E. Prou et al., EFFECTS OF STRENUOUS EXERCISE ON SERUM MYOSIN HEAVY-CHAIN FRAGMENTS IN MALE TRIATHLETES, International journal of sports medicine, 17(4), 1996, pp. 263-267
During the Nice Triathlon (June 26, 1994), the serum levels of type I
myosin heavy chain (MHC) fragments and creatine kinase (CK and CK-MB)
activities were assessed in 12 athletes in order to evaluate the exerc
ise-induced muscle damage. Blood samples (BS) were taken 2 days before
the event (baseline), on arrival, 6 and 24 h later, and 2 and 4 days
later. The mean results (and SD) were respectively: MHC (mu U . l(-1))
: 142 (69), 156 (116), 242 (144), 1183 (574), 2603 (1405), 1002 (523);
CK (U . l(-1)): 109 (27), 626 (267), 1188 (562), 1159 (442), 633 (385
), 224 (119). The CK peak occurred at BS-6h for 8 subjects, and at BS-
24h for the other ones. The MHC peak occurred at BS-48h in all the sub
jects. The CK-MB/CK ratios exhibited a profile similar to those descri
bed previously, Serum MHC peak va rues were correlated with CK ones (r
= 0.67; p<0.05). After a four-day recovery period, as the CK values h
ad decreased, the MHC levels were still elevated. The main result of t
he study is the MHC peak occurrence at BS-48h in all the subjects.