Moderate-vigorous Intensity Run Vs. Walk On Hemodynamics, Metabolism And Perception Of Effort

Abstract

The ability to use an alternative (i.e., walking) to running would provide great benefit to those who are uncomfortable running or can’t run, in order to meet minimum activity recommendations. PURPOSE: We compared two exercise modalities (Run, Walk) matched for VO2, on HR, RPE, and a visual analog scale (VAS). METHODS: Active, college-aged males (n=7; weight = 72.5 + 3.9 kg; Bf% = 17.9 + 1.2; VO2max = 51.5 + 1.36 mL/kg/min) participated in a crossover-designed study, and studied on each of 2 occasions: Walk (W) and Run (R). Subjects completed a body composition and VO2max test. (R) = 60-min on a treadmill at 0%grade and speed equal to 65% VO2max (694.4 + 26.1 kcal). (W) = 60-min at 3.3mph and a steep incline equal to 65% VO2max (677.9 + 20.9 kcal). Pulmonary gas exchange (VO2, RER, respiratory rate (RR)) was assessed within the first 10 min of exercise, with HR and RPE recorded every 15 min. A VAS was used to assess overall perceived effort (0-100mm). RM ANOVAs were used for statistical analysis. Values were calculated as mean + SE. RESULTS: There was no significant difference in VO2 (Run, 33.2 ± 1.1; Walk, 32.7 ± 1.1 mL/kg/min; Con, p=0.59), RPE (Run, 11.1 + 0.8; Walk, 11.7 + 0.8, p=0.28), VAS (Run, 51.2 ± 5; Walk, 48 ± 5mm, p=0.54), or %VO2max (Run, 64.6 + 1.2; Walk, 63.5 + 1.2%, p=0.56) between the groups. There was a significant difference in HR (Run, 167.0 + 4.9; Walk, 157.3 + 4.9 BPM), RR (Run, 35.1 + 2.3; Walk, 30.5 + 2.3 BPM), and RER (Run, 0.86 + 0.02; Walk, 0.9 + 0.02) between the groups. There was no significant difference in the amount of sleep (R, 6.6; W, 6.8hr) between the two groups (p=0.68). 5 out of 7 subjects complained about their legs “burning” or “hurting” during the W trial. CONCLUSION: Walking and Running, even when matched for intensity, via VO2, led to the R having a significantly higher HR and breathing rate for 60-min in active males, but a significantly lower RER. Despite the subjects complaining of their legs being sore (W), RPE did not reflect a difference in perception, nor did the VAS post-exercise. These results indicate that a walk can be recommended for a moderate-vigorous intensity, and elicit a similar metabolic and hemodynamic response, without causing a significant increase in perceived effort. This promotes the use of “steep” walking as energetically beneficial for those not able or desiring to run at higher intensities.