Strength training improves muscle aerobic capacity and glucose tolerance in elderly

Abstract

The primary aim of this study was to investigate the effect of short-term resistance training (RET) on mitochondrial protein content and glucose tolerance in elderly. Elderly women and men (age 71 ± 1, mean ± SEM) were assigned to a group performing 8 weeks of resistance training (RET, n = 12) or no training (CON, n = 9). The RET group increased in (i) knee extensor strength (concentric +11 ± 3%, eccentric +8 ± 3% and static +12 ± 3%), (ii) initial (0-30 ms) rate of force development (+52 ± 26%) and (iii) contents of proteins related to signaling of muscle protein synthesis (Akt +69 ± 20 and mammalian target of rapamycin +69 ± 32%). Muscle fiber type composition changed to a more oxidative profile in RET with increased amount of type IIa fibers (+26.9 ± 6.8%) and a trend for decreased amount of type IIx fibers (-16.4 ± 18.2%, P = 0.068). Mitochondrial proteins (OXPHOS complex II, IV, and citrate synthase) increased in RET by +30 ± 11%, +99 ± 31% and +29 ± 8%, respectively. RET resulted in improved oral glucose tolerance measured as reduced area under curve for glucose (-21 ± 26%) and reduced plasma glucose 2 h post-glucose intake (-14 ± 5%). In CON parameters were unchanged or impaired. In conclusion, short-term resistance training in elderly not only improves muscular strength, but results in robust increases in several parameters related to muscle aerobic capacity.

Twelve Weeks of Combined Resistance and Aerobic Exercise Improves Cardiometabolic Biomarkers and Enhances Red Blood Cell Hemorheological Function in Obese Older Men: A Randomized Controlled Trial

“…One meta-analysis reported that a combined exercise program had a moderately positive effect on VO 2peak compared to the control group (3.6 mL·kg −1 ·min −1 ) [58]. In the context of combined training, the inclusion of strength training may provide additional benefits, because previous studies have reported improved cardiorespiratory fitness compatibility after strength training that is potentially mediated by increased mitochondrial enzyme activity and capillary density [59,60]. Furthermore, improvements in lower body muscle strength may also lead to increase the time to "all-out" on a graded exercise test, increasing the observed VO 2peak [61].…”

Exercise, fasting, and mimetics: toward beneficial combinations?

“…Short-term resistance training in elderly subjects, though accompanied by increased Akt/mTOR activity and improved glucose tolerance (167), leads to a shift in muscle phenotype toward a relatively more oxidative metabolism with an increase in type IIa fibers and a tendency toward a decrease in IIx fibers (167). This effect is partially in contrast to what one would predict based on the results obtained in Akt-overexpressing mice (165) and other mouse models in which type II fiber formation is stimulated with the purpose of mimicking resistance exercise (for a review, see ref.…”

The Impact of Sprint Interval Training Frequency on Blood Glucose Control and Physical Function of Older Adults

“…Likewise, twenty weeks of aerobic exercise (four sessions per week at 70% VO 2 max) have also been shown to improve VO 2 peak by 8% and sit to stand performance by 9% [7]. Similar improvements in sit to stand (10%) have also been seen with twenty weeks of resistance training (three sessions per week at 70% 1 repetition maximum, (RM) [7]) whilst 8 weeks of resistance training (three sessions per week at 75%-80% 1 RM) resulted in mitochondrial adaptations with a 20-40% increase in expression of key enzymes related to aerobic metabolism in skeletal muscle [8]. This increase in aerobic metabolism of the skeletal muscle was associated with a lower cardiorespiratory response to submaximal exercise [8].…”

“…Similar improvements in sit to stand (10%) have also been seen with twenty weeks of resistance training (three sessions per week at 70% 1 repetition maximum, (RM) [7]) whilst 8 weeks of resistance training (three sessions per week at 75%-80% 1 RM) resulted in mitochondrial adaptations with a 20-40% increase in expression of key enzymes related to aerobic metabolism in skeletal muscle [8]. This increase in aerobic metabolism of the skeletal muscle was associated with a lower cardiorespiratory response to submaximal exercise [8]. In contrast, the response of blood glucose control has been shown to be blunted in older adults (5% improvement in insulin sensitivity) compared to younger adults (72% improvement in insulin sensitivity) following 16 weeks of aerobic exercise.…”