Influence of Step Rate Manipulation on Foot Strike Pattern and Running Economy.

Context: With the rise in distance running, there is an increasing interest in reducing running-related injuries and improving performance. Foot strike patterns (FSP) and step rate (SR) are key factors in managing the external forces generated during foot contact in running. Adjusting SR may help alter FSP and improve running economy (RE), yet its effects on recreational runners are not fully understood. Thus, this study aimed to examine if SR manipulations are sufficient to shift FSP and whether the manipulations change the RE.

Design: Cross-sectional study.

Methods: Eighteen healthy recreational runners' (age: 30.2 [7.6] y) foot strike angle was calculated using 2D video motion analysis, and submaximal VO2 was measured while running on a treadmill during preferred and adjusted (±5% and ±10%) SR conditions. Foot strike angle was used to predict strike index and quantify FSP, and submaximal VO2 was analyzed to determine RE.

Results: Predicted strike index was significantly different between preferred SR and the -10% (P = .002), -5% (P = .002), and +10% (P < .001) SR conditions. Submaximal VO2 was significantly increased in the -10% (P < .001) and -5% (P = .002) SR conditions.

Conclusion: SR manipulations were sufficient to alter foot strike angle and predicted strike index in recreational runners, leading to moderate to significant changes in RE. These findings suggest that SR manipulation can be a useful tool for influencing FSPs and optimizing RE to enhance performance and reduce injury risk.