Explosive-strength training improves 5-km running time by improving running economy and muscle power

To investigate the effects of simultaneous explosive-strength and endurance training on physical performance characteristics, 10 experimental (E) and 8 control (C) endurance athletes trained for 9 wk. The total training volum e was kept the same in both groups, but 32% of training in E and 3% in C wa s replaced by explosive-type strength training. A 5-km time trial (5K), run ning economy (RE), maximal 20-m speed (V-20m), and 5-jump (5J) tests were m easured on a track. Maximal anaerobic (MART) and aerobic treadmill running tests were used to determine maximal velocity in the MART (V-MART) and maxi mal oxygen uptake ((V)over dot(O2max)). The 5K time, RE, and V-MART improve d (P < 0.05) in E, but no changes were observed in C. V-20m and 5J increase d in E (P < 0.01) and decreased in C (P < 0.05). (V)over dot(O2max) increas ed in C (P < 0.05), but no changes were observed in E. In the pooled data, the changes in the 5K velocity during 9 wk of training correlated (P < 0.05 ) with the changes in RE [O-2 uptake (r = -0.54)] and VMART (r = 0.55). In conclusion, the present simultaneous explosive-strength and endurance train ing improved the 5K time in well-trained endurance athletes without changes in their (V)over dot(O2max). This improvement was due to improved neuromus cular characteristics that were transferred into improved V-MART and runnin g economy.