Comparison Of Oxygen Uptake Between Forefoot And Rearfoot Striking Runners: A Pilot Study

Emerging research has focused on foot strike dynamics as it relates to athletic performance and running economy. However, limited research has been conducted measuring running economy and foot strike in high-level distance (1,500-10,000 meters) athletes at race-specific speeds. PURPOSE: The purpose of this pilot study was to examine the oxygen consumption of highly trained distance runners, some of which employ a rearfoot strike (RFS) pattern and some who non-rearfoot strike (NRFS) at speeds similar to what they encounter in race settings. METHODS: Six male division II cross country athletes, mean age 21 ± 2.3 years participated. Athletes were classified as RFS (n = 3) and NRFS (n = 3) based on the index of their initial ground contact (RFS = proximal 33% of the foot; NRFS = distal 66% of the foot). The participants completed a 10-minute ramped running protocol at an approximation of their lactate threshold pace, peaking at the speed they could maintain in a 5000 m race. Due to low numbers, a qualitative, descriptive comparison of oxygen consumption was made between the RFS and NRFS pattern runners. RESULTS: General trends were found regarding oxygen consumption between runners grouped by foot strike (Table 1). At the initial speeds RFS runners had lower oxygen consumption from 0-4 minutes, and at minute 4 the two groups had near equal values. The rates of oxygen consumption flipped by minute 5 where the RFS group began to have greater mean oxygen uptake compared to the NRFS group. This trend continued until the final minute of the test where the difference in oxygen consumption reached a maximum between groups. CONCLUSION: Initial results indicated that RFS group had lower rates of oxygen consumption at slower running speeds, while NRFS had lower rates of oxygen consumption at higher speeds. Additional research is needed to confirm these trends. TABLE 1. - Mean oxygen uptake values (mL O2·kg-1·min-1) for NRFS and RFS runners Time (min) NRFS Mean VO2 RFS Mean VO2 1 36.3 ± 7.6 33.8 ± 4.4 2 44.2 ± 1.9 42.8 ± 4.6 3 47.3 ± 0.8 47.0 ± 4.5 4 50.0 ± 2.0 50.3 ± 3.1 5 53.1 ± 1.2 54.4 ± 4.4 6 55.2 ± 0.8 57.8 ± 5.3 7 57.9 ± 1.6 59.3 ± 4.2 8 59.6 ± 2.0 61.9 ± 4.7 9 59.2 ± 1.7 62.7 ± 2.6 10 61.0 ± 2.5 65.6 ± 2.9