Don't Put Your Heart at Risk When Exercising in Summer Heat

Rising temperatures and high humidity during summer months can cause not only performance loss for individuals exercising outdoors, but also place serious strain on the heart and circulatory system. During this period when running, cycling, walking and outdoor fitness training intensify, understanding the body's physiological response to heat becomes critically important.

Uzm. Dr. Yusuf Altınkaynak, Cardiologist at Batıgöz Sağlık Grubu Balçova Surgical Medicine Centre, points out that unconscious exercise in hot weather can increase heart rate, disrupt fluid-electrolyte balance, and create conditions for serious health problems in at-risk individuals.

Why Does the Heart Tire More Quickly? The "Blood Distribution Battle"
Uzm. Dr. Yusuf Altınkaynak, noting that during sports in hot and humid weather the body enters into a hidden struggle, summarizes the process as follows:

"While muscles continue to contract in hot weather, the body directs blood flow toward the skin to maintain internal temperature balance and enable cooling. The increase in blood pumped to the skin reduces the amount of oxygen reaching the actively working muscles. The heart must work far faster and more intensely than normal to both nourish the muscles and cool the body. This situation, particularly in hot weather, can multiply the load on the heart, creating conditions for early fatigue and cardiac arrhythmias."

Pay Attention to Heat Stress Index: Critical Threshold 32°C
Uzm. Dr. Yusuf Altınkaynak, emphasizing that high temperature combined with humidity can create a vital risk, stresses that when the perceived temperature exceeds 32°C (90°F), outdoor activities should be limited and, if possible, moved to indoor, air-conditioned spaces with ideal temperature. However, even in indoor spaces, care should be taken that air conditioning does not blow directly on the body and the environment is not excessively cooled.

Exercising During Midday Hours Can Create Risk
Timing exercise selection is critically important during summer months. Physical activity conducted during hours of intense solar radiation can significantly increase the body's heat load.

For this reason, exercise should be done during:
•    Early morning hours,
•    Cool time periods near sunset
are considered more appropriate.

If exercising outdoors, shaded areas should be preferred as much as possible, and direct sun exposure for extended periods should be avoided.

Golden Rules for Healthy Summer Training
Uzm. Dr. Yusuf Altınkaynak recommends following these fundamental steps to continue exercise routines safely during summer months:

•    Correct Time Window: Exercise should absolutely not be done between 11:00 - 16:00 when solar rays are most direct. Exercise should preferably be done before 09:00 in the morning or during evening coolness, with shaded routes selected in outdoor spaces.

•    Fluid and Electrolyte Balance: Daily consumption should be based on a minimum of 2.5 litres of water. Fluid intake should begin 20 minutes before training without waiting for thirst sensation, and small sips of water should be consumed every 10 minutes during exercise. Replenishing minerals such as sodium, potassium and magnesium lost through heavy sweating prevents dehydration and related rhythm problems. It should be remembered that sudden weight drops after training are due to water and mineral loss, not fat loss.

•    Gradual Adaptation (Heat Acclimatization): A gradual 7 to 14-day adaptation period should be allowed for the body to adjust to hot weather. During this period, training intensity and duration should be intentionally kept low.

•    Smart Cooling and Proper Clothing: Drinking cold water before training creates a heat buffer by balancing body temperature. During exercise, instead of sweat-trapping cotton fabrics, breathable porous synthetic fabrics and light, well-ventilated shoes should be preferred.

Stop Immediately When You Feel These Symptoms!
Cardiology Specialist Uzm. Dr. Yusuf Altınkaynak, noting that correctly reading signals sent by the body during exercise can be life-saving, concludes with vital warnings:

"If dizziness, nausea, extreme fatigue, blurred vision, chest tightness or cold sweating is experienced during exercise, training must be stopped immediately, the body must be moved to a cool area and body temperature reduced. Particularly individuals with chronic conditions such as heart failure, high blood pressure and diabetes should consult a specialist physician before planning an exercise routine in hot weather and undergo cardiovascular evaluation."