Contrasting Product Claims With Actual Physiological Measurements Of Popular “Exercise” Equipment

Abstract

People around the world are increasingly aware of their need to exercise regularly. Many of them are turning to simple, attractive solutions they see on television, but not all countries have equally strict regulations for assessment of product claims, and the criteria for scientific support appear to be lax for exercise equipment. It would be unfortunate for people to purchase useless equipment and give up exercise because of a lack of positive results. PURPOSE: to measure the acute physiological response to using a popular piece of equipment, commercially available in Costa Rica. METHODS: 1) VO2 was tested at rest and using the equipment with a Jeager MasterScreen CPX metabolic cart (CareFusion Corporation, San Diego, CA). Energy expenditure was calculated simultaneously from heart rate (Polar FT7, Kempele, Finland) (HRM), accelerometry (Actigraph wgT 3x-BT, Pensacola, FL) (ACC), and a pedometer (3DActive PDA-100, London, UK) (PED). 27 young, apparently healthy students (15F, 12M) rested in a supine position for 10 min while measuring oxygen consumption. They proceeded to use the exercise machine according to manufacturer’s instructions, in the highest setting, for 10 min (EXER). RESULTS: All data are Mean±SD. Subjects were 19.1±1.0 y.o., 1.647±0.073 m tall, and weighed 63.09±10.13 kg; resting VO2 = 3.2±0.7 mL*kg-1*min-1. During EXER, calculated energy expenditure was highest with PED (63.3±7.6 kcal, gross), registering 2099.1±250.5 “steps”; HRM recorded 24.7±7.9 kcal (gross), while ACC recorded 0.8±1.2 kcal (net) during those 10 min. Exercise intensity was measured from VO2 at 1.54±0.23 METs, corresponding to 5.6±2.2 kcal of net (16.8±2.8 kcal gross) 10-min energy expenditure. CONCLUSION: Not even the least accurate, most generous measurement using PED was close to the infomercial claim of 277 kcal in 10 min for a lean, small female runner. The actual net energy expenditure while using this equipment, as carefully measured in this study with indirect calorimetry, will result in an insignificant amount of body fat loss, even if used for a full hour every day. Users are advised to save their money and buy two or three good pairs of walking shoes instead. Funded by the University of Costa Rica, project VI-838-B6-766.