Comparison of incremental treadmill exercise and free range running.

PURPOSE: The aim of this study was to compare physiological responses during incremental treadmill exercise and free range running.

METHODS: Fifteen competitive cross-country runners performed an incremental treadmill test and an unpaced 1-mile run on an indoor 200-m track. Physiological variables (VO(2peak), HR(peak), VO(2) x HR(-1)(peak), V(Epeak)) were measured using a portable metabolic analyzer. Blood lactate was measured post exercise. Outcome variables were analyzed with repeated measures ANOVA.

RESULTS: Although directionally similar to previous studies with cycle ergometry, the observed peak values (track vs treadmill) for VO(2) (63.0 +/- 7.4 vs 61.9 +/- 7.2 mL x kg(-1) x min(-1)), V(E) (147 +/- 37 vs 144 +/- 30 L x min(-1)), HR (188 +/- 5 vs 189 +/- 7 beats.min-1), and VO(2) x HR(-1) (22.1 +/- 4.4 vs 21.5 +/- 4.5) were not significantly different. The observed peak values for blood lactate (14.4 +/- 3.3 vs 11.7 +/- 3.0 mmol x L(-1)) were significantly (P < 0.05) different.

CONCLUSIONS: The results are not in full agreement with previous findings from cycling studies with the exception of post exercise blood lactate. Whether this represents a fundamental lack of effect of free range exercise or is related to mode specificity remains to be determined.