Background: Although walking is the most common exercise modality in daily life for most humans, running and cycling are the most applied exercise modalities during maximal oxygen uptake (VO<inf>2max</inf>) testing. The aim of this study was to assess the reliability and validity of walking as exercise modality during VO<inf>2max</inf> testing.
Methods: Sixteen participants (25±3 years, 172±9 cm, 69±15 kg, and VO<inf>2max</inf> 50±4 mL/kg/min) performed four incremental running- and walking VO<inf>2max</inf> tests (two tests in each condition) within 2-3 weeks. During the walking condition, the speed was set to 7 km/h, and the treadmill incline increased by 2.5% each min until exhaustion. Results from these tests were validated against a running protocol with 5.3% treadmill incline where the speed increased by 1 km/h each min until exhaustion.
Results: The walking protocol achieved similar reliability values for absolute and relative VO<inf>2max</inf> when compared to the running condition. No significant differences in VO<inf>2max</inf> were observed between test session 1 and 2 for any of the tests. Significantly higher absolute VO<inf>2max</inf> (3.39±0.77 vs. 3.50±0.84 L/min; trivial difference) were observed in the running versus walking condition, while no significant differences in relative VO<inf>2max</inf>, BLa or Borg were detected. CVs for absolute and relative VO<inf>2max</inf> between the analyzed exercise modalities were ~5%.
Conclusions: Although the present participants achieved 2-3% lower VO<inf>2max</inf> when the walking test protocol was applied, walking seems to be a promising exercise-modality alternative during VO<inf>2max</inf> testing in clinical settings.