During incremental cycling exercise, the Heart rate/LF ratio was positively correlated with noradrenaline (ρ=0.788, p<0.05), blood lactate (ρ=0.802), and carbon dioxide production (ρ=0.903).
Cross-Sectional (n=15)
Does the heart rate to LF ratio reflect sympathetic nervous activity during incremental cycling exercise in healthy adults?
The heart rate to LF ratio is a valid heart rate variability-based index that reflects sympathetic nervous activity and metabolic responses during incremental exercise.
Effect estimate: ρ = 0.788
p-value: p=<0.05
ABSTRACT A low‐frequency to a high‐frequency component ratio (LF/HF) in heart rate variability (HRV) may not accurately reflect sympathetic nervous activity during exercise. Thus, a valid HRV‐based index of sympathetic nervous activity is needed. Therefore, the heart rate to LF ratio (Heart rate/LF) was evaluated as sympathetic nervous activity index which is reflected by catecholamine levels during incremental exercise. In this study, 15 healthy adults performed an incremental exercise test using a cycle ergometer. HRV was derived from electrocardiography and HRV components related to the autonomic nervous system were obtained using frequency analysis. Heart rate/LF was calculated using the heart rate and LF component produced by HRV analysis. Catecholamine, blood lactate levels and respiratory gas were also measured throughout the exercise test. While LF/HF did not increase with increasing exercise intensity, Heart rate/LF non‐linearly increased during the incremental exercise test, as did noradrenaline and blood lactate. Interestingly, Heart rate/LF values were positively correlated with noradrenaline ( ρ = 0.788, p < 0.05) and blood lactate ( ρ = 0.802, p < 0.05) levels and carbon dioxide production ( ρ = 0.903, p < 0.05) from at rest through the exercise stages. Heart rate/LF reflects sympathetic nervous activity and metabolic responses during incremental cycling exercise and has potential as an HRV index of sympathetic nervous activity during exercise. Trial registration: UMIN Japan identifier: UMIN000039639.
Tanoue et al. (Thu,) conducted a cross-sectional in Healthy adults (n=15). Incremental cycling exercise vs. Rest was evaluated on Correlation of Heart rate/LF with noradrenaline levels (ρ = 0.788, p=<0.05). During incremental cycling exercise, the Heart rate/LF ratio was positively correlated with noradrenaline (ρ=0.788, p<0.05), blood lactate (ρ=0.802), and carbon dioxide production (ρ=0.903).