Effects of sodium nitrite supplementation on exercise capacity in middle‐aged and older healthy adults (LB689)

Abstract

Declines in exercise capacity with aging are associated with increased risk of disability and mortality. Dietary interventions that increase circulating nitrite may improve exercise capacity. We performed a pilot study to assess the effects of chronic oral sodium nitrite supplementation (NS) on incremental treadmill exercise performance (modified Balke protocol) in sedentary and recreationally‐active middle‐aged and older (MA/O) healthy adults (n=26, 62±2 yrs). Subjects abstained from dosing for >12 hr before exercise. NS increased plasma nitrite and nitrate (p<0.01). Peak exercise respiratory exchange ratio (RER), heart rate (HR) and ratings of perceived exertion (RPE), markers of voluntary effort, did not differ pre‐post treatment in any group after 10 weeks of NS (80 or 160 mg/d capsules, TheraVasc, Inc., randomized, placebo‐control, double‐blind). NS did not influence maximal oxygen consumption (VO2) (Pl: ‐0.55 ± 2.01; 80mg: 0.41 ± 1.69; 160mg: ‐0.11 ± 1.19 ml/kg/min, p=0.63), although there was a trend for improvement in exercise duration (Pl: ‐0.3 ± 20.0 s; 80mg: +40.9 ± 65.5 s; 160mg: +18.6 ± 28.4 s, p=0.16). There were no significant effects of NS on VO2, HR, RER, RPE or minute ventilation during standardized submaximal workloads. These preliminary results suggest that NS may not increase aerobic exercise capacity or modify responses to submaximal exercise in healthy normally active MA/O adults. It is possible, however, that NS may improve exercise capacity or favorably modify submaximal exercise responses in adults with greater baseline nitrite deficiency (e.g., patients with clinical disease).Grant Funding Source: Supported by NIH HL107105, RR025780, AG000279