How to Protect Our Immune System During Summer Workouts?

Regular physical activity has many positive effects on the immune system, including reducing inflammation, regulating stress hormones, and enhancing the circulation of immune cells. However, summer heat, increased UV radiation, fluid loss, and intense training can overload the body, potentially leading to the opposite effect: a weakened immune defense. Fortunately, there are ways to support our immune system during summer exercise.

The Connection Between Summer Heat and the Immune System

High environmental temperatures put stress on the body. Heat stress activates the hypothalamic-pituitary-adrenal (HPA) axis, which increases cortisol levels — a hormone with immunosuppressive effects. Excessive heat and dehydration can also impair the protective function of mucous membranes, making it easier for viruses and bacteria to enter the body. During the 3–72 hours after an overly intense workout (the so-called “open window” period), susceptibility to infections increases — especially upper respiratory tract infections.

Staying Hydrated: The First Line of Defense

Proper fluid intake is essential to maintaining immune function. Dehydration impairs lymphatic circulation and white blood cell activity, and may reduce the protective capacity of the nasal and throat mucosa.

Recommendations:

• Drink at least 500 ml of water 2 hours before exercise, and then 150–250 ml every 15–20 minutes during activity, especially if it lasts over an hour.
• Replenish electrolytes (sodium, potassium, magnesium), especially during longer or more intense workouts or if you sweat heavily.

Avoiding Overtraining – Finding the Right Balance

Regular, moderate-intensity exercise strengthens the immune system, while excessive training can have the opposite effect. During the summer months, it is especially important to maintain gradual progression, allow for rest periods, and prioritize recovery.
Moderate training reduces, while excessive training increases the risk of infection.
Adequate sleep (7–9 hours), active recovery, and stress management significantly reduce immune overload.

The Role of Nutrients and Micronutrients

Vitamins and minerals are essential for the normal functioning of immune cells. Summer sports increase the body's need for antioxidants and anti-inflammatory nutrients.
Electrolyte supplementation should not begin only after you feel the first signs of cramping. By then, the body's systems may already be functioning suboptimally.
At Hammer Nutrition, we offer a range of solutions to meet all the key elements of fueling. One such product is ENDUROLYTES, which contains all vital electrolytes in optimal proportions: potassium, magnesium, calcium, manganese, and vitamin B6.

Key elements include:

• Vitamin C (antioxidant, immune cell activator): citrus fruits, bell peppers, berries.
• Vitamin D (produced through sun exposure, but deficiency can occur even in summer): fish oil, eggs, fortified dairy products.
• Zinc and Selenium (antiviral effects, immune modulation): nuts, seeds, seafood.
• Probiotics (supporting the microbiome): yogurt, kefir, fermented vegetables.

Hammer Nutrition's Digest Caps is a natural digestion support formula that helps relieve bloating and promotes efficient nutrient absorption.
Protection Against UV Radiation and Oxidative Stress
Excessive UV radiation not only harms the skin but also causes oxidative stress in the body, which can negatively affect immune function.
Protection tips:

• Exercise in the morning or late afternoon when the UV index is lower.
• Wear UV-protective clothing, hats, and sunglasses.
• Use sunscreen (at least SPF 30), especially when spending extended time outdoors.

Conclusion

Exercising during the summer months offers numerous benefits — if we pay attention to protecting our immune system. Staying hydrated, avoiding overtraining, replenishing micronutrients, and protecting against sun exposure are all key to ensuring that workouts remain health-enhancing. With conscious planning, we can support not only our athletic performance but also our overall health in the long term.

References:

• Gleeson, M. et al. (2011). Exercise, nutrition and immune function. Journal of Sports Sciences.
• Nieman, D.C. (2007). Exercise and immunity: The “open window” hypothesis. Journal of Applied Physiology.
• Walsh, N.P. et al. (2011). Position Statement Part One: Immune Function and Exercise. Exercise Immunology Review.