Heavy reliance on carbohydrate across a wide range of exercise intensities during voluntary arm ergometry in persons with paraplegia. (September 2013)

• Record Type: Journal Article
• Authors: Jacobs, Kevin A.; Burns, Patricia; Kressler, Jochen; Nash, Mark S.
• Is Part Of: Journal of spinal cord medicine. Volume 36:Number 5(2013:Sep.)
• Page Start: 427
• Page End: 435
• Publication Date: 2013-09
• Subjects: Spinal cord injuries -- Paraplegia -- Ergometry -- Energy metabolism -- Physical exertion -- Carbohydrates -- Fats; Spinal cord -- Wounds and injuries -- Periodicals; Spinal cord -- Diseases -- Periodicals; 616.8305
• DOI: 10.1179/2045772313Y.0000000123
• Languages: English
• ISSNs: 1079-0268

Abstract

Abstract : Context/objective: To describe and compare substrate oxidation and partitioning during voluntary arm ergometry in individuals with paraplegia and non-disabled individuals over a wide range of exercise intensities. Design: Cross-sectional study. Setting: Clinical research facility. Participants: Ten apparently healthy, sedentary men with paraplegia and seven healthy, non-disabled subjects. Interventions: Rest and continuous progressive voluntary arm ergometry between 30 and 80% of peak aerobic capacity (VO2peak ). Outcome measures: Total energy expenditure and whole body rates of fat and carbohydrate oxidation. Results: A maximal whole body fat oxidation (WBFO) rate of 0.13 ± 0.07 g/minute was reached at 41 ± 9% VO2peak for subjects with paraplegia, although carbohydrate became the predominant fuel source during exercise exceeding an intensity of 30–40% VO2peak . Both the maximal WBFO rate (0.06 ± 0.04 g/minute) and the intensity at which it occurred (13 ± 3% VO2peak ) were significantly lower for the non-disabled subjects than those with paraplegia. Conclusion: Sedentary individuals with paraplegia are more capable of oxidizing fat during voluntary arm ergometry than non-disabled individuals perhaps due to local adaptations of upper body skeletal muscle used for daily locomotion. However, carbohydrate is the predominant fuel source oxidized across a wide range of intensities during voluntary arm ergometry in those with paraplegia, while WBFO is limited and maximally achieved at low exercise intensities compared to that achieved by able-bodied individuals during leg ergometry. These findings may partially explain the diminished rates of fat loss imposed by acute bouts of physical activity in those with paraplegia.