Environmental conditions can significantly affect your performance. At altitude and in hot, humid conditions, your body has to work much harder than usual to achieve performance similar to that in comfortable conditions.
However, challenging conditions can also trigger a natural adaptation process. Acclimation is the physiological transition that helps you improve performance in new, harsher conditions.
Certain Garmin devices can automatically detect when you are at altitude or exercising in a hot environment. Heat and altitude acclimation data is based on activities performed above 800 m and 22 °C. Environmental information is provided from GPS data and weather forecasts from your compatible smartphone.
Your body doesn't change overnight. Acclimation takes time, and you need to spend enough time in the new environment. Once you leave the harsh conditions behind, your body returns to its normal state. Your Garmin device understands this process, links environmental and performance data, and shows your current acclimation status. Keeping an eye on it helps you manage your expectations and performance goals.
The accuracy of your training data is ensured by automatically detecting and accounting for environmental conditions and performance metrics. If you can't hold your usual pace during a heatwave, it doesn't necessarily mean your cardiorespiratory fitness (VO2 max) has declined. Likewise, laboured breathing while hiking in the mountains doesn't mean your training has been unproductive.
How long does it take to acclimate to heat and humidity?
How quickly your body adapts depends on several factors. One of the most important is the difference between your usual environment and the conditions you need to adapt to. The greater the change, the longer acclimation takes. It also depends on the frequency and duration of your training.
Evidence shows that spending extended time in challenging climatic conditions every day provides the necessary acclimation within one to two weeks. Athletes with higher VO2 max values typically adapt to challenging climates faster – in some cases, the acclimation period is half as long.
Specific features of heat acclimation
Athletic performance involves converting the energy found in proteins, carbohydrates and fats. This in turn produces heat. During intense physical activity, your body produces as much heat as a 1000 W heater. Getting rid of excess heat is necessary to maintain a normal body temperature.
Circulation beneath the skin allows heat to dissipate. The natural cooling process becomes more effective when you sweat, as evaporating sweat has a cooling effect on your skin.
Not surprisingly, it is much easier for your body to get rid of excess heat on a cool, crisp morning than on a hot, humid summer afternoon. The surrounding environment has a very important effect. Heat acclimatisation focuses on your body's ability to effectively enhance its natural cooling systems.
This includes changes that allow you to sweat more and faster. It also includes changes that allow blood to flow faster beneath the skin. Other important changes include cardiovascular and electrolyte balance adjustments that add stability and help you tolerate the increased stress of hydration/dehydration cycles.
Specific features of altitude acclimation
At an altitude of 3000 m, oxygen levels are only 70% of those at sea level. This means your heart, lungs and circulation have to work much harder at altitude to deliver the same amount of oxygen to your muscles for aerobic energy.
Altitude-induced changes are mainly related to increased lung capacity and a greater number of oxygen-carrying red blood cells in circulation. Pressure in the pulmonary arteries increases, so blood flow reaches parts of the lungs that are usually not used at low altitude. With every heartbeat, the additional red blood cells deliver more oxygen to your muscles than usual.
These performance-enhancing changes don't disappear immediately when you return to lower altitudes, which is why athletes train at altitude.
