The colder season has started and some of us often have to struggle with colds and sore throats, especially in the winter months. Acute infections of the upper respiratory tract, such as colds, coughs, sinus, middle ear and tonsillitis are among the most common diseases of all age groups. There can be different causes or triggers behind this. We looked at which ones.
The scope and intensity of physical exertion also influence the risk of infection of the upper respiratory tract (abbreviation: URTI). According to epidemiological data, endurance athletes are at increased risk of infection during periods of hard and intense training (Nieman, 1997). The so-called "J-shaped model", which shows the connection between the risk of infection of the upper respiratory tract and physical or sporting stress levels, has become established in the world of experts:
Moderate, regular physical activity appears to reduce susceptibility to upper respiratory tract infection compared to an inactive lifestyle. On the other hand, athletes are exposed to an increased risk during an intensive training phase or hard stress units, including in particular physical overload or overtraining.
Possible reasons for an increased risk of infection during hard training sessions
Research shows that the level of physical activity affects and alters our immune function differently and this is likely to have an impact on upper respiratory tract infection susceptibility. There are various reasons and scientific approaches for a reduced immune system in connection with an intensive exercise unit. One 'mechanism' is negative energy balance or low carbohydrate availability (eg depleted glycogen stores) which causes our body to 'stress', especially during intense exercise or competitions lasting several hours.
Long, hard cycling sessions can therefore weaken the function of the immune system, as shown in the following simplified graphic:
Many are also familiar with the so-called "open window" theory: Scientists suspect that the body reacts more susceptible to microorganisms (especially viruses) due to changed immune parameters after exhausting stress and is therefore exposed to an increased susceptibility to infections (Pedersen & Ullum, 1994). . This potential "open window" of the changed immunity level or the time window of the increased risk of infections can be between three and 24 hours (in extreme situations even up to 72 hours).
Practical tips for triathletes to minimize the risk of infection:
- A balanced, varied and needs-based diet provides the body with sufficient energy and protein, important micronutrients (vitamins and minerals) and phytochemicals (substances that give plant-based foods colour, fragrance and aroma)
- Sufficient fluid intake during exercise and in the regeneration phase to minimize possible negative effects of dehydration (lack of fluids) on the immune function
- Consume carbohydrates before, during and after a long, hard workout: This prevents a drop in blood sugar and reduces the increase in certain stress hormones (e.g. cortisol, adrenaline) and cytokines in the blood plasma. This limits the stress-related "weakening" of the immune system
- Sufficient sleep (at least 7 hours per night)
- Avoid overtraining
- Never share personal drinking bottles, towels, etc. with other athletes
- Choose the right outdoor clothing
- Reducing personal “life stress” such as mental stress
