Sleep Management Strategy and Performance in an Extreme Mountain Ultra-marathon.

We intended to assess the relationship between sleep strategies and performance during the North-Face Ultra-Trail du Mont-Blanc 2013, to test the hypothesis that sleep management can influence athletic performance. Almost all runners specifically adopted sleep management strategies before the race. Among the finishers 72% didn't sleep at all during the race and 28% took a least one break for sleep. Non-sleepers completed the race faster than the sleepers (P = 0.0008). Race time was positively correlated with drowsiness (P < 0.0001) and negatively correlated with the number participations in this race (P = 0.0039). Runners who adopted a sleep management strategy based on increased sleep time before the race completed the race faster (P = 0.0258). Most finishers seemed to be aware of the importance of developing sleep management strategies and increasing sleep time some nights before the race appeared to be the most relevant strategy to improve performance.

Supine changes in lung function correlate with chronic respiratory failure in myotonic dystrophy patients.

Quality of life and prognosis of patients with myotonic dystrophy type 1 (MD1) often depend on the degree of lung function impairment. This study was designed to assess the respective prevalence of ventilatory restriction, hypoxaemia and hypercapnia in MD1 patients and to determine whether postural changes in lung function could contribute to the early diagnosis of poor respiratory outcome. Fifty-eight patients (42.6±12.9 years) with MD1 were prospectively evaluated from April 2008 to June 2010 to determine their supine and upright lung function and arterial blood gases. The prevalence of ventilatory restriction was 36% and increased with the severity of muscular disability (from 7.7% to 70.6%). The prevalence of hypoxaemia and hypercapnia was 37.9% and 25.9%, respectively. Multiple regression analysis showed that the supine fall in FEV1 was the only variable associated with ventilatory restriction, hypoxaemia and hypercapnia. Our data indicate that supine evaluation of lung function could be helpful to predict poor respiratory outcome, which is closely correlated with hypoxaemia and/or hypercapnia.

Left ventricle fibrosis associated with nonsustained ventricular tachycardia in an elite athlete: is exercise responsible? A case report.

OBJECTIVE: To emphasize the potentially harmful effects of high-intensity exercise on cardiac health and the fine line between physiologic and pathologic adaptation to chronic exercise in the elite athlete. This case also highlights the crucial need for regular evaluation of symptoms that suggest cardiac abnormality in athletes. BACKGROUND: Sudden cardiac death (SCD) of young athletes is always a tragedy because they epitomize health. However, chronic, high-intensity exercise sometimes has harmful effects on cardiac health, and pathologic changes, such as myocardial fibrosis, have been observed in endurance athletes. In this case, a highly trained 30-year-old cyclist reported brief palpitations followed by presyncope feeling while exercising. Immediate investigations revealed nonsustained ventricular tachycardia originating from the left ventricle on a stress test associated with myocardial fibrosis of the left ventricle as shown with magnetic resonance imaging. Despite complete cessation of exercise, life-threatening arrhythmia and fibrosis persisted, leading to complete restriction from competition. Differential Diagnosis: Hypertrophic cardiomyopathy, arrhythmogenic right ventricular cardiomyopathy, myocarditis, postmyocarditis, use of drugs and toxic agents, doping, and systemic disease. TREATMENT: The arrhythmia could not be treated with catheter ablation procedure or drug suppression. Therefore, the athlete was instructed to withdraw completely from sport participation and to have a medical follow-up twice each year. UNIQUENESS: To our knowledge, no other report of left ventricle exercise-induced fibrosis associated with life-threatening arrhythmia in a living young elite athlete exists. Only postmortem evidence supports such myocardial pathologic adaptation to exercise. CONCLUSIONS: To prevent SCD in young athletes, careful attention must be paid to exercise-related symptoms that suggest a cardiac abnormality because they more often are linked to life-threatening cardiovascular disease.