cooling rates and higher thermal performance temperatures. To test these hypotheses we quantified the reflectance, selected body temperatures, performance optima, as well as heating and cooling rates of an ectothermic vertebrate, Lampropholis delicata. Our results indicated that colour had no influence on thermal physiology, as all thermal traits were uncorrelated with reflectance. We suggest that crypsis may instead be the stronger selective agent as it may have a more direct impact on fitness. Our study has improved our knowledge of the functional differences among individuals with different colour patterns, and the evolutionary significance of morphological variation within species.

Sprint sensitivity and locomotor trade-offs in green anole (Anolis carolinensis) lizards.

How well an organism completes an ecologically relevant task - its performance - is often considered a key factor in determining individual fitness. Historically, ecomorphological studies have examined how morphological traits determine individual performance in a static manner, assuming that differential fitness in a population is due indirectly to differences in morphological traits that determine a simple measure of performance. This assumption, however, ignores many ecological factors that can constrain performance in nature, such as substrate variation and individual behavior. We examined some of these complexities in the morphology-performance-fitness paradigm, primarily the impact that substrate variation has on performance. We measured maximal sprint speed of green anole lizards on four substrates that varied in size and complexity and are used by or available to individuals in nature. Performance decreased significantly from a broad substrate to a narrow substrate, and lizards were three times slower on a complex substrate than the broadest substrate. We also detected trade-offs in running on substrates with different diameters and in cluttered versus uncluttered environments. Furthermore, morphological predictors of performance varied among substrates. This indicates that natural selection may act on different morphological traits, depending on which substrates are used by individuals, as well as an individual's ability to cope with changes in substrate rather than maximal capacities.

Making Olympic lizards: the effects of specialised exercise training on performance.

Exercise training is well known to affect a suite of physiological and performance traits in mammals, but effects of training in other vertebrate tetrapod groups have been inconsistent. We examined performance and physiological differences among green anole lizards (Anolis carolinensis) that were trained for sprinting or endurance, using an increasingly rigorous training regimen over 8 weeks. Lizards trained for endurance had significantly higher post-training endurance capacity compared with the other treatment groups, but groups did not show post-training differences in sprint speed. Although acclimation to the laboratory environment and training explain some of our results, mechanistic explanations for these results correspond with the observed performance differences. After training, endurance-trained lizards had higher haematocrit and larger fast glycolytic muscle fibres. Despite no detectable change in maximal performance of sprint-trained lizards, we detected that they had significantly larger slow oxidative muscle fibre areas compared with the other treatments. Treatment groups did not differ in the proportion of number of fibre types, nor in the mass of most limb muscles or the heart. Our results offer some caveats for investigators conducting training research on non-model organisms and they reveal that muscle plasticity in response to training may be widespread phylogenetically.

Thermal dependence of sprint performance in the lizard Psammodromus algirus along a 2200-meter elevational gradient: Cold-habitat lizards do not perform better at low temperatures.

Sprint speed has a capital relevance in most animals' fitness, mainly for fleeing from predators. Sprint performance is maximal within a certain range of body temperatures in ectotherms, whose thermal upkeep relies on exogenous thermal sources. Ectotherms can respond to diverse thermal environments either by shifting their thermal preferences or maintaining them through different adaptive mechanisms. Here, we tested whether maximum sprint speed of a lizard that shows conservative thermal ecology along a 2200-meter elevational gradient differs with body temperature in lizards from different elevations. Lizards ran faster at optimum than at suboptimum body temperature. Notably, high-elevation lizards were not faster than mid- and low-elevation lizards at suboptimum body temperature, despite their low-quality thermal environment. This result suggests that both preferred body temperature and thermal dependence of speed performance are co-adapted along the elevational gradient. High-elevation lizards display a number of thermoregulatory strategies that allow them to achieve high optimum body temperatures in a low thermal-quality habitat and thus maximize speed performance. As for reproductive condition, we did not find any effect of it on sprint speed, or any significant interaction with elevation or body temperature. However, strikingly, gravid females were significantly slower than males and non-gravid females at suboptimum temperature, but performed similarly well at optimal temperature.

A stringent test of the thermal coadaptation hypothesis in flour beetles.

Whole-organism performance depends on body temperature and ectotherms have variable body temperatures. The thermal coadaptation hypothesis posits that thermal reaction norms have coevolved with thermal preference such that organisms attain optimal performance under a narrow range of body temperatures commonly experienced in the wild. Since thermal reaction norms are often similar, researchers interested in the effects of temperature on fitness often use one easily measured thermal reaction norm, such as locomotor performance, and assume it is a good proxy for fitness when testing the thermal coadaptation hypothesis. The extent to which this assumption holds, however, is often untested. In this study, we provide a stringent test of the thermal coadaptation hypothesis in red and in confused flour beetles by comparing the thermal reaction norm for reproductive output to the preferred body temperature range. We also test the assumption that locomotor performance can serve as a proxy for the thermal reaction norm for reproductive output, a more ultimate index of fitness. In both species, we measured the number of eggs laid, righting time, and sprint speed at eight temperatures, as well as the thermal preference in a thermal gradient. The number of eggs laid increased with female sprint speed and with male righting time, and all three performances had similar thermal reaction norms, with 80% of the maximum achieved between 23 and 37°C. Red flour beetles had preferred body temperatures that matched the optimal temperature for performance; confused flour beetles had lower preferred body temperature than the optimal temperature for performance. We found support for the assumption that locomotor performance can serve as a proxy for reproductive output in flour beetles, but we only found evidence for thermal coadaptation in one of the two species.

Match-Play Running Performance in Professional Male Soccer Players: The Role of Anaerobic Speed Reserve.

Purpose: This study aimed to compare match-play running performance between players with a high (HASR) and low (LASR) anaerobic speed reserve (ASR) profile in professional soccer players. Method: Thirty-six male players from the same club (age: 23.3 ± 5.4 years) took part in this study. Match data were collected from 43 home matches of the first and second division of the Brazilian National Championship over two consecutive seasons. Players had their maximal sprinting (MSS) and aerobic speeds (MAS) determined during field test-based assessments. ASR was defined as MSS minus MAS. Total distance (TD), sprinting distance, number of accelerations and decelerations, absolute peak (PMS(abs)) and mean match sprint speed (MMSS(abs)) and its relative values expressed as a percentage of MSS (PMS(rel) and MMSS(rel)), distance covered > 100% MAS(abs) and > 50% MSS(abs) were compared between the groups and halves. Results: HASR presented greater sprint demand (d > 0.80), PMS(abs) (d = 1.57), and MMSS(abs) (d = 0.99) than the LASR group. The opposite was observed for PMS(rel) and MMSS(rel). The TD and amount of high-intensity accelerations and decelerations were moderately (0.77MAS(abs) and > 50% MSS(abs) decreased between halves (d = 0.72 and 0.77), while the HASR did not (d < 0.10). Conclusion: Our findings indicated that players with larger ASR had greater sprint demand, with a lower relative running intensity, and covered longer distances above MAS. The amplitude of ASR also affected the player's running ability between halves.