Research
Research projects and results
Asthma in Cross-Country 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 (BMJ Open S&EM 2022) · Review (Finnish Medical Journal 2024)
Current research
A follow-up study was conducted in 2022 to investigate asthma incidence and related factors. Manuscript in preparation.
Athlete's Cough
What we already know
- 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)
Current research
This study investigates cough frequency and impact during and after endurance exercise in winter conditions, particularly in cross-country skiers. We use the CE-certified SIVA MVP 1.0 cough monitor for objective cough monitoring. The aim is to describe exercise-related cough and potentially develop new treatment approaches for athletes with exercise-provoked respiratory symptoms.
Why Does Asthma Develop in Athletes?
The athlete's airways warm and humidify inhaled air under demanding conditions for extended periods. High-volume endurance training is associated with increased asthma prevalence. We are developing a measurement method to assess exhaled air humidity and temperature and model the athlete's airways during exercise.
The research comprises three integrated subprojects:
- EXHALE — We develop a measurement device for exhaled air temperature and humidity during endurance exercise and study the airway conditioning burden under different environmental conditions.
- AIRWAY-FIN — We establish a standardised clinical diagnostic and monitoring pathway for identifying and managing respiratory disease in endurance athletes.
- PERFORM — We determine through a randomised trial whether diagnosing and treating previously unrecognised asthma improves endurance performance.
Ongoing research.
Research Timeline
351 competitive cross-country skiers and 338 controls surveyed on asthma and respiratory symptoms.
Systematic review and meta-analysis on asthma in skiers published in Sports Medicine.
Four peer-reviewed articles on asthma prevalence, training volume, cough and respiratory infections.
Skiers and controls re-surveyed to study asthma incidence and related factors.
Rikhard Mäki-Heikkilä's thesis: Asthma and Respiratory Symptoms in Finnish Competitive Cross-Country Skiers.
Three subprojects: EXHALE (airway conditioning), AIRWAY-FIN (diagnostic pathway), PERFORM (treatment response).