Effects of Interval Training and a Taper on Cycling Performance and Isokinetic Leg Strength

The purpose of this study was to determine whether changes in isokinetic leg strength parallel changes in cycling performance during a six-week high-intensity aerobic interval training program and a subsequent two-week taper. Eleven male collegiate cyclists participated in one competitive cycling graded exercise test, four consecutive days of aerobic intervals (30 min @ 82.2±0.74% HRmax, 1:1 work:relife), and four continuous rides (l-2hr @ 65-80% HRmax) weekly. Pedalling cadence during training was generally 70-80 rpm suggesting a knee joint velocity of approximately 210°·sec-1. Cycling performance and peak isokinetic torque (TQpk) for knee flexors (HAM) and knee extensors (QUAD) @ 30, 120, 210, and 300°·sec-1 were assessed before, every two weeks during, and each week for two weeks following six weeks of interval training. Performance increased significantly during training (15%) and increased further during the taper (8%). QUAD TQpk @30 and 120°·sec-1 increased significantly during training and the taper. In contrast, QUAD TQpk @ 210 and 300°·sec-1 and HAM TQpk for all velocities were not significantly elevated following training. Interestingly, QUAD TQpk @ 300 but not 210°sec-1 significantly increased during the taper. Data from this study demonstrates that high-intensity aerobic interval cycling can promote gains in QUAD strength which occur primarily at contraction velocities slower than those utilized during cycling training. Additionally, a two-week taper can produce significant improvements in cycling performance (8%) and QUAD strength (8-9%) at 30 and 120°·sec-1, however, the time-courses for these improvements do not parallel one another