European Journal of Applied Physiology

, Volume 94, Issue 1, pp 134–144

An energy balance of front crawl


    • Dipartimento di Scienze e Tecnologie BiomedicheUniversità degli Studi di Udine
  • D. R. Pendergast
    • Department of PhysiologyUniversity at Buffalo
  • J. Mollendorf
    • Department of Mechanical EngineeringUniversity at Buffalo
  • A. Termin
    • Department of AthleticsUniversity at Buffalo
  • A. E. Minetti
    • Institute of Biophysical and Clinical Research into Human MovementManchester Metropolitan University
Original Article

DOI: 10.1007/s00421-004-1281-4

Cite this article as:
Zamparo, P., Pendergast, D.R., Mollendorf, J. et al. Eur J Appl Physiol (2005) 94: 134. doi:10.1007/s00421-004-1281-4


With the aim of computing a complete energy balance of front crawl, the energy cost per unit distance (C= Ėv−1, where Ė is the metabolic power and v is the speed) and the overall efficiency (ηo=Wtot/C, where Wtot is the mechanical work per unit distance) were calculated for subjects swimming with and without fins. In aquatic locomotion Wtot is given by the sum of: (1) Wint, the internal work, which was calculated from video analysis, (2) Wd, the work to overcome hydrodynamic resistance, which was calculated from measures of active drag, and (3) Wk, calculated from measures of Froude efficiency (ηF). In turn, ηF=Wd/(Wd+Wk) and was calculated by modelling the arm movement as that of a paddle wheel. When swimming at speeds from 1.0 to 1.4 m s−1, ηF is about 0.5, power to overcome water resistance (active body drag × v) and power to give water kinetic energy increase from 50 to 100 W, and internal mechanical power from 10 to 30 W. In the same range of speeds Ė increases from 600 to 1,200 W and C from 600 to 800 J m−1. The use of fins decreases total mechanical power and C by the same amount (10–15%) so that ηo (overall efficiency) is the same when swimming with or without fins [0.20 (0.03)]. The values of ηo are higher than previously reported for the front crawl, essentially because of the larger values of Wtot calculated in this study. This is so because the contribution of Wint to Wtot was taken into account, and because ηF was computed by also taking into account the contribution of the legs to forward propulsion.


SwimmingBiomechanicsEnergeticsPropelling efficiencyFins

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© Springer-Verlag 2005