Effect Of Step Rate On Foot Strike Pattern And Running Economy In Novice Runners

Abstract

Purpose—The objective was to examine if step rates ±5% or ±10% of a novice runner's preferred step rate (SR) is sufficient enough to shift a novice runner’s foot strike pattern (FSP) (rear-foot, mid-foot, forefoot) and whether these SR changes produce changes in the rate of submaximal oxygen consumption (VO2). Methods—Foot strike angle (FSA) was recorded using sagittal plane video images and VO2 was measured for novice runners while running on a treadmill at a constant speed during increased and decreased (±5% and ±10%) SR conditions. Foot strike angle was used to predict strike index (SI) (predicted strike index = [FSA – 27.4]/-0.39) and quantify FSP in each SR condition. Results—Predicted SI was significantly different between preferred SR and the -5% (p = .014), -10% (p = .001), and the +10% (p = .007) SR conditions. There was a shift to higher predicted SI measures in the increased SR conditions and lower predicted SI measures in the decreased SR conditions. Oxygen consumption was significantly increased in the -5% and -10% SR conditions (p =.000 and p = .003, respectively). Conclusion-Manipulations of SR produce shifts in FSP in novice runners and these changes cause small changes in submaximal VO2. EFFECTS OF STEP RATE ON FOOT STRIKE PATTERN 3