Affiliations: [a] Department of Motor Sciences, University of Liege,
4000 Liege, Belgium
Note: [] Address for correspondence: Prof. Marc Vanderthommen, University
of Liege, ISEPK (B21), Allée des Sports 4, B-4000 Liege, Belgium. Tel.:
+32 4 366 38 78; Fax: +32 4 366 29 01; E-mail: mvanderthommen@ulg.ac.be
Abstract: Neuromuscular electrical stimulation (ES) and passive recovery (PR)
were compared in ten healthy men after a provocation exercise inducing delayed
onset of muscle soreness (DOMS). The exercise consisted of 3 sets of 30 maximal
eccentric contractions performed by the knee flexor muscles of the dominant leg
on an isokinetic dynamometer at 60°/s angular velocity. There was an
interval of 8 weeks between both bouts and the order of the recovery mode (ES
or PR) was block-randomly assigned. ES recovery consisted of a 25-min
continuous and non-tetanic (5 Hz) stimulation of the hamstring muscles.
Concentric and eccentric hamstrings peak torques were evaluated before and
immediately after the provocation exercise, after the recovery period, as well
as 24 h (d1), 48 h (d2), 72 h (d3) and 168 h (d7) after the bout. Subjective
perception of muscle soreness (VAS, 0–10 a.u.) was evaluated before
exercise and at d1, d2, d3 and d7. To assess the CK activity, five blood
samples were drawn before exercise and at d1, d2, d3 and d7. For both recovery
modes, the greatest reductions in isokinetic muscle performances were measured
on d2 (66.3 ± 24.1% of initial values (ES) vs. 57.4 ± 26.5% (PR)
for the concentric mode and 55.6 ± 16% (ES) vs. 53.1 ± 19.3% (PR)
for the eccentric mode). d2 also corresponded to the highest painful sensations
(5.4 ± 2.14 a.u. (ES) vs. 6.15 ± 2.55 a.u. (PR)). Peak activities
of CK were reached on d3 (47507 ± 19973 IU/l (ES) vs. 75887 ±
41962 IU/l (PR)). Serum CK was lower with ES than PR at d3 (p⩽0.05) but
all other parameters changed in a manner that was not statistically different
between the two recovery protocols (p>0.05). This strong trend could be
explained by an electro-induced hyperperfusion that may efficiently wash out
the muscle from the cellular debris resulting from the initial injury, and
hence diminish the inflammatory response and the delayed amplification of
tissue damages.
