THE LINK BETWEEN HEART RATE VARIABILITY AND ENDURANCE IN SWIMMING

Heart rate variability is a relatively new measurement in sport that can predict sport performance. Unfortunately, it is underused because usually it is not simple to measure it. In the last years, because of the increase of the investment in sport, many companies tried to make different devices to make this measurement easier. In this study, for 21 days, 10 elite swimmers aged between 12 and 14 years old were observed. All the swimmers are experienced ones, being ranked in the first 2 places at Romanian National Championships in at least one swimming event. In this period, they performed 3 endurance tests, at a 10-day interval. The endurance test consisted of a 30 minutes continuous swimming at maximum speed, these tests being named T-30. Heart rate variability was measured in every morning, right before practice, on the swimming deck. For this measurement was used a very easy to use device, iThlete, a photoplethysmography which was attached to a mobile phone. The time needed for measurement is only 55 seconds and the value is very easy to interpret. The link between swimming endurance and the heart rate variability measurement was interpreted. The results showed us that heart rate variability influenced the results in swimming endurance with a p-value<0,001.