Mechanical peak power output (PPO) is a determinant of performance in sprint cycling. The purpose of this study was to examine the relationship between PPO and putative physiological determinants of PPO in elite cyclists, and to compare sprint performance between elite sprint and endurance cyclists. Thirty-five elite cyclists (18 endurance; 17 sprint) performed duplicate sprint cycling laboratory tests to establish PPO and its mechanical components. Quadriceps femoris (Q VOL ) and hamstring muscle volume (HAM VOL ) were assessed with MRI, vastus lateralis pennation angle (Pθ VL ) and fascicle length (FL VL ) were determined with ultrasound imaging, and neuromuscular activation of three muscles was assessed using EMG at PPO during sprint cycling. For the whole cohort, there was a wide variability in PPO (range 775-2025 W) with very large, positive, bivariate relationships between PPO and Q VOL (r = .87), HAM VOL (r = .71), and Pθ VL (r = .81).Step-wise multiple regression analysis revealed that 87% of the variability in PPO between cyclists was explained by two variables Q VOL (76%) and Pθ VL (11%). The sprint cyclists had greater PPO (+61%; P < .001 vs endurance), larger Q VOL (P < .001), and BF VOL (P < .001) as well as more pennate vastus lateralis muscles (P < .001). These findings emphasize the importance of quadriceps muscle morphology for sprint cycling events. K E Y W O R D S maximum cadence, maximum power, maximum torque, muscle How to cite this article: Kordi M, Folland J, Goodall S, et al. Mechanical and morphological determinants of peak power output in elite cyclists. Scand J Med Sci Sports.

Introduction This study aimed to assess the efficacy of a 6‐week cycling‐specific, isometric resistance training program on peak power output (PPO) in elite cyclists. Methods Twenty‐four elite track sprint cyclists were allocated to EXP (n = 13, PPO, 1537 ± 307 W) and CON (n = 11, PPO, 1541 ± 389 W) groups. All participants completed a 6‐week training program; training content was identical except participants in the EXP group replaced their usual compound lower body resistance training exercise with a cycling‐specific, isometric resistance training stimulus. Cycling PPO, knee extensor and cycling‐specific isometric strength, and measures of muscle architecture were assessed pre‐ and post‐training. Results In EXP, absolute and relative PPO increased (46 ± 62 W and 0.8 ± 0.7 W/kg, P < .05), and the change in relative PPO was different to CON (−0.1 ± 1.0 W/kg, group × time interaction P = .02). The increase in PPO was concurrent with an increase in extrapolated maximal torque in EXP (7.1 ± 6.5 Nm, P = .007), but the effect was not different from the change in CON (2.4 ± 9.7 Nm, group × time P = .14). Cycling‐specific isometric strength also increased more in EXP (group × time P = .002). There were no other between‐group differences in response to training. Conclusion A 6‐week novel, cycling‐specific isometric resistance training period improved PPO in a group of elite sprint cyclists by 3%‐4%. These data support the use of a cycling‐specific isometric resistance training stimulus in the preparation programs of world‐class cyclists.

Growth-related and overuse injuries are commonly reported in young gymnasts. Two risk factors of these injuries are growth and maturation, and training load. However, little is known regarding current coaching knowledge and practice in relation to these risk factors. To help understand current knowledge and practice, 44 coaches of competitive, young gymnasts, from 3 gymnastics disciplines (men’s artistic, women’s artistic, trampoline) took part in focus groups. The focus groups explored the awareness, experience and practice of coaches in relation to growth and maturation, training load and injury in competitive, young gymnasts. Data were analysed manually using an inductive thematic approach to identify core themes. The findings showed that coaches were aware of the physical changes and injuries that occur during the adolescent growth spurt. Both psychological changes and skill loss/confusion were also identified as challenges during this time. The knowledge and practice of monitoring growth and maturation, and training load did however differ between disciplines. Sports science and medicine practitioners were recognised as key stakeholders in helping manage and reduce the risk of injuries during growth. There appears to be gap between coach knowledge of growth and maturation, and training load, and practices such as monitoring training load and growth. Educating coaches and further research in these areas will aid coaches in reducing the risk of injuries in young, competitive gymnasts.