Eccentric Exercise Less Stressful In Trained People
December 18, 2008 | Leave a Comment
Muscle pain is normally connected with eccentric exercise. The muscle contractions cause the fibers to lengthen. For example, walking or running downhill and lowering the weight to the chest during a bench press (negatives). Muscles can gives more force eccentrically (lengthening contractions), than concentrically (shortening contractions), so muscle pain and injury is more frequent in exercises connecting eccentric contractions. Muscles amplify in strength and size mostly by repairing small injuries to the muscles fibers. It also adjusts by adding muscle protein so that similar loads are not as stressful in the future.
Weight-trained people adjust better to intense muscle contraction
Kyle Hackney and co-workers from Wayne State University in Detroit discovered that creatine kinase (a marker of muscle injury and inflammation) and resting energy expenditure were higher in people who did not train than in people who actually trained in the days after a powerful weight-training workout. The program, designed to make muscle soreness, involved eight sets of six repetitions for 8exercises. The training cadence was a second for every concentric contraction and three seconds for every eccentric contraction. The study proved that weight-trained people adjusted to intense muscle contraction and developed protection against possible damaging exercise. On the other hand, muscle damage and the ensuing repair process were greater in people who didn’t train.
(Journal Strength Conditioning Research, 22: 1602-1609, 2008)
