Research
Research projects and results
Asthma in Cross-Country Skiers
Asthma prevalence, diagnosis and treatment in competitive skiers
Asthma is one of the most common chronic diseases among athletes. We studied asthma and respiratory symptom prevalence in 351 competitive cross-country skiers compared with 338 population controls. The most successful athletes had the highest asthma prevalence, most often well-controlled with treatment.
Key findings:
- Asthma prevalence in skiers 25.9% vs controls 9.2% (p < 0.001) — Mäki-Heikkilä et al. 2021
- Later age at onset in skiers: median 13.0 vs 8.0 years — Mäki-Heikkilä et al. 2021
- 89% of skiers with asthma had well-controlled disease — Mäki-Heikkilä et al. 2021
- 82.4% used inhaled corticosteroids regularly — Mäki-Heikkilä et al. 2021
- Highest prevalence in the most successful skiers: 56.1% — Mäki-Heikkilä et al. 2022a
- Non-allergic asthma more common in skiers (60.1% vs 38.7%, p = 0.036) — Mäki-Heikkilä et al. 2022a
- Non-allergic asthma OR 5.05 (95% CI 2.65–9.61) — Mäki-Heikkilä et al. 2022a
Related publications: Systematic review (Sports Medicine 2020) · Prevalence study (SJMSS 2021) · Training volume and asthma (J Asthma 2022) · Review (Finnish Medical Journal 2024)
Athlete's Cough
Cough prevalence and impact in endurance sports
This study investigates cough frequency and impact during and after endurance exercise in winter conditions, particularly in cross-country skiers. We use a CE-certified SIVA MVP 1.0 cough monitor for objective cough monitoring. The aim is to describe exercise-induced cough and develop new treatment methods for athletes experiencing cold-induced respiratory symptoms.
Key findings:
- Post-exercise cough: skiers 60.6% vs controls 22.8% (p < 0.001) — Mäki-Heikkilä et al. 2023
- Prolonged cough was rare: skiers 2.0%, controls 4.8% — Mäki-Heikkilä et al. 2023
- Respiratory infections hamper training and competition especially in those with asthma — Mäki-Heikkilä et al. 2023b
- Skiers with asthma withdrew from competition more often (76.9% vs 62.2%, p = 0.011) — Mäki-Heikkilä et al. 2023b
- Individual infection duration: 5.0 vs 4.0 days — Mäki-Heikkilä et al. 2023b
- Total absent days per season: 15 vs 10 — Mäki-Heikkilä et al. 2023b
Related publications: Cough and respiratory symptoms (BMJ Open Sport & Ex Med 2023) · Respiratory infections (Int J Circumpolar Health 2023)
Why Does Asthma Develop in Athletes?
Exhaled air temperature and humidity in endurance athletes
Even under extreme conditions, our airways warm and humidify inhaled air. How does years of endurance training affect this process? We investigate exhaled air temperature and humidity in endurance athletes under extreme conditions using a custom-developed measurement device year-round in Finland.
The results will allow us to build a model to study how extensive endurance training predisposes to asthma — a long-standing question in sports medicine. Results may explain why some athletes are more susceptible to exercise-induced asthma and help develop safer, individualized training programs.
Ongoing study — results expected 2025–2026.