Affiliations: [a] Federal University of Rio Grande do Sul (UFRGS),
Physical Education School, Exercise Research Laboratory, Porto Alegre, RS,
Brazil
Note: [] Address for correspondence: Bruno Manfredini Baroni,
Laboratório de Pesquisa do Exercício; Rua Felizardo, 750, Bairro
Jardim Botânico; Porto Alegre – RS, Brasil 90690-200. Tel.: +55 51 330
85859; E-mail: bmbaroni@yahoo.com.br
Abstract: This study investigated knee extensor muscle strength, work and
fatigue level under maximal isokinetic concentric and eccentric exercise.
Seventeen male athletes were randomized into two groups and performed 10 sets
of 10 maximal isokinetic concentric (N =8) or eccentric
(N =9) contractions. Knee extensor peak torque and mean
torque values per set were 54–121% and 53–133% higher in eccentric
compared to concentric exercise, respectively, whereas the percent fall of
performance in these variables was more accentuated in concentric exercise.
Total work was significantly higher in eccentric exercise (19475 J) than
concentric exercise (15758 J), while fatigue index was greater in concentric
(36%) than eccentric (18%) exercise. In conclusion, maximal isokinetic
eccentric exercise promotes larger overload to knee extensor muscles than its
concentric counterpart due to higher torque produced by the muscle group and
also thanks to minor muscle fatigue effects.
