Running preparation for cardiac safety and improved performance
Article information
Marathon participation has increased worldwide in recent years. As more middle-aged and older adults have taken part, the average participant age has risen, and the middle-aged cohort now represents the largest share. Although fatal events are rare among male marathoners, cases often occur late in the race or near the finish line. For individuals with asymptomatic coronary artery disease or other risk factors, pre-race cardiac screening is recommended.
Among middle-aged male marathon participants, the leading causes of sudden death are cardiac diseases, particularly coronary artery disease and acute myocardial infarction. Vigorous exercise such as marathon running imposes acute cardiovascular stress, which can precipitate sudden cardiac death in those with latent disease. Prolonged high-intensity efforts may also be associated with elevated blood pressure, transient ventricular remodeling, and increased vascular stiffness. Less commonly, congenital heart disease, conduction abnormalities, dehydration, electrolyte imbalance, and excessive intake of caffeine or stimulants can contribute.
Untrained runners carry a markedly higher risk compared with trained runners. Repeated training confers cardioprotection and substantially reduces the likelihood of adverse events. Most documented sudden deaths occur in runners with underlying cardiovascular disease or baseline risks.
Before entering a marathon, individuals should complete a structured, progressive training program of at least 16 weeks. In untrained middle-aged men, completing a marathon after a 16-week program has been associated with transient cardiac changes, with all measured parameters returning to baseline within 4 weeks. Longer-term training (e.g., 8 months) can improve blood pressure, reduce body fat, and favorably modify cardiovascular risk factors. A practical target is four to five sessions per week of approximately one hour each, with gradual increases in distance and intensity.
Hydration is essential for performance, health maintenance, and safe completion. Key considerations include appropriate fluid intake, dehydration thresholds, and the risk of overhydration that can lead to exercise-associated hyponatremia. A body-mass loss of about 2% from dehydration is commonly cited as a threshold at which performance and cardiovascular strain may worsen; however, training adaptations and individual variability are substantial, and some well-trained athletes complete races with greater fluid deficits. Elite marathoners typically ingest roughly 200–800 mL of fluid per hour, whereas untrained runners tend to drink more frequently and in larger volumes.
Because dehydration depends on temperature, humidity, pace, and sweat rate, timing and degree vary widely. Exercise-associated muscle cramps appear more closely linked to muscle damage than to isolated fluid or electrolyte loss. Water, sports drinks, and electrolyte supplements show minimal differences for routine dehydration recovery in most situations. Practical guidance is to avoid exceeding about 2% body-mass loss, drink approximately 400–800 mL per hour guided by thirst, and avoid a total intake above roughly 3 L during the event to reduce the risk of hyponatremia. Individuals with known genetic or clinical risk factors for heart disease should undergo cardiac screening before participating.
Notes
CONFLICT OF INTEREST
No potential conflict of interest relevant to this article was reported.