The Effect of Two Different Methods of Carrying Weight on Oxygen Consumption and Lactates

Abstract

Past research has explored the effect of carrying extra weight on increased metabolic demand. However, few studies have focused on the manner in which the extra weight is carried - whether by hand or worn in a vest on the body. This is relevant in professions that require carrying equipment, such as firefighters and military personnel. PURPOSE: The purpose was to assess the difference in metabolic demand between carrying hand-held weights or an equal load on a weighted vest. METHODS: Ten college-age (20.8 ± 0.4 yr.) male varsity football players volunteered and were tested without extra weights for VO2max and blood lactate on a motorized treadmill. On separate days subjects returned to the lab and were randomly tested on the treadmill using an 8 minute walking protocol under one of two experimental conditions: 1) carrying two hand-held dumbbells equaling 40 lb.; 2) wearing a weighted vest weighing 40 lb. Three days following the first trial, subjects returned to complete the alternate experimental condition. Oxygen consumption data from the two experimental trials were expressed as a percent of the VO2max and mean differences were analyzed used paired T-tests. RESULTS: The results of the study showed a statistically significant difference in oxygen consumption between the two experimental trials, with hand held weights eliciting a higher percent of VO2max than the weighted vest (33.45 ± 5.08% vs. 28.85 ± 3.82%; P<0.01, respectively). Blood lactate levels were not significantly different between experimental conditions. CONCLUSIONS: These results suggest that carrying weight on a vest is more metabolically efficient than carrying an equal weight in the hands, and required a lower percentage of the VO2max.: