Hk. Vincent et Kr. Vincent, THE EFFECT OF TRAINING STATUS ON THE SERUM CREATINE-KINASE RESPONSE, SORENESS AND MUSCLE FUNCTION FOLLOWING RESISTANCE EXERCISE, International journal of sports medicine, 18(6), 1997, pp. 431-437
Untrained individuals develop muscle soreness and increased serum crea
tine kinase (CK) activity in the blood after strenuous, unaccustomed e
xercise. An unpublished observation in our laboratory revealed that tr
ained weightlifters also experience considerable soreness after unaccu
stomed exercise, but may not show a dramatic CK response. This study e
xamined the CK and soreness responses to strenuous exercise in weightl
ifters (TR, n=10) and untrained subjects (UTR, n=10). Trained subjects
had a minimum of three years weightlifting experience, and regularly
performed squats and leg presses. Untrained subjects had not participa
ted in any regular resistance exercise for the past three years. Follo
wing two acclimation sessions, subjects reported to the lab on seven c
onsecutive days and on the tenth day after knee extensor exercise. Wei
ght training sessions occurred on day 1 for the knee extensors (KE) an
d day 2 for the knee flexors (KF). The weight training consisted of th
ese exercises (sets): squat (5), leg press (3), leg extension and lung
e (3) for the KE, double leg curls (6), single leg curls (3), stiff-le
gged deadlifts (4, TR group only) for the KF at 12 RM for all exercise
s. To document the stress due to exercise, the loss in strength (isome
tric peak torque, IPT) was assessed on a Biodex isokinetic dynamometer
. Maximal voluntary IPT of the KE at 90 degrees and the KF at 80 degre
es decreased 17-30% with no significant differences between groups. Mu
scle soreness during simulated squat leg curl movement was assessed by
a 100 mm visual analog scale (VAS). Average peak KE soreness was 76 m
m for TR and 58 mm for UTR, KF soreness was 60 mm for TR and 47 mm for
UTR post-exercise. Serum CK levels were significantly different betwe
en groups with a peak of 1349 IU for TR and 3272 IU for the UTR (p<0.0
1). Although the TR group experienced greater soreness than the UTR, p
eak serum CK activity was significantly lower, suggesting that trained
individuals can develop severe soreness without the same degree of in
crease in serum CK activity observed in untrained individuals.