Does Arterial Health Affect V˙O2peak and Muscle Oxygenation in a Sedentary Cohort?

PURPOSE: An association between arterial health and peak oxygen consumption (V˙O2peak) has been demonstrated, however little is known about how arterial health influences muscular oxygenation during exercise. The aim of this study was to gain insight into the relationships between arterial health, V˙O2peak and muscle oxygenation in a middle-aged sedentary population.

METHODS: Radial augmentation index (AIx; via Pulse Wave Analysis) of 21 sedentary, middle-aged participants (15 females, 6 males; age: 54.7 ± 5.4; BMI: 29.0 ± 4.7, mean ± SD) was assessed, and on another day (<7 days) participants completed a Modified Bruce Protocol (MBP). Using near infra-red spectroscopy, total oxygenation index (TOI) of the left flexor carpi ulnaris and the left vastus lateralis were monitored throughout the MBP. Independent and average (arm + leg) percentage decrease in TOI between stage 1 of the MBP and maximal exertion (TOIdiff) during MBP was calculated. Changes between dependent variables were correlated using Pearson product-moment correlations; interpreted as: r>0.5: strong, 0.5>r>0.3: Moderate; r<0.3: weak.

RESULTS: We observed a moderate negative correlation between AIx and V˙O2peak (r = -0.34, -0.63 to -0.03; Pearson correlation, 90% Confidence Limits), and a strong negative correlation between AIx and average TOIdiff (r = -0.58, -0.78 to - 0.27). The V˙O2peak and average TOIdiff were strongly correlated (r= 0.55, 0.23 to 0.77).

CONCLUSIONS: Arterial health appears to be an important determinant of muscle oxygenation during exercise. In turn, the muscle oxygenation during exercise is strongly related to the V˙O2peak. Developing training modalities to prioritise arterial health outcomes may be a useful way of improving V˙O2peak in this population.