Background: Regular physical activity is highly recommended in preventive, curative, and rehabilitative programs in order to promote health, especially cardiovascular health. However, physical activity can also cause sudden death. In athletes, sudden death may occur during sport competitions, with myocardial infarction as the most common etiology. It is suspected that continuous training withou...

Extensive research has been performed examining eccentric contraction and related muscle injury. Only a few studies have examined muscle failure due to an imposed tissue strain. Those that have examined failure tend to investigate active muscle failure and define failure as complete tearing of the muscle. However, muscle damage is known to occur well before a tear is apparent, and failure may b...

The effect of ethanol ingestion on exercise-induced muscle damage was examined. It has been reported that a reduced leakage of muscle proteins was found when alcohol was ingested prior to exercise. The results of that study were confounded by repeating the same exercise using the same muscle groups; the alcohol treatment was always given on the second exercise bout so that the reduced protein l...

The skeletal muscle tissue has a remarkable capacity to regenerate upon injury. Recent studies have suggested that this regenerative process is improved when AMPK is activated. In the muscle of young and old mice a low calorie diet, which activates AMPK, markedly enhances muscle regeneration. Remarkably, intraperitoneal injection of AICAR, an AMPK agonist, improves the structural integrity of m...

Novel eccentric (lengthening contraction) exercise typically results in muscle damage, which manifests as prolonged muscle dysfunction, delayed onset muscle soreness, and leakage of muscle proteins into circulation. There is a large degree of variability in the damage response of individuals to eccentric exercise, with higher responders at risk for potentially fatal rhabdomyolysis. We hypothesi...

It is unknown whether muscle damage at the level of the sarcomere can be induced without lengthening contractions. To investigate this, we designed a study where seven young, healthy men underwent 30 min of repeated electrical stimulated contraction of m. gastrocnemius medialis, with the ankle and leg locked in a fixed position. Two muscle biopsies were collected 48 h later: one from the stimul...

The possible pathways of oxidative stress in anaerobic exercise includes transient and acute muscular deoxygenation, which resembles the ischemiareperfusion, xanthine oxidase activation, catecholamine autoxidation, and NADPH oxidase activation, prostanoid metabolism, phagocyte respiratory burst activity, disruption of iron containing proteins, and altered calcium homeostasis. 5 Mechanical stres...

Skeletal muscle regeneration is severely compromised in the case of extended damage. The current challenge is to find factors capable of limiting muscle degeneration and/or potentiating the inherent regenerative program mediated by a specific type of myoblastic cells, the satellite cells. Recent studies from our groups and others have shown that the bioactive lipid, sphingosine 1-phosphate (S1P...