Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .
RESPONSES OF ELBOW FLEXORS TO TWO STRENUOUS ECCENTRIC EXERCISE BOUTS SEPARATED BY THREE DAYS
This study investigated whether the second eccentric exercise performed 3 days after the initial bout would exacerbate muscle damage and retard the recovery .  Fifty-one athletes performed  30 eccentric actions of the elbow flexors  using a dumbbell weighted 100 % of the maximal isometric force ( MIF ) at the elbow joint angle of 908 ( ECC1 ) . Three days after ECC1 , all subjects except those in the control group ( n = 12 ) performed the second bout ( ECC2 ) with the same ( 100 % ) intensity ( n = 12 ) , 90 % ( n = 13 ) , or 80 % ( n = 14 ) of the ECC1 . Some subjects , especially in the 100 % group , required spotting for ECC2 but made maximal effort to complete the exercise . MIF , range of motion , upper-arm circumference , muscle soreness , muscle proteins in the blood , and ultrasound images were used to assess muscle damage . Changes in these measures for 9 days following ECC1 were compared among groups by 2-way analysis of variance ( ANOVA ) with repeated measures . All criterion measures changed significantly after ECC1 ; however , no significant differences between the groups were evident for any of the changes in the measures . These results suggest that it is possible for athletes to complete the second bout if the intensity is reduced 10–20 % from the initial bout . No significant differences between the control group and other groups indicate that the second eccentric exercise performed 3 days after the initial bout does not exacerbate muscle damage and retard the recovery regardless of the intensity of the second bout . It is concluded that the elbow flexors can perform high-intensity eccentric exercise in the early stage of recovery from the initial bout and are not damaged further by performing a subsequent bout 3 days after the first
Conclusion Overall , our findings do not support the presence of a secondary loss of strength following an acute muscle injury , and strongly suggest that strength , on average , recovers steadily over the first 3 days post-injury
Background An immediate loss of strength follows virtually all types of muscle injury but there is debate whether the initial strength loss is maximal or if a secondary loss of strength occurs during the first 3 days post-injury .
Objective The objective of this analysis was to conduct a systematic review and meta- analysis of the research literature to determine if a secondary loss of strength occurs after an injurious initiating event .