Introduction: Previous research examining the metabolic cost and velocity contributions of the upper and lower limbs in elite swimmers has not considered the impact of stroke and kick rate. This study aimed to determine the metabolic cost, VO2 and velocity production of arms only and legs only swimming relative to whole body swimming at different intensities while controlling stroke and kick rate. Method: Twenty elite swimmers completed six 200m swimming trials; two with the whole stroke (swim), two with the arm stroke only (pull) and two with the leg kick only (kick). The swim trials were completed at two submaximal intensities (60% and 75% of the fastest 200m freestyle time at the 2012 Olympic Games). In the pull trials, swimmers matched the stroke rates recorded during the swim trials, while the kick rates from the swim trials were matched in the kick trials. Oxygen uptake (VO2) was continuously measured throughout, with metabolic cost and velocity calculated for each 200m effort. One-way repeated measures ANOVAs were used to identify differences in velocity, VO2 and metabolic cost among swim, pull and kick trials. Results: Irrespective of intensity, mean velocity and VO2 of the pull and kick trials were lower than the swim trials (p<0.01). For both intensities, the metabolic cost of pull was lower than swim (p<0.02), while the metabolic cost of kick was equal to swim (p>0.05). Velocity, VO2 and metabolic cost of the swim trial were all significantly lower than the sum of pull and kick at both intensities (p<0.01). When the sum of pull and kick was normalised to the magnitude of swim, the arms contributed 63.3±6.4% and 59.7±4.4% of velocity, utilised 55.5±6.9% and 51.9±4.6% of the VO2 and were responsible for 43.9±9.5% and 46.0±8.1% of the metabolic cost at the low and high intensities, respectively. Conclusion: To determine the relative contributions of the upper and lower limbs to performance, simply summing the velocity and/or energy consumption of arms only and legs only swimming, even when stroke and kick rates are matched among testing conditions, will be misleading. Normalising the sum of pull and kick data to swim data indicates that the legs may contribute more to velocity than previously reported. While VO2 during whole body swimming appears to be divided evenly between the upper and lower limbs based on the normalised data, the upper limbs use this energy more effectively. Implementation of this testing protocol before and after a pull or kick training block will enable sports scientists to identify how the velocity contributions and/or metabolic cost of the upper and lower limb actions have responded to the training stimulus.
© Copyright 2016 21st Annual Congress of the European College of Sport Science (ECSS), Vienna, 6. -9. July 2016. Published by University of Vienna. All rights reserved.