Metabolic flexibility in postmenopausal women: Hormone replacement therapy is associated with higher mitochondrial content, respiratory capacity, and lower total fat mass.

Aim: To investigate effects of hormone replacement therapy in postmenopausal women on factors associated with metabolic flexibility related to whole-body parameters including fat oxidation, resting energy expenditure, body composition and plasma concentrations of fatty acids, glucose, insulin, cortisol, and lipids, and for the mitochondrial level, including mitochondrial content, respiratory capacity, efficiency, and hydrogen peroxide emission.

Methods: 22 postmenopausal women were included. 11 were undergoing estradiol and progestin treatment (HT), and 11 were matched non-treated controls (CONT).

Prolonged Endurance Exercise Increases Macrophage Content and Mitochondrial Respiration in Adipose Tissue in Trained Men.

Background: The aim of this study was to investigate the effect of prolonged endurance exercise on adipose tissue inflammation markers and mitochondrial respiration in younger and older men.

Methods: "Young" (aged 30 years, n = 7) and "old" (aged 65 years, n = 7) trained men were exposed to an exercise intervention of 15 consecutive days biking 7 to 9 hours/day at 63% and 65% of maximal heart rate (young and old, respectively), going from Copenhagen, Denmark to Palermo, Italy. Adipose tissue was sampled from both the gluteal and abdominal depot before and after the intervention.

Effects of Aerobic Training and Semaglutide Treatment on Pancreatic β-Cell Secretory Function in Patients With Type 2 Diabetes.

Context: Prior to this study, it is known that type 2 diabetes is linked to obesity and a sedentary lifestyle, leading to inadequate β-cell function and insulin resistance. Limited research has explored the metabolic effects of combining exercise training with antidiabetic medications, particularly focusing on insulin secretion in patients with type 2 diabetes and moderately preserved β-cell function.

Objective: The effect of the interaction of semaglutide and physical training on pancreatic β-cell secretory function is unknown in patients with type 2 diabetes.

Physical activity impacts resting skeletal muscle myosin conformation and lowers its ATP consumption.

It has recently been established that myosin, the molecular motor protein, is able to exist in two conformations in relaxed skeletal muscle. These conformations are known as the super-relaxed (SRX) and disordered-relaxed (DRX) states and are finely balanced to optimize ATP consumption and skeletal muscle metabolism. Indeed, SRX myosins are thought to have a 5- to 10-fold reduction in ATP turnover compared with DRX myosins.

Extreme duration exercise affects old and younger men differently.

Aim & Methods: Extreme endurance exercise provides a valuable research model for understanding the adaptive metabolic response of older and younger individuals to intense physical activity. Here, we compare a wide range of metabolic and physiologic parameters in two cohorts of seven trained men, age 30 ± 5 years or age 65 ± 6 years, before and after the participants travelled ≈3000 km by bicycle over 15 days.

Results: Over the 15-day exercise intervention, participants lost 2-3 kg fat mass with no significant change in body weight.

Reliability and variation in mitochondrial respiration in human adipose tissue.

Adipose tissue mitochondrial function is gaining increasing interest since it is a good marker of overall health. Methodological challenges and variability in assessing mitochondrial respiration in fresh adipose tissue with high-resolution respirometry are unknown and should be explored. Mitochondrial respiratory capacity (MRC) in human adipose tissue declines in a gradual manner when analyses are postponed 3 h and 24 h, with a statistically significant decline 24 h after obtaining the biopsy.

Maximal Fat Oxidation Rate Is Higher in Fit Women and Unfit Women With Obesity, Compared to Normal-weight Unfit Women.

Context: The maximal fat oxidation rate (MFO) is higher in aerobically fit vs unfit young men, but this training-related increase in MFO is attenuated in middle-aged men. Further, it has also been found that unfit men with obesity may have an elevated MFO compared to unfit normal-weight men.

Objective: Based hereupon, we aimed to investigate whether a fitness-related higher MFO were attenuated in middle-aged women compared to young women.

Down stair walking: A simple method to increase muscle mass and performance in 65+ year healthy people.

Exercise is important for prevention of sarcopenia in the elderly population. We tested two training modalities, ascending or descending stair walking, representing concentric (CON) and eccentric (ECC) exercise, respectively. We also tested the effects of additional weight during eccentric exercise (ECC+).

Effects of one-legged high-intensity interval training on insulin-mediated skeletal muscle glucose homeostasis in patients with type 2 diabetes.

Aim: To examine the effect of high-intensity interval training (HIIT) on glucose clearance rates in skeletal muscle and explore the mechanism within the muscle.

Methods: Ten males with type 2 diabetes mellitus (T2DM) and ten matched healthy subjects performed 2 weeks of one-legged HIIT (total of eight sessions, each comprised of 10 × 1 minute ergometer bicycle exercise at >80% of maximal heart rate, interspersed with one min of rest). Insulin sensitivity was assessed by an isoglycaemic, hyperinsulinaemic clamp combined with arteriovenous leg balance technique of the trained (T) and the untrained (UT) leg and muscle biopsies of both legs.

Trajectories of cardio-metabolic health in successful aging.

Maximal oxygen uptake (V̇O ) and muscle mass decrease with age. The loss of cardiorespiratory fitness and muscle strength is accelerated with physical inactivity and has well-documented consequences for morbidity and all-cause mortality. Participation in exercise training programs will improve one or more of the cardio-metabolic risk factors, but the long-term effects of such programs are questionable.