The relationship between heart rate variability and swimming speed

Heart rate variability can predict sports performance but is underused because its measurement is difficult. In the last five years, many companies have tried to make this measurement both easy to perform and very practical for coaches. In this study, 10 elite swimmers aged between 12 and 14 years were observed for 21 days. All swimmers were ranked in the first two places at the Romanian National Championships in at least one swimming event. In this period, they performed three speed tests at a 10-day interval. The speed test consisted of four repetitions of 50-meter freestyle, with a rest period of 5 minutes. Heart rate variability was measured every morning on the swimming deck just before practice. For this measurement, a very easy-to-use device was used, namely ithlete Finger Sensor, a photoplethysmography that was attached to a mobile phone and, after 55 seconds of measurement, the device provided an easy-to-interpret value. The relationship between heart rate variability measurements and swimming speed was interpreted. It was demonstrated that the results obtained for heart rate variability influenced the swimming speed results with a p-value < 0.001. This is one of the first studies to focus on how speed will depend on the measurement of heart rate variability just before the training session. For this reason, we cannot compare our results with those obtained in other studies. The current study also has some limitations, and one of the most important is the small number of participants.