Relationships Between Strength, Cardiorespiratory Fitness, And Functional Aerobic Impairment In Brazilian Males Living With HIV

With strong supporting literature, it has been universally accepted among public health leaders all over the world that increased fitness improves health, quality of life, and reduces the risk of all-cause mortality. PURPOSE: The purpose of this investigation was to examine the relationships between strength, cardiorespiratory fitness (VO2max), and evidence of functional aerobic impairment (FAI) in a sample of people living with HIV in Brazil. METHODS: All participants completed a VO2max test on a cycle ergometer and maximum voluntary contraction (MVC) test that was determined by measuring isometric leg strength in a seated position with a load cell coupled to computer software on separate days >72 hours. FAI was determined using the percent difference between observed max VO2 to that of their age-predicted VO2 using a regression equation created from the Brazilian national registry data specific to a maximal cycle ergometer test. A Pearson's correlation was carried out between the VO2max and MVC measurements. Comparisons were also made between the VO2max obtained in the test and the VO2max predicted for age by equation using a one-sample t-test. RESULTS: A total of 19 men living with HIV (age: 40 ± 12; BMI: 23.7 ± 4.02) participated in this cross-sectional study. VO2max showed a significant correlation with MVC leg strength (0.614; p < 0.05). The t-test showed a significant difference when comparing the measured VO2max with the predicted VO2max: (30.8 ± 5.48 vs 35.7 ± 4.76; p < 0.001) with a large effect size (d = -1.85). CONCLUSION: Leg strength and VO2max performed on a cycle ergometer exhibited a positive relationship indicating one component of fitness, such as strength, could positively influence cardiorespiratory fitness (VO2max) in this population and vice-versa. Further, these data agree with previously published data that show males living with HIV often present FAI, possibly due to a sedentary lifestyle and/or disease related fatigue. Exercise prescriptions tailored for the HIV community should include combination aerobic and resistance training for optimal benefits. Caution should also be taken when prescribing exercise with this population and should be initiated at a light intensity below the current recommendations for the general population due to the FAI often observed among people living with HIV. JAM and PW were financed in part by a scholarship from the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Brazil - finance code 001.