Commitment to a structured and progressive strength and conditioning program can have a tremendous impact on the performance potential of an athlete. However, unless coaches keep records of changes in both performance markers and markers of strength and power, it is difficult to determine the magnitude of these improvements and if they’re related. For example, maximal lower body strength is often correlated with vertical jumping ability and sprinting speed in cross-sectional studies. Comparably less research has been done that demonstrates a relationship between longitudinal improvements in lower body strength or power and improvements in athletic performance tasks. Collegiate athletes are exposed to mandatory strength and conditioning training throughout their college playing career and therefore evaluating yearly changes in performance among this population can provide insight regarding the effects of chronic strength and power training on performance.
A new study published ahead of print in the Journal of Strength and Conditioning Research evaluated yearly changes in strength, power and performance among a NCAA Division-1 women’s volleyball team. A team of 29 volleyball players were grouped according to how many years of strength and conditioning training they had been exposed to with the team. The groups included individuals with 0-1 years of training, 1-2 years of training and 2-3 years of training. The variables that were monitored across time included static and countermovement jump heights (unloaded and with 11 and 20 kg of resistance) and peak force production from an isometric mid-thigh pull on a force plate. The researchers determined the magnitude of changes in each variable for each group to determine: 1) the improvement observed after ~1, ~2 and ~years of training relative to initial baseline testing when athletes first joined the team.
The results showed that static and countermovement jump variables demonstrated average improvements of 5.6 – 12.3% following 1 year of training, 6.6 – 12.7% following 2 years of training and 16.6 – 30.6% after 3 years of training. Peak force production from the isometric mid-thigh pull demonstrated an average improvement of 20.5% after 1 year of training, 22.2% after two years of training and 31.5% after three years of training. The authors conclude that a combination of traditional resistance training and Olympic weightlifting (in combination with volleyball training) can stimulate long term improvements in maximal strength and jumping ability in collegiate volleyball players. This was observed despite no additional plyometric training outside of volleyball practice.
Kavanaugh, A.A., et al. Long-term changes in jump performance and maximum strength in a cohort of CAA Division I women’s volleyball athletes. Journal of Strength and Conditioning Research, In press.