Electrical Stimulation of Quadriceps Femoris in an Elite Weight Lifter: A Single Subject Experiment
14 March 2008 (online)
The response to treatment of high intensity neuromuscular electrical stimulation (NMES) to both quadriceps femoris muscles as an adjunct to ongoing weight training was evaluated using a single subject experimental design. For an elite weight lifter weekly maximal measurements of snatch (S), clean and jerk (CJ), and front squat (SQ) were obtained over 4 months during which the subject weight trained daily for 3 h. The 1st month, baseline data were collected. After baseline measurements, a 1-month period of high-intensity NMES was added to the subject's weight training. NMES was then withdrawn for 1 month and administered once more for 2 weeks. Three quadriceps femoris muscle biopsies were taken, two during the initial baseline period and one just before the end of the first stimulation period. The results showed a significant and clear relationship between performance gains and NMES administration and withdrawal. Steep gains for S, CJ, and SQ were seen after 2 weeks of stimulation, with front squat showing a 20-kg increase within the 1st week of both stimulation periods. Muscle biopsy showed an increased type I fiber area, decreased type Ha and lib fiber area, and an increase of type II fibers after NMES. The results of this study support the use of high-dose NMES as an adjunct to weight training in elite lifters.
Electrical stimulation - muscle fibers - weight lifter - strength