Please cite this article in press as: Maciejczyk M, et al. Longitudinal changes of cycling peak power in overweight and normal weight boys. Sci sports (2014), http://dx.doi.org/10.1016/j.scispo.2014.09.005 ARTICLE IN PRESS +Model SCISPO-2904; No. of Pages 7 Science & Sports (2014) xxx, xxx—xxx Disponible en ligne sur ScienceDirect www.sciencedirect.com ORIGINAL ARTICLE Longitudinal changes of cycling peak power in overweight and normal weight boys Évaluation du pic de puissance chez des enfants en surpoids M. Maciejczyk a,* , J. Szymura b , J. Gradek c , J. Cempla a , M. Wiecek a a Institute of Biomedical Sciences, Department of Physiology and Biochemistry, University of Physical Education, Al. Jana Pawla II 78, 31-571 Kraków, Poland b Department of Clinical Rehabilitation, University of Physical Education, Kraków, Poland c Institute of Sport, University of Physical Education, Kraków, Poland Received 7 May 2014; accepted 29 September 2014 KEYWORDS Anaerobic; Muscle power; Force—velocity relationship; Body composition; Allometric scaling; Obesity; Body fat; Puberty; Maturation; Boys Summary Objective. — The purpose of this study was to assign cycling peak power (CPP) in overweight boys, and to determine the longitudinal changes in CPP over the period of 10 to 14 years of age. Methods. — Eleven overweight and fourteen normal weight boys took part in three exercise tests, which were conducted every two years. The force—velocity test was used to measure CPP. The workload in the force—velocity test was assigned in relation to fat-free mass (FFM). Optimal braking force was defined as the workload used during the sprint in which the highest cycling power was reached. Results. — The CPP (absolute, relative to free-fat mass, and to body mass raised to the 0.67 exponent) was comparable in overweight and normal weight boys. The relative to body mass CPP was significantly lower in the overweight boys. During growth, systematical increase in the difference in CPP between overweight and normal weight boys was noted. The cycling peak power was noted in both groups at a similar relative to the FFM optimal braking force. Conclusion. — Longitudinal changes of CPP indicated the constant impairment of anaerobic per- formance in overweight boys. During growth, the gain of relative to body mass and to FFM cycling peak power is lower in overweight than in normal weight boys. Optimal braking force in pre-pubertal boys remained at a similar level but significantly increased at puberty. This finding should be taken into account for planning measurements of CPP in pre-pubertal and circumpubertal children. © 2014 Elsevier Masson SAS. All rights reserved. ∗ Corresponding author. E-mail address: marcin.maciejczyk@awf.krakow.pl (M. Maciejczyk). http://dx.doi.org/10.1016/j.scispo.2014.09.005 0765-1597/© 2014 Elsevier Masson SAS. All rights reserved.