Fig. 3

Changes in average electromyogram (EMG) values of elbow flexors during the regular weight trials before (Pre) and 2 days after (D2) eccentric exercise (ECC) as well as during the subtracted weight trial in the supplementary experiment (n = 4). In this additional experiment, after ECC, delayed onset muscle soreness (DOMS) appeared in all subjects (from 0.0 ± 0.0 mm at Pre to 31.5 ± 4.4 mm at D2, P = 0.006) and maximal voluntary contraction (MVC) strength significantly (P = 0.007) declined from 27.2 ± 1.0 to 15.6 ± 2.7 kg. For the regular weight trial, subjects’ wrists were fitted with weight belts (average weight = 1.3 kg) equivalent to 5 % of their MVC strength in Pre, and thus, the relative exercise intensity changed to 9 % at D2 due to the ECC-induced reduction in MVC strength. For the subtracted weight trial, weight belts equivalent to 5 % of their MVC strength in D2 were used (average weight = 0.7 kg). Ratings of perceived exertion (RPE) during the regular weight trials was significantly (P < 0.05) increased from Pre (9.9 ± 0.9) to D2 (12.6 ± 1.4); however, RPE during the subtracted weight trial (10.2 ± 1.6) significantly (P < 0.05) declined compared with that during the regular weight trials at D2. Values are expressed as means ± SE. Asterisks represent significant difference (P < 0.05)