Salt and trace element balance during exercise in hot and humid environments.

JRCT ID: jRCT1020230023

Registered date:12/09/2023

Basic Information

• Recruitment status: Recruiting
• Health condition(s) or Problem(s) studied: Heat related illness
• Date of first enrollment: 10/09/2023
• Target sample size: 32
• Study type: Interventional

Intervention(s)

At the Hyalchi Kichijoji Studio's Yoga & Stretch Room, exercise is conducted by maintaining a constant temperature and humidity (temperature: 30-35 degrees Celsius, humidity: 25-35%). This exercise involves stepping up and down on a 20cm-high step platform to the rhythm of a metronome set at 100 BPM. It includes alternating periods of exercise and rest (15 minutes of exercise followed by 10 minutes of rest for a total of 3 sets), during which participants are allowed to freely consume room-temperature beverages. The beverages used are mineral water (Suntory Natural Water), deep ocean water (Daido Dried Mew), and sports drinks (Pocari Sweat), with separate trials for each type of beverage. Exercise load tests are conducted with a gap of one week or more between sessions.
- During exercise, participants wear vital sensors to measure skin temperature and heart rate over time.
- Body weight measurements are taken before and after exercise to determine sweat loss by comparing it with fluid intake.
Due to the possibility that sufficient acclimatization to heat may not be achieved during the winter and the lack of sufficient evidence regarding whether acclimatization formed during the summer is maintained when exercise is continued in the winter, exercise load tests are conducted within the period when the Ministry of the Environment issues heatstroke alerts (in the 2023 fiscal year, from April 26th to October 25th).

Outcome(s)

Primary Outcome

The primary evaluation parameter is the concentration of mineral components in sweat.
The mineral components analyzed include sodium (Na), potassium (K), magnesium (Mg), calcium (Ca), zinc (Zn), copper (Cu), chromium (Cr), bromine (Br), and strontium (Sr).
The composition and quantity of electrolyte loss from the entire body are estimated based on changes in body weight and fluid intake.

Secondary Outcome

Secondary evaluation parameters include urine samples collected before exercise, heart rate during exercise, and temperature measurements taken during breaks.
Using the BDHQ (Brief Diet History Questionnaire), the estimated intake of trace elements from regular dietary habits is assessed.
The previous day's salt intake is measured from the urine samples collected before exercise.
Analysis is conducted to explore the relationship between heart rate during exercise, changes in body temperature, and the components of sweat.
Additionally, analyses are performed to examine the relationship between regular dietary intake patterns and the composition of sweat, as well as the relationship with fluid intake.

Key inclusion & exclusion criteria

• Age minimum: >= 20age old
• Age maximum: <= 40age old
• Gender: Male

Include criteria

1. Individuals who are 20 years of age or older but not older than 40 years at the time of obtaining consent.
2. Healthy males.
3. Those who have provided consent to participate in this research study.

• Exclude criteria: Individuals currently receiving outpatient treatment for diabetes, hypertension, heart disease, or renal insufficiency, individuals receiving outpatient care for psychiatric disorders, and individuals whose recent health examination results, confirmed with their consent, show blood pressure or blood glucose levels exceeding the reference range. Additionally, individuals who have been advised by a physician to refrain from exercisin

Related Information

• Primary Sponsor: kAKAMU Takeyasu