Cardiovascular and skeletal muscle health with lifelong exercise

Abstract

The purpose of this study was to examine the effects of aerobic lifelong exercise (LLE) on maximum oxygen consumption (V̇o_2max) and skeletal muscle metabolic fitness in trained women ( n = 7, 72 ± 2 yr) and men ( n = 21, 74 ± 1 yr) and compare them to old, healthy nonexercisers (OH; women: n = 10, 75 ± 1 yr; men: n = 10, 75 ± 1 yr) and young exercisers (YE; women: n = 10, 25 ± 1 yr; men: n = 10, 25 ± 1 yr). LLE men were further subdivided based on intensity of lifelong exercise and competitive status into performance (LLE-P, n = 14) and fitness (LLE-F, n = 7). On average, LLE exercised 5 day/wk for 7 h/wk over the past 52 ± 1 yr. Each subject performed a maximal cycle test to assess V̇o_2max and had a vastus lateralis muscle biopsy to examine capillarization and metabolic enzymes [citrate synthase, β-hydroxyacyl-CoA dehydrogenase (β-HAD), and glycogen phosphorylase]. V̇o_2max had a hierarchical pattern (YE > LLE > OH, P < 0.05) for women (44 ± 2 > 26 ± 2 > 18 ± 1 ml·kg^-1·min^-1) and men (53 ± 3 > 34 ± 1 > 22 ± 1 ml·kg^-1·min^-1) and was greater ( P < 0.05) in LLE-P (38 ± 1 ml·kg^-1·min^-1) than LLE-F (27 ± 2 ml·kg^-1·min^-1). LLE men regardless of intensity and women had similar capillarization and aerobic enzyme activity (citrate synthase and β-HAD) as YE, which were 20%-90% greater ( P < 0.05) than OH. In summary, these data show a substantial V̇o_2max benefit with LLE that tracked similarly between the sexes, with further enhancement in performance-trained men. For skeletal muscle, 50+ years of aerobic exercise fully preserved capillarization and aerobic enzymes, regardless of intensity. These data suggest that skeletal muscle metabolic fitness may be easier to maintain with lifelong aerobic exercise than more central aspects of the cardiovascular system. NEW & NOTEWORTHY Lifelong exercise (LLE) is a relatively new and evolving area of study with information especially limited in women and individuals with varying exercise intensity habits. These data show a substantial maximal oxygen consumption benefit with LLE that tracked similarly between the sexes. Our findings contribute to the very limited skeletal muscle biopsy data from LLE women (>70 yr), and similar to men, revealed a preserved metabolic phenotype comparable to young exercisers.

Keywords: aging; masters athletes; maximal oxygen uptake; metabolic health.

Fig. 1.

Study recruitment flowchart for female and male young exercisers (YE), lifelong exercisers (LLE), and old healthy (OH) participants. *Two of the 23 LLE men were not included in analysis because of different training background (weight training), providing for 21 LLE men.

Fig. 2.

Individual relative V̇o_2max data of young exercisers (YE), lifelong aerobic exercisers (LLE), and old healthy untrained individuals (OH) compared with normative values from the FRIEND database (n = 2,777) (28). The FRIEND database was used due to similar graded exercise test mode (cycle), and those data were generated from direct gas analysis rather than estimates. These values are compared with an estimated female-specific frailty threshold of 14 ml·kg⁻¹·min⁻¹ (10, 28, 37). Although this threshold has not been as well established in women as it is in men [(17.5 ml/kg/min; 5 metabolic equivalents (METs)] (37), this estimate may be the prognostic exercise capacity necessary for an independent lifestyle in women. Furthermore, failure to remain above this threshold may result in an increased risk for mortality as described by Myers et al. (37). FRIEND, fitness registry and the importance of exercise national database; V̇o_2max, maximal oxygen consumption.

Fig. 3.

Individual relative V̇o_2max data of young exercisers (YE), vigorous lifelong aerobic exercisers (LLE-P), fitness trained lifelong aerobic exercisers (LLE-F), and old healthy untrained individuals (OH) compared with normative values from the FRIEND database (n = 1,717) (28). The FRIEND database was used due to similar graded exercise test mode (cycle), and those data were generated from direct gas analysis rather than estimates. These values are compared with a male-specific frailty threshold of [(17.5 ml/kg/min; 5 metabolic equivalents (METs)], which has been established as the prognostic exercise capacity necessary for an independent lifestyle in men. Furthermore, failure to remain above this threshold may result in an increased risk for mortality as described by Myers et al. (37). FRIEND, fitness registry and the importance of exercise national database; V̇o_2max, maximal oxygen consumption.