Repetition speed in resistance training for elderly
The age-related loss of muscle mass (sarcopenia) has shown to be a causative factor for functional decline in elders. Progressive resistance training is a proven and effective intervention to increase muscle mass and power in this population. However, as much of the conventional wisdom regarding resistance training is based upon data from younger individuals, there remains significant debate within the literature about the underlying science and optimization of this intervention in the elderly.
The loss of muscle mass and power has been strongly linked with satellite cellular senescence, along with an increased expression of type one 1 muscle fibres (slow twitch) and decreased expression of type 2 muscle fibres (fast twitch). Ultimately, this age-related decrease in type 2 muscle fibres is genetically mediated through myosin heavy chain transcription (MyHC). While the concept of high speed repetition resistance training has shown to be effective in increasing muscle power, optimal parameters of resistance training for altering MyHC, specifically repetition timing, have not yet been described.
A recent study assessed the effect of high velocity versus low velocity resistance training on functional strength outcomes, as well as MyHC transcript expression in high functioning elders. The authors utilised a 6-week training protocol of either fast or slow repetition exercises and conducted muscle biopsies at baseline and post intervention to assess MyCH expression. Post intervention muscle testing showed both groups to have increased muscle power, however, a novel and significant upregulation in MyCH transcription expression for type 2 muscle fibres was seen only in the high velocity training group, indicating that these changes are velocity dependent.
The results of this small study are the first data to show that high velocity resistance training does not only lead to improved muscle power, but that it also can affect in vivo genetic expression of muscle fibre type in elderly. Accordingly, where safe to do so, high velocity should be considered as an intervention in elders who are at risk for, or suffering from sarcopenia and age related functional decline.
> From: Englund et al., Exp Geront 91 (2017) 51-56. All rights reserved to Elsevier Inc. Click here for the online summary.