The Effect of Workload on Exercise Volume during Exhaustive Anaerobic Treadmill Running

Abstract

Anaerobic capacity has implications in health and sport performance. Sprint interval training improves anaerobic capacity, aerobic factors as well as performance. Optimal durations for taxing anaerobic capacity have been shown to be 60 seconds, and have been elicited using Anaerobic Speed Test (AST). In order to maintain this optimal duration for multiple sets, a decreasing workloads method must be used as fatigue increases following each set. These workloading methods must be compared to determine which protocol allows for the maximum exercise volume to be achieved. PURPOSE: The purpose of this study was to compare the effects of three different workload protocols on exercise volume completed during multiple sets of exhaustive anaerobic running on a treadmill. METHODS: Twelve male subjects (mean ± SD; age = 22.7 ± 4 yr, height:172.9 ± 6.9 cm, weight:75.9 ± 10.3 kg, VO2 max: 57.3 ± 6 ml/kg/min) completed three sessions of high intensity running on a graded treadmill with three different protocols using parameters adopted from the AST (20% grade, 8 mph to exhaustion). Four sets were completed during each protocol. Protocols included: 1) constant sets (CS): no descending workload in all four sets, 2) descending speed (DS): the speed is decreased by 10% for each subsequent set, 3) descending grade (DG): the grade is decreased by 10% for each subsequent set. RESULTS: Total exercise volume achieved during the four sets of the DS protocol was significantly higher than both the CS (p<0.01) and DG (p<0.01) protocols. Time to exhaustion achieved during the 2nd, 3rd and 4th sets of the DS protocol were significantly higher than the 2nd, 3rd and 4th sets of the CS protocol, all under p<0.01. Cadence during the 3rd set of the DS protocol was significantly lower than the 3rd set of the CS protocol (p<0.01). Additionally, cadence during the 4th set of the DS protocol was significantly higher than the 4th sets of the CS and DG protocols (p<0.01). CONCLUSIONS: The longer times per set and greater volume achieved during the DS protocol, in comparison to the DG and CS protocols, suggests the potential for a greater training effect. Differences in cadence values among the protocols could help explain differences in performance implicating muscle fiber type recruitment and fatigue.