MAXIMAL VOLUNTARY QUADRICEPS STRENGTH PATTERNS IN OLYMPIC OVERTRAINEDATHLETES

Peak torques were studied in 10 elite male overtrained athletes and 10 controls matched for sex, age, sport, and performance level. Isokinet ic concentric (CON) and eccentric (ECC) maximal voluntary contractions (MVC) of quadriceps muscle were assessed at the angular velocities of 60 degrees, 120 degrees, and 180 degrees . s(-1) Sustained isometric MVCs were also measured at knee angles of 10 degrees, 45 degrees, and 80 degrees of flexion. Six seconds after the beginning of each isometr ic MVC, a 40-Hz electrical stimulation was superimposed on the MVC for a further 6 s. The overtrained subjects developed significantly small er CON peak torques at 180 degrees . s(-1) (P < 0.001), although ECC t orques were similar at all three velocities. ECC/CON ratios were highe r in the overtrained subjects at 120 degrees . s(-1) (P < 0.01) and 18 0 degrees . s(-1) (P < 0.001) compared with the controls. Isometric MV Cs at 10 degrees and 45 degrees knee flexion were lower in the overtra ined at P < 0.01 and P < 0.05, respectively. Also in the overtrained s ubjects, at knee angle of 10 degrees, the addition of the electrical s timulation to the isometric MVC produced an increase (P < 0.05) in tor que levels. It is suggested that impaired central drive may account fo r the present findings.