I’m doing St. Croix this year and figured I would start doing Hot Yoga to get acclimated early and keep going. I wanted to know how long you acclimatize for and how long til after you lose it? After reading this and doing some searches I came across this article: http://www.rotc.usaac.army.mil/forms/Heat_Acclimatization_Guide.pdf
How do you become heat acclimatized?
a. Heat acclimatization occurs when repeated heat exposures are sufficiently stressful to elevate body temperature and provoke perfuse sweating. Resting in the heat, with limited physical activity to that required for existence, results in only partial acclimatization. Physical exercise in the heat is required to achieve optimal heat acclimatization for that exercise intensity in a given hot environment.
Table 1. Benefits of Heat Acclimatization
Thermal Comfort – Improved
Exercise Performance – Improved
Core Temperature – Reduced
Sweating – Earlier & Greater
Skin Blood Flow - Earlier
Body Heat Production – Lower
Heart Rate - Lowered
Thirst - Improved
Salt Losses (sweat and urine) – Reduced
Organ Protection - Improved
3 Heat Acclimatization Guide
b. Generally, about two weeks of daily heat exposure is needed to induce heat acclimatization. Heat acclimatization requires a minimum daily heat exposure of about two hours (can be broken into two 1-hour exposures) combined with physical exercise that requires cardiovascular endurance, (for example, marching or jogging) rather than strength training (pushups and resistance training). Gradually increase the exercise intensity or duration each day. Work up to an appropriate physical training schedule adapted to the required physical activity level for the advanced military training and environment.
c. The benefits of heat acclimatization will be retained for ~1 week and then decay with about 75 percent lost by ~3 weeks, once heat exposure ends. A day or two of intervening cool weather will not interfere with acclimatization to hot weather.
How fast can you become heat acclimatized?
a. For the average soldier, heat acclimatization requires about two weeks of heat exposure and progressive increases in physical work. By the second day of acclimatization, significant reductions in physiologic strain are observed. By the end of the first week and second week, >60 percent and ~ >80 percent of the physiologic adaptations are complete, respectively. Soldiers who are less fit (APFT run times >15 min) or unusually susceptible to heat may require several days or weeks more to fully acclimatize.
b. Physically fit soldiers (APFT run times <14 min) should be able to achieve heat acclimatization in about one week. However, several weeks of living and working in the heat (seasoning) may be required to maximize tolerance to high body temperatures.
Looks like 2 straight weeks of daily heat exposure would be sufficient. Does anyone know if a long term approach exists? Would Hot Yoga twice a week for 4 months do the same thing?