Exercise may have different effects in the morning and evening
June 13, 2019
Science Daily/University of Copenhagen The Faculty of Health and Medical Sciences
Researchers from the University of Copenhagen have learned that the effect of exercise may differ depending on the time of day it is performed. In mice they demonstrate that exercise in the morning results in an increased metabolic response in skeletal muscle, while exercise later in the day increases energy expenditure for an extended period of time.
We probably all know how important a healthy circadian rhythm is. Too little sleep can have severe health consequences. But researchers are still making new discoveries confirming that the body's circadian clock affects our health.
Now, researchers from University of Copenhagen -- in collaboration with researchers from University of California, Irvine -- have learned that the effect of exercise may differ depending on the time of day it is performed. Studies in mice reveal that the effect of exercise performed in the beginning of the mouse' dark/active phase, corresponding to our morning, differs from the effect of exercise performed in the beginning of the light/resting phase, corresponding to our evening.
'There appears to be rather significant differences between the effect of exercise performed in the morning and evening, and these differences are probably controlled by the body's circadian clock. Morning exercise initiates gene programs in the muscle cells, making them more effective and better capable of metabolising sugar and fat. Evening exercise, on the other hand, increases whole body energy expenditure for an extended period of time', says one of the researchers behind the study, Associate Professor Jonas Thue Treebak from the Novo Nordisk Foundation Center for Basic Metabolic Research.
Morning Exercise Is Not Necessarily Better than Evening Exercise
The researchers have measured a number of effects in the muscle cells, including the transcriptional response and effects on the metabolites. The results show that responses are far stronger in both areas following exercise in the morning and that this is likely to be controlled by a central mechanism involving the protein HIF1-alfa, which directly regulates the body's circadian clock.
Morning exercise appears to increase the ability of muscle cells to metabolise sugar and fat, and this type of effect interests the researchers in relation to people with severe overweight and type 2 diabetes.
On the other hand, the results also show that exercise in the evening increases energy expenditure in the hours after exercise. Therefore, the researchers cannot necessarily conclude that exercise in the morning is better than exercise in the evening, Jonas Thue Treebak stresses.
'On this basis we cannot say for certain which is best, exercise in the morning or exercise in the evening. At this point, we can only conclude that the effects of the two appear to differ, and we certainly have to do more work to determine the potential mechanisms for the beneficial effects of exercise training performed at these two time-points. We are eager to extend these studies to humans to identify if timed exercise can be used as a treatment strategy for people with metabolic diseases', he explains.
https://www.sciencedaily.com/releases/2019/06/190613095209.htm
Morning exercise can improve decision-making across the day in older adults
Study shows how simple changes to your daily routine is key to good brain health
April 29, 2019
Science Daily/Baker Heart and Diabetes Institute
A study of older Australians has found a morning bout of moderate-intensity exercise improves cognitive performance like decision-making across the day compared to prolonged sitting without exercise.
Furthermore, the study showed that a morning bout of exercise combined with brief light-intensity walking breaks to frequently disrupt sitting throughout an 8-hour day can boost your short-term memory compared to uninterrupted sitting, according to the study published in the British Journal of Sports Medicine.
The 'Brain Breaks' study, led by the Baker Heart and Diabetes Institute and The University of Western Australia, also shows that the distinct responses in cognitive performance to exercise versus exercise and sitting breaks point to different patterns of physical activity being able to enhance distinct aspects of cognition.
The study of more than 65 males and females aged 55 -- 80 years examined the effects of acute morning exercise on a treadmill with and without brief 3 minute walking breaks during an 8-hour day of prolonged sitting, and assessed aspects of cognition and concentration including psychomotor function; attention; executive function such as decision-making; visual learning and working memory.
Central to mediating the benefits of exercise on learning and memory is brain-derived neurotropic growth factor, a protein which plays an important role in the survival and growth of information-transmitting neurons in the brain. The results demonstrated that this protein was elevated for 8 hours during both exercise conditions, relative to prolonged sitting.
Physical activity researcher, Michael Wheeler says the study highlights that uninterrupted sitting should be avoided to maintain optimal cognition across the day, and that moderate-intensity exercise such as a brisk walk should be encouraged for the daily maintenance of brain health.
He says the study also reveals that not all aspects of cognition respond in the same way to a given dose of exercise and that it may be possible to manipulate the pattern of activity across the day to optimise specific cognitive outcomes.
"With an ageing population which is looking to live healthier for longer, these studies are critical to people enjoying a productive and satisfying quality of life," Wheeler says.
"This study highlights how relatively simple changes to your daily routine could have a significant benefit to your cognitive health. It also reveals that one day we may be able to do specific types of exercise to enhance specific cognitive skills such as memory or learning."
https://www.sciencedaily.com/releases/2019/04/190429154529.htm