Author(s): PANAYIOTOU, G., DIAMANTI, V., LADAS, A., METHENITIS, S., DOULIGERIS, A., FEIDANTSIS, K., BELLALI, T., Institution: EUROPEAN UNIVERSITY OF CYPRUS, Country: CYPRUS, Abstract-ID: 2358

INTRODUCTION:
Heart rate recording is essential for determining acute and chronic exercise responses during rest and exercise and can be utilised as an internal load metric for exercise load monitoring. The present study examined the validity of different heart rate measurement methodologies during aerobic and resistance exercise under different intensities: 60% - 100% HRmax and 1 RM during aerobic and resistance exercise, respectively.
METHODS:
Thirty male sports science students, aged 22.7+1.6 years, with body mass 74.0±9.2 kg and height 1.77.4±6.8 m, participated in the study. After initial familiarisation, aerobic capacity (VO2max) and maximal strength (1RM) were measured seven days apart during two laboratory visits. Through a cross-over design, participants took place in an interval, incremental, multistage maximum aerobic and resistance exercise separated by one week. Aerobic exercise consisted of five stages of three minutes of treadmill running at 60%, 70%, 80%, 90% and 100% of HRmax, whereas resistance exercise involved five maximal repetition sets at 60%, 70%, 80%, 90% and 100% of 1 RM. Two minutes rest interval between stages/sets allowed recovery and simultaneous monitoring of HR through photoplethysmograph (PPG -hand finger pulse oximetry and wrist smart watch), electrocardiographic activity (one lead chest heart rate band and 12 lead ECG) and wrist palpation of the radial artery. All HR monitoring methods were compared against the criterion method of 12 lead ECG. Pearson correlation coefficient (r) was determined using IBM SPSS Statistics v29 software. The level of significance (p) was set at 0.05.
RESULTS:
Pearson correlation coefficient (r) of different methods and intensities concerning the criterion method of 12 lead ECG during endurance and resistance exercise ranged from r=0.075 (p>0.05) to r=0.923 (p<0.001) and r=0.28 (p>0.05) to 0.958 (p<0.001) respectively. In particular, higher correlations with 12 lead ECG during aerobic exercise were observed during moderate (70% HRmax) intensities with the one lead chest heart rate band (r=0.923, p<0.001). At the same time, the exact method revealed the lowest correlation during maximal (100% HRmax) intensity (r=0.075, p>0.05). In contrast, during resistance exercise, the highest correlations were shown during high (80% 1RM) intensity with the one lead chest heart rate band (r=0.028, p>0.05) and the lowest with the PPG (wrist smart watch) (r=0.923, p<0.001).
CONCLUSION:
An inversely dose-dependent validity pattern of heart rate recording emerged among different heart rate recording methods during aerobic and resistance exercise, likely to arise from technical and hemodynamic issues. Specifically, the validity of HR recording methods during aerobic exercise tends to decrease with increasing exercise intensity. In contrast, it increases during resistance exercise, with the reverse being the case with reducing exercise intensity.