Effect of low intensity electrical stimulation on quadriceps muscle voluntary maximal strength
Valli, P.; Boldrini, L.; Bianchedi, D.; Brizzi, G.; Miserocchi, G.
Journal of Sports Medicine and Physical Fitness 42(4): 425-430
2002
ISSN/ISBN: 0022-4707 PMID: 12391436 Document Number: 546810
Evaluate the effect of low intensity electrical stimulation (ES) training on strength. We purposefully used a low ES stimulation intensity to have it well accepted by middle aged and low performing people. Relate strength to metabolic parameters. Experimental design. Protocol 1: effects of 11 day low intensity ES training on quadriceps muscle maximal voluntary contraction (MVC). Protocol 2: effects of 3 day training at low intensity ES + voluntary contraction at 60% of MVC (co-contraction). maximal voluntary strength (FMAX), strength during ES (FES), strength developed during co-contraction (FES-C), oxygen consumption, heart rate. Experimental design included a basal session, a training program and controls of measured variables during and at the end of the training program. protocol 1: experiments were done on 13 healthy and sedentary subjects (6 males and 7 women, mean age 50.6 years). Protocol 2: experiments done on 6 healthy sedentary men (mean age 31.5 years). Protocol 1: FMAX increased significantly (p<0.05) to 14 and 19% at day 6 and 11, respectively. During ES, oxygen consumption increased by 20%, but no change in heart rate was observed. Protocol 2: FMAX significantly increased (about 5%) in subjects who trained with co-contraction; conversely, FMAX did not significantly increase in a control group matched for age who trained only with voluntary contractions. Low intensity ES in sedentary and poorly performing people increases significantly FMAX during MVC possibly via facilitatory neurogenic mechanism.