Improvement of cycling efficiency after strength training

Abstract

The purpose of this study was to find out the effect of the improvement of maximal dinamic strength on the energetic cost of cycling. Sixteen physical education students participated in this study, 10 males (23.5 ± 1.4 years, 176.1 ± 5.3 cm y 73.2 ± 6.1 kg) and 6 females (24.3 ± 2.2 years, 163.3 ± 5.8 cm y 60.7 ± 6.4 kg). First, we measured the dynamic strength in the half squat exercise with a test of maximal repetitions (between 3 and 12 repetitions, with 3 different load levels). Afterwards, we determined the IMR by extrapolation of the semilogaritmic relationship load/in number of repetitions. Then, the subjects followed a 6 weeks training program to improve the maximal dinamic strength (3 sesions/week), with an initial load per week of 12.215 ± 6.852 kg and an ending week load of 19.416 ± 13.289 kg. As a result of the training program IMR was improved by 33.9 ± 19% (p < 0.001), while the energetic cost of cycling, measured at 5 different load levels, decrease by 8.0 ± 5.2% (p < 0.001). Additionally, the corrected medial thigh circumference increased by 1.8 ± 2.7% (p < 0.05). The strength gain correlated with the increment in the corrected medial thigh circumference (r = 0.65, p < 0.05). Therefore, the improvement of the maximal dynamic strength in the half squat exercise can account for a decrease of the energetic cost of cycling.