Exercise is good medicine! Studies have found that "afternoon exercise" can significantly improve insulin resistance!

Introduction: As one of the 5 carriages of diabetes management, regular exercise is an important part of achieving good blood sugar control, but guideline recommendations tend to focus on the type of exercise (aerobic, resistance, etc.
) and total duration of exercise (such as not less than 150 minutes of moderate-intensity aerobic exercise per week), and the question of "when is 'exercise' of the day better for improving blood sugar" is still
debated due to lack of evidence.

As more evidence emerges, this question may have an answer
.
Recently, a study published in the journal Diabetologia (impact factor: 10.
122) showed that focusing exercise in the afternoon or evening, assuming a similar amount of exercise throughout the day, can improve blood sugar control and insulin resistance to a greater extent (18% improvement in afternoon exercise and 25% improvement in evening exercise).

Exercise sugar control, not only to choose the right way, but also to choose the right time

The data were collected from 775 participants in the Dutch Obesity Epidemiology (NEO) observational study, with a mean age of 56 years, a mean body mass index (BMI) of 26.
2 kg/m^2, 42% males, a median liver fat content of 2.
6%, and a median HOMA-IR of 1.
0
.

Moderate to vigorous exercise (MVPA, defined as activity of task intensity >3 metabolic equivalents) was tracked
for four consecutive days by wearing a monitor.
According to every 6 hours, the researchers divided the day into three periods: morning (06:00-12:00), afternoon (12:00-18:00) and evening (18:00-24:00), according to the exercise habits of the subjects, divided into morning exercise group, afternoon exercise group, evening exercise group and all-day balanced exercise group (control group).

The relationship
between exercise time and liver fat content and insulin resistance was explored.

Exercise in the afternoon and evening, insulin resistance improves significantly!

Under the same MVPA total amount of exercise, the insulin resistance of subjects in the afternoon and evening exercise groups was significantly improved, 18% and 25%, respectively, compared with the all-day balanced exercise group.
These benefits
were not found in the morning exercise group.
However, exercise time did not appear to affect the amount
of fat in the liver.

Fig.
1 Effect of exercise time on insulin resistance

Fig.
2 Effect of exercise time on liver fat content

The conclusions are unanimous! Similar studies were released at the 2022 ADA Conference

In June 2022, scholars at the 82nd Scientific Meeting (ADA) of the American Diabetes Association shared similar research results: moderate and high-intensity exercise can effectively improve blood sugar, and "afternoon exercise" has the best
hypoglycemic effect.

The prospective study included a total of 1,755 participants and looked at the relationship
between moderate to vigorous physical activity (bMVPA) and changes in blood glucose levels and glucose-lowering drugs at different times of the day in adults with T2DM.
Participants were randomly assigned to a lifestyle intervention or a control group, with the most intense intervention occurring at year
1.
The study found that:

➤ Reduction in HbA1c, best in the afternoon exercise group: participants in the afternoon group had a greater reduction in HbA1c compared with the inactive group (mean: -0.
16%; 95%CI -0.
33%~0%）；

➤ Discontinuation of hypoglycemic drugs, highest in the afternoon exercise group: Among non-insulin users, the probability of discontinuing hypoglycemic drugs in the first year differed between different bMVPA time groups compared with maintaining or starting hypoglycemic drugs (P=0.
09), and the probability of discontinuing hypoglycemic drugs was also highest in the afternoon group (afternoon exercise group vs.
inactive group: OR 1.
86; 114-3.
02).

The mechanism behind it?

The researchers said that in human biology, the relationship between exercise time and health is a relatively blank field, and the mechanism has not yet been explored
.
Early research suggests that the body's metabolism responds to high-intensity exercise differently
depending on the duration of exercise.
In addition, muscle strength and metabolic capacity of skeletal muscle cells peak in the late afternoon, suggesting that concentrated exercise during this time may bring about a more pronounced metabolic response
than at other times.

However, the researchers point out that exercise time is likely to be only part of the
health puzzle.
Other lifestyles and behaviors (e.
g.
, sleep, timing of food intake) are also important factors in the body's biological clock system, and various factors may interact
with each other.
In addition, the betterment of afternoon/evening exercise does not mean that morning exercise has no health meaning, if you only have time to exercise in the morning, you must stick to it
.

Resources:

[1] Jeroen H.
P.
M.
van der Velde et al, Timing of physical activity in relation to liver fat content and insulin resistance, Diabetologia （2022）.
DOI: 10.
1007/s00125-022-05813-3

[2] Afternoon or evening physical activity is linked to reduced insulin resistance, better control of blood sugar.
2022-11-1.
https://medicalxpress.
com/news/2022-11- afternoon-evening-physical-linked-insulin.
html