Effect of aerobic capacity on the T2 increase in exercised skeletal muscle
Journal of applied physiology
Effect of aerobic capacity on the T 2 increase in exercised skeletal muscle. J Appl Physiol 90:  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
... 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.