Clinical trial NCT04556422: Comparison of Acute Sauna With Exercise and Sauna
Official title: Standalone Sauna Versus Exercise Followed by Sauna on Cardiovascular Function in Non-naïve Sauna Users
Study type: INTERVENTIONAL
Overall status: COMPLETED
Phase: NA
Conditions: Cardiovascular Risk Factor
Blood Pressure
Arterial Stiffness
Keywords: Sauna bathing
Aerobic exercise
Thermal therapy
Passive heat
Lead sponsor: University of Jyvaskyla
Sponsor class: OTHER
Collaborators: name: Finnish Foundation for Cardiovascular Research
name: Business Finland
name: Harvia Finland Oy
First posted: 2020-09-21
Enrollment: 72
Sex: ALL
Minimum age (years): 30
Maximum age (years): 75
Standard ages: ADULT
OLDER_ADULT
Accepts healthy volunteers: no
Allocation: NON_RANDOMIZED
Intervention model: CROSSOVER
Primary purpose: BASIC_SCIENCE

Brief summary: Sauna bathing has been associated with a lower risk for cardiovascular disease (CVD) outcomes, improved vascular endothelial and cardiac function, reduced oxidative stress and lower blood pressure. Earlier studies conducted by the investigators have showed positive alterations of arterial stiffness and hemodynamics through sauna bathing.

Some studies have sought to utilize sauna bathing as an intervention after exercise with promising and synergistic results, although the effects on populations with cardiovascular risk factors are less clear. Furthermore, studies investigating the use of both exercise and sauna bathing in combination has been somewhat limited. However, results from some studies speculate that adjunctive exercise and sauna interventions may be useful for aging and clinical patient population groups.

Given that heat therapy and sauna use is gaining more worldwide popularity, the investigators sought to compare the acute hemodynamic effects between sauna use alone and a short bout of exercise followed by sauna exposure. It was hypothesize that the combination of exercise and sauna will elicit greater changes than sauna alone. To achieve this, we standardized the protocol duration (30 minutes).

Detailed description: In this crossover trial, all study participants underwent two interventions, each on a separate occasion (\>72 hours apart). A standalone 30-minute sauna at 75°C (S), and 15-minutes of cycling on the stationary bike at 75% maximum heart rate, followed by 15-minutes of sauna exposure (ES). A cycling exercise test was conducted on a separate day prior to the experiment to ascertain individual maximal exercise heart rates, which was then used to calculate individual 75% maximum.

After the ﬁrst 15-minute period of S, the participants left the sauna room to have a quick shower (\<30 seconds) before going back for the second 15-minute period. The same sauna bathing room (75°C) was used for all participants and the cycling exercise was conducted within 10 meters of the sauna room to minimize transit time during ES. Participants were instructed to abstain from eating 2h, caffeine 12h and alcohol 24h prior to the measurements. Food intake was not standardized. Fluid was consumed ad libitum. A medical physician was in attendance at all times and participants were allowed to leave the sauna or stop the experiment at any time if they felt uncomfortable.

Brachial blood pressures and pulse wave velocity (PWV) as a measure of arterial stiffness, were taken in their respective order at three different time points; before (PRE), immediately after (POST), and after a 30-minute recovery (POST30). Transit time from the cessation of the intervention to POST measurements were kept under 60 seconds. All measurements were performed by the same assessor to minimize ascertainment biases.

Participants were permitted to take a quick shower (\<30 seconds) before POST measurements were taken. Water temperature or the shower was not controlled and participants could freely select their desired temperature. Thereafter, they were instructed to rest in a designated waiting lounge (mean temperature 21°C) in a seated position for a duration of 30-minutes before the last measurement (POST30) was taken.

Eligibility criteria: Inclusion Criteria:

* Free of a prior diagnosis of CVD, exhibits at least one of the following cardiovascular risk factors: a history of smoking, hyperlipidemia, hypertension, diabetes, obesity, or family history of coronary heart disease (CHD).

Exclusion Criteria:

* recent musculoskeletal injuries or surgery (less than 6 months ago), mental illnesses, under 30 years of age or over 75 at time of recruitment, health conditions that may contraindicate study parameters.

Primary outcomes:
measure: Brachial blood pressure
timeFrame: Single session (30 minutes)
measure: Central blood pressure
timeFrame: Single session (30 minutes)
Secondary outcomes:
measure: Arterial Stiffness
timeFrame: Single session (30 minutes)
measure: Augmentation Index
timeFrame: Single session (30 minutes)
Other outcomes:
Locations:
city: Jyväskylä
country: Finland
facility: University of Jyväskylä
state: Keski-Suomi
Study officials:
affiliation: Central Finland Central Hospital
name: Jari A Laukkanen, PhD/MD
role: PRINCIPAL_INVESTIGATOR
References:
citation: Lee E, Laukkanen T, Kunutsor SK, Khan H, Willeit P, Zaccardi F, Laukkanen JA. Sauna exposure leads to improved arterial compliance: Findings from a non-randomised experimental study. Eur J Prev Cardiol. 2018 Jan;25(2):130-138. doi: 10.1177/2047487317737629. Epub 2017 Oct 19.
citation: Laukkanen T, Kunutsor SK, Zaccardi F, Lee E, Willeit P, Khan H, Laukkanen JA. Acute effects of sauna bathing on cardiovascular function. J Hum Hypertens. 2018 Feb;32(2):129-138. doi: 10.1038/s41371-017-0008-z. Epub 2017 Dec 21.
citation: Lee E, Willeit P, Laukkanen T, Kunutsor SK, Zaccardi F, Khan H, Laukkanen JA. Acute effects of exercise and sauna as a single intervention on arterial compliance. Eur J Prev Cardiol. 2020 Jul;27(10):1104-1107. doi: 10.1177/2047487319855454. Epub 2019 Jun 8. No abstract available.