International Journal of Sport, Exercise and Health Research 2025; 9(1): 5-10 ; DOI:10.31254/sportmed.9102
Comparing Power and Oxygen Uptake During Treadmill Exercise Testing in PWH and PWOH Hispanic Adults
Farah A. Ramírez Marrero1 , Carlos J. Rodríguez1 , José R. Quiñones-González2 , Ángel L. Pabón-Villafañe3 , Jorge Santana-Bagur3
1. University of Puerto Rico Río Piedras Campus, College of Education, Department of Graduate Studies, San Juan, Puerto Rico
2. Department of Sports and Recreation, Government of Puerto Rico, Rio Piedras, Puerto Rico
3. University of Puerto Rico Medical Sciences Campus, San Juan, Puerto Rico
*Author to whom correspondence should be addressed.
Received: 5th March, 2025 / Accepted: 3rd June, 2025 / Published : 11th September, 2025
Background: Daily engagement in physical activity requires the capacity of skeletal muscle to generate power and utilize the oxygen needed for muscle power generation, concepts associated with mechanical and energy efficiency. People living with HIV (PWH) experience metabolic dysfunctions including reduced muscle mass, fat distribution changes known as lipodystrophy, and low capacity for oxygen uptake (VO2max), potentially affecting their mechanical and energy efficiency. Aims and Objectives: To evaluate and compare oxygen uptake (%VO2max) and power output at different stages during a treadmill exercise test in PWL with lipodystrophy (PWL-Lipo), PWL without lipodystrophy (PWL-NoLipo), and adults without HIV infection (PWOH). Materials and Methods: Hispanic adults (45 women, 43 men) of similar sex and age distribution: 29 PWH-Lipo (17 women, 12 men), 29 PWH-NoLipo (13 women, 16 men), and 30 PWOH (15 women, 15 men). Anthropometric measures of weight, height, percent body fat, and waist and hip circumference were obtained. Participants completed a graded exercise test on a treadmill until volitional fatigue using the modified Bruce protocol. To compare oxygen uptake (%VO2) and power output (W) between stages during the treadmill protocol, repeated measures ANOVA and Tuckey post hoc was used. Results: Differences by sex and group in power output and oxygen uptake during the treadmill exercise protocol stages were observed. While women in the three groups showed similar power in each protocol stage, men in the PWH-NoLipo group showed lower power output during the last stages of the protocol compared with the other groups of men. Percentage of VO2max was higher in each stage for men in the PWH-Lipo group compared with the other groups of men, and also higher in women in the PWH-Lipo group but only during stages 2nd and 3rd of the protocol, suggesting that there are lipodystrophy-associated metabolic dysfunction explaining a lower mechanical efficiency in all exercise intensities in men and during intermediate exercise intensities in women. Conclusion: Exercise intervention studies must consider and evaluate mechanical efficiency as a critical factor to explain improvements in functional capacity not only in PWH but also, in adults with metabolic complications and lipodystrophy, also reported in diabetes, hypertriglyceridemia, and liver disease.
Mechanical efficiency, Metabolic dysfunction, Modified Bruce protocol, HIV
