The Immune Response to Walking With and Without an Exercise Assist Device

Abstract

1754 PURPOSE: To measure immune changes related to walking with or without an exercise assist device compared to sitting. METHODS: Fifteen healthy and nonobese female subjects (37.5 ± 3.1 years of age) accustomed to regular walking were recruited and tested for aerobic power (VO2max 34.4 ± 1.4 ml/kg/min). During three randomly assigned 30 minute test sessions (4:00–4:30 pm), subjects functioned as their own controls and either sat in the laboratory, walked at ∼60% VO2max, or walked at the same treadmill speed using the BODY BAT® Aerobic Exerciser. This exercise assist device resembles a pair of baseball bats seamlessly joined together, and is held with both hands and swung to shoulder height across the body in a natural side to side pendulum motion. Saliva and blood samples were collected pre- and post-exercise, and 1-h post-exercise, with the data statistically analyzed using a 3 × 3 repeated measures ANOVA. RESULTS: Walking with the exercise assist device increased oxygen consumption 11±2% and heart rate 8±2 beats/min. The pattern of increase in blood counts for neutrophils, lymphocytes, monocytes, and natural killer cells, plasma interleukin-6, and PHA-induced lymphocyte proliferation differed significantly when comparing walking with sitting, but no differences were found between walking with or without the exercise assist device. No significant time or interaction effects were measured for plasma cortisol, salivary IgA output, or plasma IL-1ra. CONCLUSIONS: Use of an exercise assist device increased oxygen consumption 11% during walking, but did not alter the pattern of change in immunity measured during walking alone in comparison to sitting.