Association Between Change in Nonexercise Estimated Cardiorespiratory Fitness and Mortality in Men.

Objective: To examine the association between change in nonexercise estimated cardiorespiratory fitness (eCRF) and mortality risk in adult men. Patients and Methods: A total of 10,445 men (mean age, 44.6±9.3 years) from the Aerobics Center Longitudinal Study underwent 2 comprehensive medical examinations and peak work rate tests between January 1, 1979, and December 31, 2002, with an average time between measures of 5.7±4.9 years. Participants were observed for 11.6±6.4 years after their second examination until death or December 31, 2003. The eCRF was calculated with the Jackson et al (2012) and Nes et al (2011) published nonexercise estimation equations. Cox proportional hazards models were performed to examine the association between change in eCRF and all-cause and cardiovascular disease (CVD) mortality. Results: There were 601 deaths (192 CVD deaths) during the follow-up period. For both eCRF equations, a higher eCRF at baseline was associated with significant reductions in mortality risk from all causes and CVD (P<.001). Change in eCRF by the Jackson equation remained significantly associated with all-cause mortality (P<.001) and CVD mortality (P=.02) after multivariable adjustment. Every 1 metabolic equivalent (3.5 mL·kg-1·min-1) increase in eCRF was associated with a 21% and 22% reduction in mortality risk from all causes or CVD, respectively. No significant associations were observed between change in eCRF by the Nes equation and all-cause (P=.69) or CVD (P=.85) mortality risk after multivariable adjustment. Conclusion: The association between change in nonexercise eCRF and mortality risk may be equation dependent.

Negative Energy Balance Induced by Exercise or Diet: Effects on Visceral Adipose Tissue and Liver Fat.

The indisputable association between visceral adipose tissue (VAT) and cardiometabolic risk makes it a primary target for lifestyle-based strategies designed to prevent or manage health risk. Substantive evidence also confirms that liver fat (LF) is positively associated with increased health risk and that reduction is associated with an improved metabolic profile. The independent associations between reductions in VAT, LF, and cardiometabolic risk is less clear. In this narrative review, we summarize the evidence indicating whether a negative energy balance induced by either an increase in energy expenditure (aerobic exercise) or a decrease in energy intake (hypocaloric diet) are effective strategies for reducing both VAT and LF. Consideration will be given to whether a dose-response relationship exists between the negative energy balance induced by exercise or diet and reduction in either VAT or LF. We conclude with recommendations that will help fill gaps in knowledge with respect to lifestyle-based strategies designed to reduce VAT and LF.