The use of lower-body eccentric resistance training to enhance strength and power in elite youth athletes

Abstract

Resistance training (RT) is effective for developing strength and power in youth athletes. Previously, research has mainly examined the effects of traditional resistance training (TRT) in which the load during both the eccentric and concentric phases are equal. Such an approach limits the development of eccentric strength and power qualities as greater forces are produced during eccentric muscle actions versus concentric. Eccentric resistance training (ERT) methods that can overload the eccentric phase of an exercise should be prescribed for youth athletes. In Publication 1, a narrative review appraised the physiological responses, benefits and current literature of ERT for youth athletes to enhance performance and reduce injury risk. Publication 2 surveyed the perceptions and current practices of ERT for youth athletes by 64 strength and conditioning (S&C) coaches. Results showed that whilst 96% of S&C coaches agreed that the inclusion of ERT for youth athletes was important, most only begun prescribing ERT in late adolescence compared to TRT which was largely implemented from childhood. Publication 3 reported that eccentric hamstring strength (EHS) can be reliably assessed by the Nordic hamstring exercise (NHE) in 64 youth male football players for both pre peak height velocity [PHV] (TE = 0.22-9.30N, CV = 4.8-5.7%) and mid-post PHV players (TE = 0.30-22.5N, CV = 7.2-8.5%). Publication 4 found six-weeks of NHE training increased EHS in both pre PHV (n = 8, d = 0.83) and post PHV (n = 16, d = 0.53) youth male soccer players. Results imply that less biologically mature players are perhaps more sensitive to increases in EHS from the NHE and that the training prescription for the NHE in more biologically mature players requires greater specificity. Publication 5 found prescribing either a one-minute (short) or three-minute (long) inter-set rest period (ISRI) between sets of the NHE did not significantly (p > 0.05) affect force production in 10 young male soccer players. However, results showed significant reductions in peak force from repetition four onwards in both dominant and non-dominant limbs (d = 0.58-1.28), indicating that the set configuration for the NHE requires consideration for youth athletes. Publication 6 reported similar increases in lower-body strength and power measures following six-weeks of either TRT (n = 8, d = 0.27-0.88) or flywheel inertia training (n = 8, d = 0.22-0.55) in elite academy rugby union players. Taken together, the findings from these publications demonstrate the safety, importance and application of ERT to enhance the performance of elite youth athletes.

Date of Award	2022
Original language	English
Awarding Institution	University of Brighton
Supervisor	Gary Brickley (Supervisor)