@techreport{oai:sapmed.repo.nii.ac.jp:00018339,
 month = {Mar},
 note = {Aerobic exercise is an excellent way to maintain good health, and marathons are a popular form of aerobic exercise. Studies that using spectral analysis of heart rate variability (HRV) to evaluate autonomic nervous activity have established HRV as an indicator of exercise intensity. HRV is analyzed in terms of four distinct frequency bands of spectral power: ultra-low (ULF), very-low (VLF), low (LF), and high (HF) frequencies. This study evaluated two male pacesetter marathon runners wearing Electrocardiogram leads monitored during a 30-km marathon in Japan. Time series data of the runners’ R-R intervals over 90 min showed that the spectral power values in ULF and VLF bands exceeded those in LF and HF bands. Others have reported that ULF and VLF power values decrease as cardiovascular disease severity increases. Accordingly, these values all have clinical prognostic potential for the evaluation of individuals’capacity for exercise.},
 title = {Ultra-low and very-low frequency components of power spectral density relative to heart rate variability during marathon running},
 year = {2023}
}