Prediction of oxygen uptake during level treadmill walking in people with multiple sclerosis

Objective: To determine whether the oxygen uptake (VO₂) during walking at different speeds in people with multiple sclerosis is underestimated by available prediction equations and whether such underestimation relates to the validity of their assumptions. Design: Cross-sectional comparison. Subjects: Eighteen adults with multiple sclerosis and 18 adults without multiple sclerosis. Methods: VO₂ was measured at rest and during treadmill walking at 2.0,3.0 and 4.0 mph with open-circuit spirometry. The actual VO ₂ was compared with that estimated by both the American College of Sports Medicine and the van der Walt and Wyndham equations. Results: The differences between the actual VO₂ and that estimated by both equations were significantly higher than zero across speeds for both groups (p<0.001). The underestimation increased with increasing speed (/><0.001) for both groups and was greater for participants with multiple sclerosis than those without multiple sclerosis (p<0.011). The inaccurate prediction by the American College of Sports Medicine formula was associated with an underestimation of the net VO₂ per meter (p<0.001), and this was higher for participants with multiple sclerosis (p<0.007). Conclusion: Rehabilitation and exercise professionals should recognize that the American College of Sports Medicine and the van der Walt and Wyndham equations underestimate VO₂ during treadmill walking in individuals with and without multiple sclerosis.