TRAINING INTENSITY, NOT VOLUME OR FREQUENCY, IS RELATED TO PERFORMANCE IMPROVEMENT
Mujika, I., Busson, T., Geyssant, A., & Chatard, J. C. (1996). Training content and its effects on performance in 100 and 200 m swimmers. In J. P. Troup, A. P. Hollander, D. Strasse, S. W. Trappe, J. M. Cappaert, & T. A. Trappe (Eds.), Biomechanics and Medicine in Swimming VII (pp. 201-207). London: E & FN Spon.
Relationships between the average intensity of a training session, training volume, training frequency, and performance variations were studied in mature elite French swimmers (N = 18). Differences were also noted between swimmers who did and did not improve personal records across a season.
For all swimmers seasonal improvements were significantly correlated with the season's training intensity but not related to training volume or training frequency. Swimmers who declined most during the initial off-season improved less in the subsequent training season.
Implications. Training intensity is the key factor in the production of a training effect.
Maintain as much of the training effects gained in one season between seasons. The greater the off-season decline, the less likely an elite swimmer is to improve personal best times the next season.