Irisin Response To Down-hill Running Exercise In Humans

Abstract

To determine the effects of exercise-induced muscle damage, we examined irisin responses during level running (LR), with less muscle damage, and downhill running (DHR), with greater muscle damage under equivalent exercise duration and oxygen consumption (V 3 O2) conditions.[Methods] Fifteen healthy men (age: 21.6 ± 2.0 y, height: 170 ± 1.3 cm, weight: 64.8 ± 2.7 kg) were randomly assigned to either the LR group (n = 8) or the DHR group (n = 7). Subjects in the LR group performed treadmill running at 70% of maximum oxygen uptake (V 3 O2max) for 30 min on a 0% gradient. In contrast, subjects in the DHR group performed the same exercise on a -10% gradient. Blood samples were collected before exercise, immediately after exercise, and 1, 3, and 24 h after exercise.[Results] No significant interaction (group × time) or main effect of group or time was observed for changes in plasma irisin concentrations over time (P > 0.05). However, the area under the curve of plasma irisin concentrations during a 3-h post-exercise period was significantly greater in the DHR (239,197 ± 8,166 ng/ mL) group than in the LR (92,293 ± 8,755 ng/ml) group (P < 0.05). The blood lactate, serum cortisol, myoglobin, and plasma interleukin-6 concentrations were significantly higher in the DHR group than in the LR group after exercise (P < 0.05 for all variables).[Conclusion] DHR associated with marked muscle damage promoted a greater increase in exercise-induced irisin did LR after the same duration under identical VO2 conditions.

The influence of concurrent training intensity on serum irisin and abdominal fat in postmenopausal women

“…Based on existing studies, exercise type (endurance/ resistance), exercise time (acute/chronic), exercise intensity, and personal training prior to participation in studies count as factors affecting the circulating irisin level. Indeed, different studies have reported physical exercise influences are significant in irisin circulation levels [8][9][10], while other studies show that exercise, acute and/or chronic, has no substantial effect on blood irisin level [11][12][13]. Therefore, the role of exercise on irisin activity has been a controversial subject [14][15][16][17].…”