Effects of Resistance Training on Running Economy and Cross-country Performance

PURPOSE: Heavy-resistance training and plyometric training offer distinct physiological and neuromuscular adaptations that could enhance running economy and consequently distance-running performance. To date no studies have examined the effect of combining the two modes of training on running economy or performance. METHODS: Fifty collegiate male and female cross-country runners performed a 5-km time-trial and a series of laboratory-based tests to determine aerobic, anthropometric, biomechanical and neuromuscular characteristics. Thereafter, each athlete participated in a season of 6-8 collegiate cross-country races over 13 weeks. After the first four weeks, athletes were randomly assigned to either heavy-resistance or plyometric plus heavy-resistance training. Five days after completing their final competition, runners repeated the same set of laboratory tests. We also estimated effects of the intervention on competition performance throughout the season using athletes of other teams as controls. RESULTS: Heavy-resistance training produced small-moderate improvements in peak speed, running economy and neuromuscular characteristics relative to plyometric resistance training, whereas changes in biomechanical measures favored plyometric resistance training. Males made less gains than females in most tests. Both treatments had possibly harmful effects on competition times in males (mean 0.5%; 90% confidence limits ± 1.2%), but there may have been benefit for some individuals. Both treatments were likely beneficial for all females (- 1.2%; ± 1.3%), but heavy-resistance was possibly better than plyometric resistance training. CONCLUSION: The changes in laboratory-based parameters related to distance-running performance were consistent with the changes in competition times for females but only partly for males. Our data indicate that females should include heavy-resistance training in their programs, but males should be cautious about using it in season until more research establishes whether certain males are positive or negative responders