Hr monitor

Participants were not endurance trained but practiced combat sports, horse riding, court sports, and recreational activities such as yoga and surfing. In addition to their normal activities and training, participants were asked to run for 1 h 3 times a week at 70% of HR_max for 6 weeks. Total training volume of the participants thus ranged 3–10 h per week, depending on their other recreational activities (3–5 days per week). A 1-day rest period between the endurance training sessions was predefined for regeneration and adaptation purposes. To ensure that participants followed training intensity protocols, HR monitors (Polar Electro GmbH) were provided. All participants completed the training protocol over the training period with high compliance, which covered all exercise activities, including the type of sport and its duration, as well as subjective exertion (Borg scale) to control and monitor all training and recreational exercise activities. Additionally, the training protocol enabled participants to control their individual progress at the predefined heart rate and running time. Exercise sessions were performed individually or in training groups having similar endurance capacity. In addition, a professional trainer was provided, who offered associated training such as training advice or individual training.

Sedentary subjects followed an exercise training intervention as previously reported.23 It consisted of a moderate‐intensity aerobic protocol of tri‐weekly supervised exercise sessions over 16 weeks. Each session was progressively increased from 30 to 60 min. Half of the training was performed on a stationary bike and the other half on a treadmill (mostly walking or some light jogging). Exercise intensity was progressive and adapted to each subject based on his or her peak HR to achieve 60–75% of the maximal HR deduced from the baseline V̇O₂peak test. Exercise prescription was adapted at the midpoint of the intervention with a submaximal ergometer test as described in details by Dubé et al.24 HR monitors (Polar Electro Oy, Kempele, Finland) and exercise logs were utilized to monitor intensity.

The study participants underwent a 12-week treadmill walking intervention (44 total sessions). All exercise sessions were supervised by a certified personal trainer or exercise physiologist. No more than two individuals participated in each exercise session. Each walking exercise session lasted for 30 min and was administered 4 sessions/week in local recreation centers. To assess exercise intensity, HR monitor (Polar Electro, Kempele, Finland) and RPE scale [30 ] were used during exercise, with the goal of achieving a moderate intensity during each session. The exercise session intensity, session duration, and weekly frequency were gradually increased during the first 4 weeks until participants were walking 30 min per session (4 sessions/week). During the 5–12 weeks, the exercise intensity was targeted at 50–60%of HRR and exercise duration was 30 min. To tailor exercise intensity for each participant, the treadmill speed and grade were modified each session based on HR and RPE based on individual baseline exercise capacity. A 10 min warm-up and 10 min cool-down consisted of light walking and flexibility exercise were administered before and after each session. Thus, total exercise session length was 50 min including warm-up and cool-down.

The study participants completed a 12-week treadmill walking intervention. A certified personal trainer or exercise physiologist supervised all exercise sessions in local recreation centers. Each session lasted 30 min and occurred four days per week. A HR monitor (Polar Electro, Kempele, Finland) and the RPE scale [40 ] were used during each exercise sessions to monitor the intensity of the exercise and to maintain a moderate intensity. The exercise session intensity, duration, and weekly frequency were increased gradually across the first month until participants were walking 30 min per session (4 days per week). During the remaining (5–12) weeks, the exercise intensity was targeted at 50–60% of HRR and exercise duration was 30 min (a total of 44 sessions for 12 weeks), plus a 10-min warm-up and 10-min cool-down (50 min total). The treadmill speed and grade were modified each session based on each participant’s progress and exercise capacity. The proportion of sessions attended was used to assess compliance to the intervention protocol.