The Effects of Chest Constriction at Rest on Aerobic Capacity

Abstract

PURPOSE: This was a pilot study investigating whether an externally applied thoracic constriction band at rest over a four-week period, can improve aerobic capacity without having to perform aerobic exercise. METHODS: 15 sedentary college age individuals (between 18–35 yrs) were studied over a period of 4 weeks during which they participated in their normal everyday activities. Participants completed an activity questionnaire, a Physical Activity Readiness Questionnaire (Par-Q) and an aerobic capacity (VO2max) test. VO2max was measured Pre and Post 4 weeks using the 1.5-mile run/walk field test. Participants were instructed to cover the specified distance in the fastest time possible. A VO prediction equation (VO2max (ml kg−1. min−1) = 3.5 + 483/ (time in minutes)) was used. Following pre testing, participants were randomly placed into one of two groups: (1) Chest Wall Restriction Group (CWR) (n = 10), or (2) Control (Non-Chest Wall Restriction Group (N-CWR)) (n=5). Each participant in the Chest Wall Restriction Group (CWR) had their chest wall restricted with the use of an elastic strap for 1.5 hours 5 days/week. Strap widths ranged from 10 to 15 cm adjusted to fit just beneath the axillae and around the chest to envelop the rib cage. It is worth noting that this apparatus does not prevent the chest wall from expanding like earlier studies, but offers elastic eccentric resistance for the inspiratory muscles to work against. RESULTS: A significant 11 ± .07% improvement in aerobic capacity was observed in the experimental group (P <0.05). Estimated VO2max values for CWR increased from 27.92 ±5.98 to 31.46 ± 6.42, while the N-CWR group showed no significant change (30.22 ± 5.67 to 30.51 ±5.61). Units for VO2max are shown in ml.min−1. kg−1 ± SD. CONCLUSION: This pilot study shows the potential benefit of wearing an externally applied thoracic constriction band at rest. Sedentary individuals with low exercise tolerance may be able to increase their aerobic capacity without performing aerobic exercise.