Effect of aerobic capacity on the T2 increase in exercised skeletal muscle

Robert W. Reid, Jeanne M. Foley, R. C. Jayaraman, Barry M. Prior, Ronald A. Meyer
2001 Journal of applied physiology  
Effect of aerobic capacity on the T 2 increase in exercised skeletal muscle. J Appl Physiol 90: [897][898][899][900][901][902] 2001.-The increase in nuclear magnetic resonance transverse relaxation time (T 2 ) of muscle water measured by magnetic resonance imaging after exercise has been correlated with work rate in human subjects. This study compared the T 2 increase in thigh muscles of trained (cycling V O 2 max ϭ 54.4 Ϯ 2.7 ml O 2 ⅐ kg Ϫ1 ⅐ min Ϫ1 , mean Ϯ SE, n ϭ 8, 4 female) vs. sedentary
more » ... ale) vs. sedentary (31.7 Ϯ 0.9 ml O 2 ⅐ kg Ϫ1 ⅐ min Ϫ1 , n ϭ 8, 4 female) subjects after cycling exercise for 6 min at 50 and 90% of the subjects' individually determined V O 2 max . There was no significant difference between groups in the T 2 increase measured in quadriceps muscles within 3 min after the exercises, despite the fact that the absolute work rates were 60% higher in the trained group (253 Ϯ 15 vs. 159 Ϯ 21 W for the 90% exercise). In both groups, the increase in T 2 of vastus muscles was twofold greater after the 90% exercise than after the 50% exercise. The recovery of T 2 after the 90% exercise was significantly faster in vastus muscles of the trained compared with the sedentary group (mean recovery half-time 11.9 Ϯ 1.2 vs. 23.3 Ϯ 3.7 min). The results show that the increase in muscle T 2 varies with work rate relative to muscle maximum aerobic power, not with absolute work rate.
doi:10.1152/jappl.2001.90.3.897 pmid:11181598 fatcat:3y5mkhrwrrf7jaiaulcwx4ktuu