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 ((V) over dot O-2peak HRpeak, (V) over dot O-2.HR-1, (V) over dot (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 (V) over dot O-2 (63.0 +/- 7.4 vs 61.9 +/- 7.2 mL.kg(-1) min(-1)), (V) over dot (E) (147 +/- 37 vs 144 +/- 30 L.min(-1)), HR (188 +/- 5 vs 189 +/- beats.min(-1)), and (V) over dot O-2.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.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.