Morning Exercise May Offer the Most Weight Loss Benefits
A new study of workouts and waistlines, found that people who exercise in the before noon seem to lose more weight than people who complete the same workout later in the day.
These results help better our understanding on this baffling issue of why some people lose considerable weight with exercise and others almost none. It also adds to all the scientific evidence that suggests that the timing of different activities, including exercise, plays a role on how those activities affect us.
The relationship between exercise and body weight is somewhat confusing. Many previous studies have shown that people who exercise to lose weight drop fewer pounds than would be expected, given how many calories they are burning during their workouts. Surprisingly, some even gain weight.
However, few respond well, losing pound after pound with same exercise regimen that provokes others to add inches.
This irregularity puzzles Erik Willis, a data analyst with the Center for Health Promotion and Disease Prevention at the University of North Carolina at Chapel Hill.
For almost a decade, he and colleagues at the University of Kansas, the University of Colorado Denver and other institutions have managed the Midwest Exercise Trial 2, an extensive study of how regular, supervised exercise influences body weight.
The study included around 100 overweight, previously inactive young men and women who worked out five times a week at a physiology lab, jogging or otherwise sweating until they had burned up to 600 calories per session.
At the 10 month mark of this study, almost everyone had dropped pounds. But the degree of their losses fluctuated outrageously, even though everyone was doing the same, directed workouts.
They found surprising differences in a study conducted in 2015, where researchers tried to investigate what distinguished the biggest losers from those who had lost less. Some of the participants ,especially men, had begun eating more than before the study began, but only around 100 calories or so a day.
This author, Flummoxed, Dr. Willis, started brainstorming other possible, perhaps unexpected contributors to the enormous variability to weight loss.
They found that activity upon timing played a role.
The science of chronobiology is growing topic of interest. It is the study of how the timing of activities alters how our bodies respond. Many previous research looked at how meal timing, for instance, affects weight control, including whether exercising before or after breakfast matters. But there is very limited research about whether the timing of exercise, by itself, effects whether people lose weight with workouts.
So, for the new study, which was published in July in The International Journal of Obesity, Dr. Willis and his colleagues examined their data again, this time regarding when people in the Midwest trial had shown up at the university lab to exercise.
In that study, participants could visit the gym whenever they wished between 7 a.m. and 7 p.m. They had to sign in each time, so researchers had accurate information about their schedules. They also tracked the participants’ calorie intakes and daily movement habits throughout the 10 months, using activity trackers and liquid energy tracers. So they knew whether and by how much people’s weights had changed.
When they examined weight change against exercise schedules, they noticed a consistent pattern.
On average, people who typically worked out before noon had lost more weight than then men and women who typically exercised after 3 p.m. (participants were unlikely to go to the gym between noon and 3 for unknown reasons.)
They also found that early-exercise groups were slightly more active throughout the day, taking more steps in total than those who worked out later. They also ate a bit less, although the difference was barely 100 calories per day on average. Although the differences were not apparent, they may cumulatively have contributed to the striking differences in how many pounds people lost, Dr. Willis says.
This study was not large or intended from the start to investigate the chronobiology of exercise and weight. They did not randomly assign people to work out at particular times, so the association between exercise timing and weight loss found in their re-analysis may be odd accidents related to individual participants’ preferences and schedules with little relevance for the general population.
However, the statistical relations were strong, Dr. Willis says. “Based on this data, I would say that the timing of exercise might — just might — play a role” in whether and to what extent people drop pounds with exercise, he says.
But he also points out that most of those who worked out later in the day did lose weight, even if not as much as the early-exercisers, and almost definitely became healthier.
“I would not want anyone to think that it’s not worth exercising if you can’t do it first thing in the morning,” he says. “Any exercise, at any time of day, is going to be better than none.”
For additional information please explore the International Journal of Obesity.
Questions: Do you notice a difference when you exercise at different times? Do you think that exercising early makes you consume more food throughout the day? What sort of exercise routines do you do?
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