Dohlmann 2014 Abstract MiP2014
|Mitochondrial adaptations to high-intensity training in young and elderly men and women.|
This study investigated how skeletal muscle mitochondria adapt to high intensity interval training (HIT) and whether adaptations differed according to age.
Two groups of healthy sedentary adults completed 18 sessions of low volume HIT (5x1 min @ ~132% of Wmax with 1.5 min rest periods). The groups were matched for BMI and baseline VO2max but differed in age (P<0.001). One group (N=9) aged 36±3 years (BMI 34±2 kg•m-2 and VO2max 2.7±0.2 l•min-1) was considered young (YOUNG), and the other group (N=4) aged 67±2 years (BMI 32±1 kg•m-2 and VO2max 2.1±0.3 l•min-1) was considered old (OLD). Mitochondrial respiration was measured using high-resolution respirometry (Oroboros Oxygraph-2k) in permeabilized muscle fibers from the vastus lateralis, and mitochondrial ADP sensitivity was determined using Michaelis-Menten kinetics.
Following training, YOUNG increased VO2max by 7% (P=0.003), with no change in OLD. Mitochondrial capacity for oxidative phosphorylation (OXPHOS) was increased in both groups (48±2 to 84±4 pmol O2•s-1•mg-1 in YOUNG P<0.001 and 59±9 to 71±11 pmol O2•s-1•mg-1 in OLD P<0.05), and maximal noncoupled respiration was increased in YOUNG (59±4 to 92±5 pmol O2•s-1•mg-1, P<0.05) but not in OLD (71±9 to 80±10 pmol O2•s−1•mg−1). Mitochondrial ADP sensitivity did not change following training in either group (Kmapp [ADP] 0.19±0.10 to 0.16±0.04 in YOUNG, and 0.26±0.18 to 0.15±0.06 in OLD), but maximal ADP stimulated respiration (Jmax) increased in YOUNG (11±1 to 21±2 pmol O2•s-1•mg-1, P<0.05) but not in OLD (13±2 to 17±2 pmol O2•s-1•mg-1).
Our results indicate that the mitochondrial adaptation to HIT in elderly men and women move in the same direction as younger subjects, although only OXPHOS capacity increased significantly in OLD. Due to a low number of subjects in OLD, inclusion of additional subjects is necessary to elucidate exactly how elderly men and women adapt to HIT, compared with younger controls.
Labels: MiParea: Respiration, Exercise physiology;nutrition;life style Pathology: Aging;senescence
Organism: Human Tissue;cell: Skeletal muscle, HeLa, Fibroblast Preparation: Permeabilized cells
Regulation: ADP Coupling state: OXPHOS, ET
HRR: Oxygraph-2k Event: A3, Oral MiP2014:HIT
Xlab, Center Healthy Aging, Dep Biomed Sc, Fac Health Sc, Univ Copenhagen, Denmark. – [email protected]