The Effects of Obesity and Resistance Exercise Order on Fatigue

The aim of this study was to investigate the effect of acute resistance exercise with different movement orders on fatigue parameters (serotonin and RPE test) in non-athlete men (normal weight and obese). 26 male university students were purposively selected and assigned to obese (n-11) and normal weight groups (n=15). In the first session, half of the subjects (both obese and normal) randomly performed resistance protocol A (resistance exercise from large to small muscles) and the rest of the subjects performed resistance protocol B (resistance exercise from small to large muscles). The second session was three days later with reverse protocols. In each session, subjects performed 3 sets to exhaustion for 9 movements with 10RM. In each session, blood samples were collected before, immediately after and 30 min. after the exercise. Results using ANOVA with repeated measures showed that serum serotonin concentration significantly increased in both obese and normal groups (P<0.05) immediately after the protocol B (not protocol A) and returned to the baseline after 30 min of recovery. However, resistance exercise order had no effect on serum cortisol changes. In addition, both groups had higher RPE during resistance protocol B (P>0.05) although the difference was not significant compared with the protocol A. Overall, the findings of this study showed that when the resistance movements are preceded by small muscles, greater fatigue will happen, but obesity is ineffective in this regard, although obesity was associated with milder cortisol changes.