title: Leg vascular and skeletal muscle mitochondrial adaptations to aerobic high-intensity exercise training are enhanced in the early postmenopausal phase.
abstract: Exercise training effectively improves vascular and skeletal muscle function; however, these effects of training may be blunted in postmenopausal women as a result of the loss of oestrogens. Accordingly, the capacity to deliver oxygen to the active muscles may also be impaired in postmenopausal women. In both premenopausal and recent postmenopausal women, exercise training was shown to improve leg vascular and skeletal muscle mitochondrial function. Interestingly, these effects were more pronounced in postmenopausal women. Skeletal muscle oxygen supply and utilization were similar in the two groups of women. These findings suggest that the early postmenopausal phase is associated with an enhanced capacity of the leg vasculature and skeletal muscle mitochondria to adapt to exercise training and that the ability to deliver oxygen to match the demand of the active muscles is preserved in the early phase following the menopausal transition.
  
  
  
  Exercise training leads to favourable adaptations within skeletal muscle; however, this effect of exercise training may be blunted in postmenopausal women as a result of the loss of oestrogens. Furthermore, postmenopausal women may have an impaired vascular response to acute exercise. We examined the haemodynamic response to acute exercise in matched pre- and postmenopausal women before and after 12 weeks of aerobic high intensity exercise training. Twenty premenopausal and 16 early postmenopausal (mean ± SEM: 3.1 ± 0.5 years after final menstrual period) women only separated by 4 years of age (mean ± SEM: 50 ± 0 years vs. 54 ± 1 years) were included. Before training, leg blood flow, O2delivery, O2uptake and lactate release during knee-extensor exercise were similar in pre- and postmenopausal women. Exercise training reduced (P < 0.05) leg blood flow, O2delivery, O2uptake, lactate release, blood pressure and heart rate during the same absolute workloads in postmenopausal women. These effects were not detected in premenopausal women. Quadriceps muscle protein contents of mitochondrial complex II, III and IV; endothelial nitric oxide synthase (eNOS); cyclooxygenase (COX)-1; COX-2; and oestrogen-related receptor α (ERRα) were increased (P < 0.05) with training in postmenopausal women, whereas only the levels of mitochondrial complex V, eNOS and COX-2 were increased (P < 0.05) in premenopausal women. These findings demonstrate that vascular and skeletal muscle mitochondrial adaptations to aerobic high intensity exercise training are more pronounced in recent post- compared to premenopausal women, possibly as an effect of enhanced ERRα signalling. Also, the hyperaemic response to acute exercise appears to be preserved in the early postmenopausal phase.
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Michael
authors.identifier: 0000-0002-3937-4697
authors.initials: M
authors.lastname: Nyberg
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jon
authors.identifier: 0000-0003-4353-0362
authors.initials: J
authors.lastname: Egelund
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Camilla M
authors.initials: CM
authors.lastname: Mandrup
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.|Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Caroline B
authors.initials: CB
authors.lastname: Andersen
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Karen M B E
authors.initials: KMBE
authors.lastname: Hansen
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ida-Marie F
authors.initials: IF
authors.lastname: Hergel
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Nicholai
authors.identifier: 0000-0003-0175-8908
authors.initials: N
authors.lastname: Valbak-Andersen
authors.affiliation: Department of Clinical Biochemistry, Rigshospitalet, Copenhagen, Denmark.|Department of Clinical Medicine, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ruth
authors.initials: R
authors.lastname: Frikke-Schmidt
authors.affiliation: Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Bente
authors.identifier: 0000-0003-3117-0451
authors.initials: B
authors.lastname: Stallknecht
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Jens
authors.identifier: 0000-0003-1305-9274
authors.initials: J
authors.lastname: Bangsbo
authors.affiliation: Department of Nutrition, Exercise and Sports, University of Copenhagen, Copenhagen, Denmark.
authors.forename: Ylva
authors.identifier: 0000-0002-2435-9558
authors.initials: Y
authors.lastname: Hellsten
mesh_terms: D000222:Adaptation, Physiological; D005260:Female; D000072696:High-Intensity Interval Training; D006801:Humans; D007866:Leg / Q000502:physiology; D008875:Middle Aged; D008931:Mitochondria, Muscle / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000098:blood supply / Q000502:physiology*; D010101:Oxygen Consumption; D017698:Postmenopause / Q000502:physiology*; D012039:Regional Blood Flow
keywords: blood flow; menopause; oestrogen