Competitive Marathon Runners Exhibit Greater Running Economy than Recreational Runners

Abstract

INTRODUCTION: Running economy (RE) has been identified as a predictor of distance running performance. More experienced runners are generally more economical than novice or recreational runners, requiring less oxygen to cover the same distance. Given the metabolic cost of marathon running, it was hypothesized that competitive runners (COMP) would be more economical than recreational runners (REC), and that RE at sub-maximal paces would be associated with marathon performance (MP) in both groups. PURPOSE: To compare RE in COMP versus REC runners, and to determine whether it is associated with MP in each group. METHODS: Twenty-nine runners (ages 18-47, 15 male and 14 female) completed a time trial or road race (from 2-miles to 10-km), a 30-minute sub-maximal treadmill run progressing through 6 stages of 5-min from 75 to 100% of 10-km race velocity, and a 26.2 mile road marathon. If necessary, velocities for the 30-min run were set by converting race times to a 10-km equivalent. Oxygen use was assessed continuously during the 30-min run via metabolic cart. Projected marathon finish times were determined using published race time equivalency charts. Marathon performance was reported as percent difference from predicted finish time, with a positive value indicating a slower than expected marathon. Twelve runners (30 ± 8 years, 3 female) had projected marathon finish times of 3:10 or faster (2:58 ± 13 min) and were categorized as COMP, with the other nineteen runners (20 ± 1 years, 11 female) categorized as REC (4:18 ± 41 min). RESULTS: Average O2 use over the 30-min run was 194.7 ± 9.8 ml/kg/km for COMP and 211.6 ± 17.3 ml/kg/km for REC (p=0.005). Both groups ran slower than predicted for the marathon. The percent off expected MP for COMP was 1.7 ± 3.2% and for REC was 15.7 ± 5.8% (p≤0.001). For all runners, O2 use was associated with MP (p≤0.001). By group, there was a trend toward an association between RE and MP. The correlations for REC and COMP runners were 0.419 (p=0.094) and 0.386 (p=0.215). CONCLUSIONS: Competitive runners are more economical than recreational runners and run closer to the marathon finish times predicted by shorter races. Within each category, runners with better RE tend to run closer to their predicted times in the marathon. Running economy may be a more important predictor of performance in the marathon than in races of shorter distances.