What Time You Exercise Matters

Science shows morning and afternoon exercise may be best, especially for preventing the risk of type 2 diabetes.

If you want your pilates or jogging to pack an extra health punch and lower the risk for type 2 diabetes, research indicates the time of day you exercise does matter. No one questions the numerous benefits of exercise, but does the timing of the effort make a difference?

A new study published in Diabetologia revealed that morning and afternoon physical activity seems to decrease the risk of developing type 2 diabetes, but not so with evening exertion.

“The timing of activity may play a role in mitigation of diabetes risk,” the study authors noted.

Not only was morning and evening physical activity protective in preventing the development of type 2 diabetes, but compared to evening workouts, those who logged more total hours of physical activity had less risk of developing the disease. In addition, the harder the workout, the more protective, the Harvard researchers led by Dr. Caiwei Tian and Dr. Chirag Patel revealed.

The British participants, 93,096 of them from the UK Biobank, agreed to wear an accelerometer for one week to record their physical activity, a new way to objectively measure exertion throughout the day. In this way, all exertion was recorded, including household chores like vacuuming and sweeping and outdoor tasks such as raking and mowing.

Another of the study’s findings was that while overall MET hours — a common measure of physical activity — were associated with a lower risk for type 2 diabetes, it didn’t matter how those hours were gained. In other words, whether the time added up from scattered 10-minute intervals or longer dedicated stretches of a workout, it didn’t have an impact if the final amount of time exercised was the same.

The results suggest getting at least two and a half hours each week of moderate to vigorous physical activity, preferably in the morning or afternoon, as the best way to protect from developing type 2 diabetes, the authors concluded. Avoiding long sedentary periods is also important.

How exercise helps type 2 diabetes

“The long-term benefits of exercise on blood sugar and insulin health are unquestionable,” Rasa Kaziauskalite, MD, associate professor of endocrinology, diabetes, and metabolism at Rush University Medical Center in Chicago, said in a statement to Everyday Health.

Exercise enhances insulin sensitivity, so glucose is more readily used as an energy source, resulting in lower blood glucose levels. Multiple studies document this.

For example, eight weeks of training that included one hour of aerobics three times a week restored insulin sensitivity, improved metabolism, and resulted in a loss of abdominal fat and weight, according to a recent investigation published in JCI Insight.

Exercise also reduces dependence on glucose-lowering oral medications and insulin, a study review found. Additionally, research shows that increased physical activity can even help reverse prediabetes.

Why is the morning best?

The mechanism is not entirely clear. Most scientists think that morning or afternoon exercise may better regulate the circadian rhythm — the body’s natural clock that influences many biological processes, including metabolism. This natural clock affects insulin sensitivity, hormone secretion, sleep quality, and other factors important for controlling weight.

Evening physical activity might simply disrupt our body clock and alter glucose metabolism and tolerance.

Other great benefits of a morning workout

Burns more fat: If you train straightaway upon awakening, chances are your body is in a fasting state. Aerobic exercise in a fasting state caused higher fat oxidation than exercising in a well-fed state, resulting in more fat burning, according to an investigation of 27 prior studies which included 273 participants,

Suppresses appetite: Women who walked briskly on a treadmill for 45 minutes in the morning showed less interest in food images afterward, which lasted throughout the day, revealed a BYU study. The women also didn’t eat more calories to make up for the energy burned.

Creates more afterburn, resulting in more calories used: There is evidence that afterburn — increased oxygen consumption after a workout — lasts longer after a morning workout, as compared to later in the day, which leads to more calories burned. For instance, a small 2019 study of men who joined a conditioning program to lose weight revealed that those who trained in the morning lost more pounds than those exercising later in the day, even though everyone completed the exact same exercise routine.

How to become an early bird

Dragging yourself out of bed at seven am and walking on a treadmill at a moderately strenuous level (65% to 75% of maximum heart rate) for three consecutive days can shift your circadian rhythm, according to a study on human circadian response to exercise. As a result, you’ll become tired earlier in the evening and go to bed earlier until your physiology eventually adjusts to getting up with those sunrise mornings.

Also, morning habits are easier to establish. Researchers studied the effects of cortisol on developing health habits. They found that a group trying to adopt a healthy morning habit could do so fifty days earlier than a similar group that introduced the routine later in the day. That’s seven weeks earlier. Getting out of bed earlier as a routine may take less time than you think.

Although the study in Diabetologia showed that morning and afternoon physical activity appeared to decrease the risk for type 2 diabetes, while evening activity did not, and it might be a better time choice for a workout if you have or are at risk for diabetes, the point is to get active.

Dan Gallagher, a registered dietician with Aegle Nutrition in Texas, said it best when he told Medical News Today:

“The bigger point is that you’re working out at all. Whatever time of the day helps you get your workout done is when you need to schedule your workout.“

Annie