TY - JOUR

T1 - How long does the protective effect on eccentric exercise-induced muscle damage last?

AU - Nosaka, K.

AU - Sakamoto, K.

AU - Newton, M.

AU - Sacco, P.

PY - 2001/1/1

Y1 - 2001/1/1

N2 - Purpose: One bout of eccentric exercise produces an adaptation that reduces muscle damage in subsequent bouts. Because it is not known how long this adaptation lasts, the present study investigated the maximal length of the attenuated changes in muscle damage indicators after high-force eccentric exercise. Methods: Male students (N = 35) were placed into three groups and performed two bouts of eccentric exercise of the nondominant elbow flexors separated by either 6 (N = 14), 9 (N = 11), or 12 (N = 10) months. Maximal isometric force (MIF), range of motion (ROM), upper arm circumference (CIR), muscle soreness (SOR), and plasma creatine kinase activity (CK) were measured before and tot 5 d after exercise. Magnetic resonance (MR) images of the transverse and longitudinal scans of the upper arm were taken 4 d after exercise. Changes in the criterion measures were compared between the first and second bouts and between groups by a two-way repeated measures ANOVA. Results: A faster recovery in MIF was evident after a second bout performed at 6 or 9 months, and reduced SOR as well as smaller increases in CIR, CK, and T2 relaxation time of MR images also occurred after the second exercise bout at 6 months compared with initial responses. No significant differences between the bouts were found for ROM, and the12-month group did not show any repeated bout effect. Conclusion: These results show that the repeated bout effect for most of the criterion measures lasts at least 6 months but is lost between 9 and 12 months.

AB - Purpose: One bout of eccentric exercise produces an adaptation that reduces muscle damage in subsequent bouts. Because it is not known how long this adaptation lasts, the present study investigated the maximal length of the attenuated changes in muscle damage indicators after high-force eccentric exercise. Methods: Male students (N = 35) were placed into three groups and performed two bouts of eccentric exercise of the nondominant elbow flexors separated by either 6 (N = 14), 9 (N = 11), or 12 (N = 10) months. Maximal isometric force (MIF), range of motion (ROM), upper arm circumference (CIR), muscle soreness (SOR), and plasma creatine kinase activity (CK) were measured before and tot 5 d after exercise. Magnetic resonance (MR) images of the transverse and longitudinal scans of the upper arm were taken 4 d after exercise. Changes in the criterion measures were compared between the first and second bouts and between groups by a two-way repeated measures ANOVA. Results: A faster recovery in MIF was evident after a second bout performed at 6 or 9 months, and reduced SOR as well as smaller increases in CIR, CK, and T2 relaxation time of MR images also occurred after the second exercise bout at 6 months compared with initial responses. No significant differences between the bouts were found for ROM, and the12-month group did not show any repeated bout effect. Conclusion: These results show that the repeated bout effect for most of the criterion measures lasts at least 6 months but is lost between 9 and 12 months.

KW - Maximal isometric force

KW - Muscle soreness

KW - Plasma CK activity

KW - Swelling

KW - T2 relaxation time

UR - http://www.scopus.com/inward/record.url?scp=0034847053&partnerID=8YFLogxK

U2 - 10.1097/00005768-200109000-00011

DO - 10.1097/00005768-200109000-00011

M3 - Journal article

C2 - 11528337

AN - SCOPUS:0034847053

VL - 33

SP - 1490

EP - 1495

JO - Medicine and Science in Sports and Exercise

JF - Medicine and Science in Sports and Exercise

SN - 0195-9131

IS - 9

ER -