Study design and participants
pain
MAY, COLD
This study was designed as a randomized controlled trial with parallel arms. Participants were recruited between May and July 2022 through social media and personal contacts. Eligibility criteria included (1) being male, (2) having no underlying health conditions, (3) not using antihypertensive or other cardiovascular medications, (4) not engaging in regular exercise training, (5) and not having prior experience with any of the components of the intervention (breathing, meditation, or cold exposure). A total of 42 participants (aged 26.7 ± 5.7 years; body mass index 22.8 ± 2.0 kg/mFlow-chart.All measurements were performed in a controlled environment at the Physiology Lab of the Institute of Sports Science at the University of Bern. The measurements were carried out by trained study staff under controlled conditions using the same equipment and procedure. The participants visited the lab on two occasions for baseline and follow-up measurements, with both sessions taking place at similar times of the day to rule out circadian influences on outcomes. The participants were instructed to visit the lab at least 4 h postprandial and to avoid consuming caffeinated or alcoholic beverages and nicotine for 4 h prior to the measurements. They were further advised to abstain from vigorous physical activity for at least 24 h before each test day.The study protocol included the administration of questionnaires to obtain information on the participants’ demographics, medical history, habitual physical activity, perceived stress, affect, and vitality. Subsequently, heart rate (HR), HRV and BP readings were conducted. Finally, a cold pressor test was performed to assess HR, BP responses, and perceived pain.After baseline assessments, the participants were randomly allocated to either the intervention group (IG) or the control group (CG) by the principal investigator using a computer-generated random number table. The IG participated in the WHM daily for 15 days while the CG continued with their normal daily activities. During the intervention period, participants were asked to maintain their usual diet and physical activity patterns.