Microvascular adaptations to resistance training are independent of load in resistance-trained young men Academic Article uri icon

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abstract

  • Resistance training promotes microvasculature expansion; however, it remains unknown how different resistance training programs contribute to angiogenesis. Thus, we recruited experienced resistance-trained participants and determined the effect of 12 wk of either high-repetition/low-load or low-repetition/high-load resistance training performed to volitional fatigue on muscle microvasculature. Twenty men performed either a high-repetition [20-25 repetitions, 30-50% of 1-repetition maximum (1RM); n = 10] or a low-repetition (8-12 repetitions, 75-90% of 1RM; n = 10) resistance training program. Muscle biopsies were taken before and after resistance training, and immunohistochemistry was used to assess fiber type (I and II)-specific microvascular variables. High-repetition/low-load and low-repetition/high-load groups were not different in any variable before resistance training. Both protocols resulted in an increase in capillarization. Specifically, after resistance training, the capillary-to-fiber ratio, capillary contacts, and capillary-to-fiber perimeter exchange index were elevated, and sharing factor was reduced. These data demonstrate that resistance training performed to volitional failure, using either high repetition/low load or low repetition/high load, induced similar microvascular adaptations in recreationally resistance-trained young men.

authors

  • Holloway, Tanya M
  • Morton, Robert W
  • Oikawa, Sara Y
  • McKellar, Sean
  • Baker, Steven K
  • Phillips, Stuart

publication date

  • August 2018