At least the researchers admit exercise is important for health — as Freedhoff does, to be fair to him. I just continue to believe that the benefits of exercise should never be downplayed. I've mentioned before that I watched my elderly father fail as he became more and more sedentary. Nobody gets out alive, but keeping moving is essential to slowing the inevitable.
Importantly, this is not to say, that PA per se is not important for overall achievement of health such as the prevention or delay of diabetes and cardiovascular disease, which is undisputed (Glenn et al., 2015; Lin et al., 2015; Long et al., 2015), but that its role in the prevention of population level weight gain may be overstated.
Exercise improves insulin sensitivity. The abstract of the study follows.
A total of 93 participants (87%) completed the study. In the intention-to-treat analysis, the score on the Physical Performance Test, in which higher scores indicate better physical status, increased more in the diet–exercise group than in the diet group or the exercise group (increases from baseline of 21% vs. 12% and 15%, respectively); the scores in all three of those groups increased more than the scores in the control group (in which the score increased by 1%) (P<0.001 for the between-group differences). Moreover, the peak oxygen consumption improved more in the diet–exercise group than in the diet group or the exercise group (increases of 17% vs. 10% and 8%, respectively; P<0.001); the score on the Functional Status Questionnaire, in which higher scores indicate better physical function, increased more in the diet–exercise group than in the diet group (increase of 10% vs. 4%, P<0.001). Body weight decreased by 10% in the diet group and by 9% in the diet–exercise group, but did not decrease in the exercise group or the control group (P<0.001). Lean body mass and bone mineral density at the hip decreased less in the diet–exercise group than in the diet group (reductions of 3% and 1%, respectively, in the diet–exercise group vs. reductions of 5% and 3%, respectively, in the diet group; P<0.05 for both comparisons). Strength, balance, and gait improved consistently in the diet–exercise group (P<0.05 for all comparisons). Adverse events included a small number of exercise-associated musculoskeletal injuries.
Losing weight with exercise is better for your mitochondria than losing it with just calorie restriction. Insulin sensitivity improved with weight loss no matter how it was achieved.
Skeletal muscle extracts glucose from the blood to maintain demand for carbohydrates as an energy source during exercise. Such uptake involves complex molecular signalling processes that are distinct from those activated by insulin. Exercise-stimulated glucose uptake is preserved in insulin-resistant muscle, emphasizing exercise as a therapeutic cornerstone among patients with metabolic diseases such as diabetes mellitus. Exercise increases uptake of glucose by up to 50-fold through the simultaneous stimulation of three key steps: delivery, transport across the muscle membrane and intracellular flux through metabolic processes (glycolysis and glucose oxidation). The available data suggest that no single signal transduction pathway can fully account for the regulation of any of these key steps, owing to redundancy in the signalling pathways that mediate glucose uptake to ensure maintenance of muscle energy supply during physical activity. Here, we review the molecular mechanisms that regulate the movement of glucose from the capillary bed into the muscle cell and discuss what is known about their integrated regulation during exercise. Novel developments within the field of mass spectrometry-based proteomics indicate that the known regulators of glucose uptake are only the tip of the iceberg. Consequently, many exciting discoveries clearly lie ahead.
Children who participated in the NFL’s PLAY 60 fitness program benefited in terms of fitness and obesity measures. Take that Yoni Freedhoff (who has taken to arguing that weight loss is not effective against obesity). Movement is important and should be part of any weight loss program— at least one that isn’t some emergency fast fad loss.
Exercise increases both mitochondria content and mitochondrial electron transport chain and fatty acid oxidation enzyme activities within skeletal muscle, while calorie restriction-induced weight loss did not, despite similar improvements in insulin sensitivity in overweight older adults.