It’s a question as old as time (or the stationary bike, at least): Is there a best time of day to work out? The consensus has long been diplomatic, with health and fitness experts generally agreeing that the optimal time to exercise is whenever you can fit the gym into your schedule. (It’s sage advice, though there are some important do’s and don’ts that late-night gym-goers should keep in mind). 

However, if weight loss is your primary goal, new research suggests you should set an alarm and get to the gym first thing in the morning before tackling your inbox or running off to any appointments. In fact, a recent analysis published in Obesity found that crushing moderate-to-vigorous workouts in the a.m., specifically between seven and nine o’clock, is most strongly correlated with weight-loss results. 

• ABOUT OUR EXPERTS: Austin Martinez, M.S., C.S.C.S, is a trainer and vice president of education for StretchLab. Kelsey Costa, M.S., R.D.N., is a dietitian and a consultant for the National Coalition on Healthcare. Brittany Werner, M.S., R.D.N., C.P.T., is a dietitian, personal trainer, and the director of coaching at Working Against Gravity. 

The Research 

Many past studies have focused on what type of workouts to do for weight loss. (Spoiler alert: Resistance training for weight loss wins!). Until now, though, not much large-scale research has focused on when to work out to maximize your weight-loss goals. 

For the newly published analysis, researchers evaluated 2003-2006 data from the Centers for Disease Control and Prevention’s health and nutrition surveys, which involved 5,285 adults who wore accelerometers to monitor fitness activity.

The results showed that those who worked out in the morning tended to have lower body mass indexes (BMIs) and waist circumferences than those who worked out midday or in the evening. The morning cohort also trended toward healthier diets and consumed fewer calories throughout the day, according to self-reported nutrition logs. They were also the most likely to work out at the same time every day, according to the study.

Interesting stuff, right? This research confirms what some fitness professionals have long preached: “Morning workouts have an edge,” says strength and conditioning coach Austin Martinez, M.S., C.S.C.S, vice president of education for StretchLab. “There are physiological benefits to working out in the morning, such as increased blood flow, which helps with mental capacity and prepares the body for the day ahead. It tends to energize you, too.” Plus, as the day goes on, work deadlines, traffic, and other curveballs can diminish your motivation to work out later on, he notes. 

Another interesting finding here is that those who worked out in the morning were more sedentary overall than the others in the study, points out dietitian Kelsey Costa, M.S., R.D.N., a consultant for the National Coalition on Healthcare. “It suggests that the timing of exercise—specifically engaging in physical activity in the morning—may aid weight management and potentially counteract the impact of sedentary time during the rest of the day,” she says. That’s a pretty big deal considering how sedentary the average person is these days.

One thing to note, though: While BMI, a ratio of height to weight, has long been considered a key indicator of a person’s health, there is debate on its usefulness as a health metric. Many experts suggest that other factors, like blood-glucose levels and waist circumference (which was also measured in this research!) help to paint a fuller picture of someone’s health.

Tips for Working Out In The Morning 

Want to maximize the weight-loss benefits of early-morning exercise? Combine or alternate between cardio and resistance training for an effective, full-body regimen, recommends Costa.

“While cardio workouts help burn calories and improve cardiovascular health, resistance training aids in building muscle mass, which boosts your resting metabolism and leads to increased calorie burn throughout the day,” she says.

Since early morning workouts typically mean you don’t have a lot of time for proper digestion, Werner advises sticking to quick-digesting carbs and lean protein for pre-workout fuel. 

A few suggestions:

• Rice cakes with peanut butter powder and honey (plus a bit of regular PB if you need some healthy fats)
• A banana and whey protein shake (plus a handful of almonds if desired)
• A smoothie with fruit and yogurt (plus avocado or nut butter if desired)
• Egg white muffins and a slice of toast (plus butter if desired)
• Overnight oats

Following your workout, eat a combination of protein and carbohydrates, advises Costa. Protein assists in muscle recovery and growth, while carbs replenish the body’s glycogen stores and optimize recovery post-exercise. Consider a protein smoothie with fruit, scrambled eggs with sweet potato home fries, or chicken and rice with vegetables.

The Takeaway

Research shows a strong link between morning exercise and a healthy body weight. But that doesn’t mean a.m. workouts are do-or-die for results. And, frankly, they’re just not possible for everyone. 

Worth noting: Those who are able to work out in the morning on a regular basis could have more predictable schedules, points out dietitian and trainer Brittany Werner, M.S., R.D.N., C.P.T., director of coaching at Working Against Gravity. They might be less likely to be shift workers or perhaps don’t have other responsibilities that get in the way of morning exercise. 

“We know that routine, a quality sleep schedule, and overall predictability in our daily lives can have other advantageous effects on body weight that were not measured in this study,” she points out. 

So, if you’ve got the flexibility in your schedule to hit the gym in the morning, great! This research suggests it could be a win for shedding pounds. However, don’t sweat it if you’re just not an early bird or your schedule prevents you from working out in the a.m., Werner says. “The most effective workout schedule is one that fits with your lifestyle. It’s important that your training time be conducive to your other obligations and a time that you look forward to each day—otherwise, you’re unlikely to continue.” Squeezing your workouts in at random times or waiting until the kids go to bed is still a-okay if it keeps you consistent.