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Indexed/Abstracted in: Chemical Abstracts, CINAHL, Current Contents/Clinical Medicine, EMBASE, PubMed/MEDLINE, Science Citation Index Expanded (SciSearch), Scopus
Impact Factor 1,111
Online ISSN 1827-1928
EXERCISE PHYSIOLOGY AND BIOMECHANICS
Valli P. 1, Boldrini L. 1, Bianchedi D. 1, Brizzi G. 2, Miserocchi G. 3
1 School of Sport Medicine University of Milan, Milan, Italy
2 Sintesi, Linea di Fiorano, Bergamo, Italy
3 University of Milano-Bicocca, Milano, Italy
Background. 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.
Methods. 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). Variables measured: 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. Participants: 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).
Results. 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.
Conclusions. Low intensity ES in sedentary and poorly performing people increases significantly FMAX during MVC possibly via facilitatory neurogenic mechanism.