Of the few studies examining negative consequences associated with workloads , increases in training load led to increases in injury rates , while longer training duration was associated with a greater incidence of illness .
Conclusion The combined capacity for adolescent males to grow , train and improve physical performance highlights and underscores an exciting responsiveness to training in the football environment .
However , the capacity to train has some established barriers for adolescents experiencing high workloads , which could also result in negative consequences .
Background The expectation that training enhances performance is well explored in professional sport .
However , the additional challenges of physical and cognitive maturation may require careful consideration when determining workloads to enhance performance in adolescents .
Objective The objective of this study was to determine the state of knowledge on the relationship between workloads , physical performance , injury and /or illness in adolescent male football players .
Improving Repeated Sprint Ability in Young Elite Soccer Players: Repeated Shuttle Sprints Vs. Explosive Strength Training
Buchheit , M , Mendez-Villanueva , A , Delhomel , G , Brughelli , M , and Ahmaidi , S. Improving repeated sprint ability in young elite soccer players :  repeated shuttle sprints vs. explosive strength training . J Strength Cond Res 24(10 ) : 2715 - 2722 , 2010-To compare the effects of explosive strength ( ExpS ) vs. repeated shuttle sprint ( RS ) training on repeated sprint ability ( RSA ) in young elite soccer players , 15 elite male adolescents ( 14.5 ± 0.5 years ) performed , in addition to their soccer training program , RS ( n = 7 ) or ExpS ( n = 8) training once a week for a total of 10 weeks . RS training consisted of 2 - 3 sets of 5 - 6 × 15- to 20-m repeated shuttle sprints interspersed with 14 seconds of passive or 23 seconds of active recovery ( ≈2 m·s−1 ) ; ExpS training consisted of 4 - 6 series of 4 - 6 exercises ( e.g. , maximal unilateral countermovement jumps ( CMJs ) , calf and squat plyometric jumps , and short sprints ) . Before and after training , performance was assessed by 10 and 30 m ( 10 and 30 m ) sprint times , best ( RSAbest ) and mean ( RSAmean ) times on a repeated shuttle sprint ability test , a CMJ , and a hopping ( Hop ) test . After training , except for 10 m ( p = 0.22 ) , all performances were significantly improved in both groups ( all p 's < 0.05 ) . Relative changes in 30 m ( −2.1 ± 2.0 % ) were similar for both groups ( p = 0.45 ) . RS training induced greater improvement in RSAbest ( −2.90 ± 2.1 vs. −0.08 ± 3.3 % , p = 0.04 ) and tended to enhance RSAmean more ( −2.61 ± 2.8 vs. −0.75 ± 2.5 % , p = 0.10 , effect size [ ES ] = 0.70 ) than ExpS. In contrast , ExpS tended to induce greater improvements in CMJ ( 14.8 ± 7.7 vs. 6.8 ± 3.7 % , p = 0.02 ) and Hop height ( 27.5 ± 19.2 vs. 13.5 ± 13.2 % , p = 0.08 , ES = 0.9 ) compared with RS . Improvements in the repeated shuttle sprint test were only observed after RS training , whereas CMJ height was only increased after ExpS. Because RS and ExpS were equally efficient at enhancing maximal sprinting speed , RS training-induced improvements in RSA were likely more related to progresses in the ability to change direction
Of the few studies examining negative consequences associated with workloads , increases in training load led to increases in injury rates , while longer training duration was associated with a greater incidence of illness .
Conclusion The combined capacity for adolescent males to grow , train and improve physical performance highlights and underscores an exciting responsiveness to training in the football environment .
However , the capacity to train has some established barriers for adolescents experiencing high workloads , which could also result in negative consequences .
Background The expectation that training enhances performance is well explored in professional sport .
However , the additional challenges of physical and cognitive maturation may require careful consideration when determining workloads to enhance performance in adolescents .
Objective The objective of this study was to determine the state of knowledge on the relationship between workloads , physical performance , injury and /or illness in adolescent male football players .