2.2. Intervention
Participants in the intervention group participated in a 16-week aerobic training program on a conventional motorized treadmill, for three sessions per week, consisting of a warm-up (10–15 min), 35–50 min treadmill exercise (increasing 5 min each four weeks) at a work intensity of 50–65% of peak heart rate (increasing by 5% every four weeks) measured during a previous maximal treadmill test, and cooling-down (5–10 min). In order to ensure that the training workload was appropriate during the entire session, all participants from the intervention group wore a wireless wearable heart rate monitor (Sport Tester PE3000, Polar Electro, Kempele, Finland).