When is it important to exercise? Cell sub-issue: Early morning or evening exercise, the effect is very different!

Source: Mace Medicine

Life is movement. Moderate exercise not only strengthens the body, but also has a good effect on improving metabolic state and delaying disease progression. However, exercise in different time periods may have different effects, and how to choose an appropriate exercise time is an interesting scientific mystery.

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Although the effect of exercise on energy metabolism has been confirmed, there is still a lack of research on how exercise time affects metabolic state, and we still do not know the similarities and differences of exercise in different time periods.

A recent article in Cell Metabolism answers this question. Using mouse models, they found that exercise does have different effects on local and systemic metabolism at different times of the day.

doi:10.1016/j.cmet.2021.12.016

The researchers divided mice into two experimental groups and had them exercise on a treadmill for 1 hour in the early morning (early light) or evening (early dark), and also set A control group that did not exercise.

Tissues from different parts of the mice were collected after exercise, such as: serum, skeletal muscle, liver, epididymal white adipose tissue (eWAT), inguinal subcutaneous white adipose tissue (iWAT) and interscapular brown Adipose tissue (BAT), etc., perform omics analysis on the metabolite and gene expression status of these tissues.

doi:10.1016/j.cmet.2021.12.016

Each tissue exhibits a unique metabolic response based on duration of exercise. In muscle tissue, exercise in the evening changed 197 metabolites, while exercise in the early morning affected 52 metabolites, and exercise at both times changed 31 metabolites.

In the liver, 129 and 143 metabolites were affected in the morning and evening, respectively, and 101 metabolites were altered in both. In eWAT, metabolites typically decreased after early morning exercise but increased after evening exercise. Therefore, they suggest that the effects of exercise on metabolites are time-dependent and tissue-specific.

Analyzed by metabolite class, amino acids and lipids were more affected by evening exercise. Corticosterone was the metabolite most increased by morning exercise in muscle, heart, eWAT, iWAT, and BAT. Liver maltopentaose, maltotetraose and maltotriose decreased most after morning exercise, while glucose decreased after evening exercise.

doi:10.1016/j.cmet.2021.12.016

Also, corticosterone is increased by exercise in all tissues, but liver and muscle corticosterone levels are highest after morning exercise. Evening exercise increases ketones such as beta-hydroxybutyric acid and urea from ammonia detoxification metabolism.

The research team further performed genetic testing and KEGG enrichment analysis on the altered metabolites. They found that after early morning exercise, the liver exhibited a marked fatty acid metabolic response with a selective increase in fatty acid metabolites. At the same time, the carbohydrate metabolism of the liver is enhanced during early morning exercise, which indicates that hepatic glycogen is the raw material preferentially utilized during exercise in the early morning.

doi:10.1016/j.cmet.2021.12.016

Glucose metabolism, morning exercise reduced liver glycogen content. At the same time, genes involved in glycolysis also increased in muscles after evening exercise. Glycogen that passes through the liver in the early morning, the researchers explainThe energy produced by decontamination and gluconeogenesis is sufficient for exercise, but in the evening, glucose production by the liver may be inhibited, causing the body to rely more on muscle glycogen.

Amino acid metabolism, amino acids were highly enriched in the serum of mice that exercised in the evening, indicating that protein degradation and amino acid utilization increased after evening exercise. Correspondingly, muscle levels of glycine, serine, threonine, lysine, and tyrosine increased after evening exercise, but not after early morning exercise.

Although levels of glycine, serine, threonine, and phenylalanine metabolism in the liver also increased after evening exercise, the liver also showed alterations in amino acid metabolism pathways after early morning exercise. enrichment. The researchers believe that this shows that the liver can dynamically regulate and utilize amino acid metabolism according to the time of exercise.

doi:10.1016/j.cmet.2021.12.016

In terms of lipid metabolism, morning exercise can significantly increase some fatty acids in liver, while evening exercise can increase fatty acids in serum, eWAT and iWAT. Glycerol in liver increased significantly after morning exercise, and glycerol in iWAT increased after evening exercise.

The researchers explain that early morning exercise stimulates lipolysis in the liver, but evening exercise stimulates lipolysis in iWAT.

Acylcarnitine levels in muscles increased after evening exercise, suggesting that evening exercise activates fat oxidation in muscle, and evening exercise increases muscle resistance to glycolysis compared with early morning exercise Other sources of energy are in greater demand.

doi:10.1016/j.cmet.2021.12.016 (this picture is too beautiful)

In general, morning and evening exercise have different effects on metabolism. Early morning exercise mainly supplies energy through glucose metabolism. The liver glycogen reserve is relatively rich, and it is not prone to large fluctuations in blood sugar. It may be more suitable for people with glucose metabolism disorders, such as diabetes and hypoglycemia.

The evening exercise mobilizes more fat breakdown, which may be more suitable for people who lose fat. However, protein decomposition is also more intense during evening exercise, so it is necessary to pay attention to supplementing protein nutrients in time.

The researchers also pointed to limitations of the study, such as mice having a circadian schedule that is opposite to that of humans, which may interfere with the generalizability of the results. In addition, the article did not assess the impact of different exercise methods on metabolism, and the conclusions may not be suitable for all types of exercisers.

Although research is still in its infancy, it suggests that the time period of exercise can have a significant impact on exercise performance. In addition, the study shows that reasonable exercise can indeed greatly improve the body’s metabolic function. Whether running in the morning or running at night, moving is the most important thing.

References:

Sato S, et al. Atlas of exercise metabolism reveals time-dependent signatures of metabolic homeostasis. Cell Metab. 2022, 34(2):329-345. doi:10.1016/j.cmet .2021.12.016.

Writing | Guan Shuimu

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