The effects of growth, maturation and training on strength and power development in young artistic female gymnasts

Abstract

Female artistic gymnastics demands a combination of physical abilities including strength,power and speed to perform a diverse set of skills. Although gymnasts’ training typicallycommences early in the prepubertal years, very little is known about how these physicalqualities develop due to the interaction of maturation and training and how these measuresinfluence vaulting performance. Chapter 3 showed that within- and between-session measuresof absolute (PFabs) and relative peak force (PFrel) from an isometric mid-thigh pull (IMTP) testwere reliable for both pre-peak height velocity [PHV] (CV ≤ 9.4%, ICC ≥ 0.87) and post-PHV(CV ≤ 7.3%, ICC ≥ 0.92). However, systematic bias was evident between-sessions 1 and 2 inthe pre-PHV group. Therefore, the IMTP was deemed a reliable method of measuring peakforce in pre- and post-PHV female athletes, providing that pre-PHV athletes attend anadditional familiarisation session.Chapters 4-6 revealed that the majority of absolute isometric and dynamic force-time variablesfrom the IMTP and jumping protocols increase with maturation. The IMTP results showedPFabs and absolute force at various time epochs were significantly greater in the most maturecohort compared to the least mature group of gymnasts (p 0.60). Verticaljumping performance improved with biological maturity, as evidenced by the most maturegymnasts’ producing significantly more absolute force (p 0.78), impulse (p 0.75), power (p 0.91) and jump heights (p 0.70) thanthe least mature group. No significant differences were observed in PFrel across the jumpingtests, although measures of relative peak power (PPrel) did significantly increase with maturity.All sprint-speed measures, standing long jump (SLJ) distance and vaulting vertical take-offvelocity were significantly greater in the more mature gymnasts (p 0.65). Thus,4maturation appears to have a significant influence on absolute isometric and dynamic force timevariables, sprint speed and vaulting vertical take-off velocity.Chapters 4-6 also indicated that across all tests, peak speed during a 20 m sprint protocol hasthe strongest association with vaulting vertical take-off velocity (R2 = 59%) and also identifiedthe ratio of vertical to horizontal take-off velocity (Ratiovert-hori) as a secondary determinant (R2= 12 %). Multiple regression analyses also revealed that of the jumping protocols, groundcontact time (GCT) and centre of mass displacement (COMΔ) from the drop jump [DJ] (14%), combined with maturity status (41 %) had the highest predictive ability of vertical take-offvelocity (R2 = 55 %). However, the IMTP failed to explain a large amount of variance (R2 =15%). Data indicate that maturation influences vaulting vertical take-off velocity in youngfemale gymnasts. Furthermore, our results highlight the importance of targeting peak sprintspeed alongside take-off technique to develop gymnasts’ ability to transfer linear speed tovertical take-off velocity.Study 4 (chapter 7) showed young female gymnasts significantly improved various kineticdeterminants of strength and power, sprint speed and vaulting take-off velocity afterparticipating in 10-months of supplementary neuromuscular training (GYM+NMT); changesthat were not typically evident in the gymnastics-training only (GYM) or maturity-matchedcontrol (CON) groups. Analyses revealed that the observed significant adaptations in theGYM+NMT training group occurred at different stages of the 10-month training program andvaried in magnitude (p < 0.05; g = 0.44-1.15). Isometric PFabs, horizontal jump distance andPeak momentum during sprinting significantly improved at each testing session from baseline.After 7-months of NMT, significant improvements were shown in isometric PFrel, CMJ heightand RSI and jump height in the DJ. The NMT stimulus took longer to transfer to sprinting and5vaulting performance, with peak sprint speed, spring-like behaviour in the DJ, and vaultingvertical take-off velocity significantly improving after 10-months. Overall, the findings fromthis study indicate that supplementary NMT can stimulate improvements in strength, power,speed and vaulting performance above and beyond those achieved through gymnastics trainingalone.