If exercise is good for losing weight, more must be better, right? Not according to new research carried out at the University of Copenhagen in Denmark. At least in this study, exercising longer didn’t lead to more weight loss. One more reason to increase the intensity of your workouts rather than their duration.
Researchers divided 60 overweight men into two groups. Both groups exercised at a moderate pace by either running or cycling. The only difference was the amount of time they exercised. One group exercised at a moderate intensity for 30 minutes a day while the other group worked out for a full hour. During the study, researchers followed their body weights closely. At the end of the 13 weeks study, the group who worked out for 60 minutes a day lost an average of 6 pounds. Surprisingly, the group that only sweated 30 minutes a day lost more weight. On average, they lost 8 pounds.
Why More Exercise Won’t Necessarily Lead to Greater Weight Loss
Intuitively it would seem that the group that exercised for 60 minutes, twice as long as the other group, would have experienced more weight loss. After all, they expended more calories. Why didn’t it work this way?
Several issues could be at play here. For one, more prolonged exercise sessions may have stimulated their appetite and motivated them to eat more. It’s not hard to compensate for the additional calories you burn through exercise with diet. For example, if the men ran at a 10 minute per mile pace, the group that exercised for an hour would have burned around 540 calories, while the group that ran 30 minutes would have expended 270 calories. This 270 calorie differential wouldn’t be difficult to compensate for by eating a little more during the day. That’s why some research suggests that exercise alone doesn’t lead to significant amounts of weight loss in people who are overweight. Diet and nutrition are equally, if not more, important than how long you exercise, especially when you’re working out at a moderate pace where you don’t experience a significant afterburn effect. Also, keep in mind that studies on humans are difficult to control as participants usually don’t exactly follow the nutrition and exercise program they’re supposed to do in the study.
Another Reason Why Longer Periods of Exercise Don’t Lead to More Weight Loss
Another way some people compensate for longer exercise sessions is by expending fewer calories later in the day. After a long workout, you feel more fatigued. This could make you less motivated to get up and move around the rest of the day so you’d burn fewer calories than you normally would during your daily activities. It’s your body’s compensation mechanisms at work again.
What Does This Mean?
More exercise isn’t necessarily better when you’re trying to lose weight. It’s easy to make up for the additional calories you burned by working out an extra 30 minutes by eating a little more. You may even feel “entitled” to eat more since you exercised so hard. Plus, you may unconsciously slow down the pace of your activities for the rest of the day.
Instead of doing a longer routine, use the time you currently exercise more efficiently – by increasing the intensity. High-intensity intervals will force your body to burn more calories even after you’ve finished as you expend more energy during the recovery phase. When you factor in the hormonal effect of shorter, more intense exercise, including greater increases in growth hormone and testosterone, you’ll ultimately burn more body fat when you work out harder for shorter periods of time. But since you shouldn’t do high-intensity interval training more than two or three times per week you can still mix in your longer steady state cardio workouts into your weekly workout schedule. This will help you to avoid overuse injuries and will keep your body constantly challenged in different ways.
Strength Training Should Be a Priority Too
This study only looked at aerobic exercise, and strength-training is no less important since it builds metabolically-active lean body mass that helps you burn more fat over the long run. You may need to work out more than 30 minutes a day so you can fit in an appropriate amount of strength-training but use that time to focus on strength exercises rather than spending another 30 minutes running or cycling. Ultimately, you’ll get more benefits when you balance cardio with resistance training. Lastly, don’t forget the importance of nutrition. If you’re trying to lose weight, keep a food journal to see when you’re compensating for exercise by eating more.
The Bottom Line?
More isn’t always better when it comes to aerobic exercise. Increase the intensity of your cardio sessions and keep them shorter. Then balance it out with strength-training for a strong, lean physique.
References:
EMedicineHealth. “Thirty Minutes of Daily Exercise Enough to Shed Pounds”
American Journal of Physiology News Release. August 1, 2012.
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Love, love, love, this aricle I was just telling a friend this same thing when it came to her running, she thought doing more miles will help her lose more weight and I told her “it’s not how far you run, but how fast you run!”
Thanks again Cathe!
I’ve been saying this for a few years now. I also think, I know for me, that exercising longer raises my stress hormones. Once I cut back, my blood work results went back into normal ranges. When I tell other exercisers that i stick to 30 minutes in general, sometimes a little more if I do both cardio and strength, I get some pretty ugly responses including being called lazy, unmotivated, unhealthy, and slothen. It’s nice to see that what I’ve known personally is being validated by research.
This is surprising news to me since recently, I had kicked up the duration of my cardio workouts on my elliptical (and trying to maintain the same high intensity as I did in the shorter durations) and wondered why I’ve been so tired all the time. I’ve been thinking about going back to the shorter workout times but was afraid that I would then lose tone/fitness.
Weightloss isn’t a big concern for me right now as I am at my goal weight so, my question is this: is there any benefit, other than weight loss, to doing longer duration cardio workouts? Should I be mixing up my workout sessions with longer durations on some days, shorter on others? I also do strength and core training in addition to cardio on the elliptical. Very interesting article!
This article made a lot of sense to me. I have been a cardio junkie (2 hours daily!) for many many years and have been looking for proven reasons why I shouldn’t do so much cardio. I also weight train but for far less time during each week (2 hours+, twice a week). I, too, would like any suggestions on how to best mix things up. I need all the advice I can get to help convince me to do less cardio and balance things out better.
I know this is true. For 7 years I biked 15 miles 5 days a week completing the ride in just under an hour. I found that I was slowly gaining weight.
I started doing a difficult cardio routine, (while holding a 10 lb. medicine ball, I do a deep squat then lift the ball above my head — do this continuously 32 times — then a minute rest and repeat 8 to 10 times). I also started doing more weight lifting.
This change in exercise, along with cutting out most carbs, I was able to lose 20 pounds in 6 months (and not feeling like I was on a restrictive diet.)
Some days I just love longer workouts because they are fun. But some days I just do not have the time. Now I know why some days I feel more fatigued when I do a 90 min to 2 hour workout! Great article!
Well…this was an article about men. Not to say it doesn’t apply to women, but I’m tired of this blog publishing mostly studies done on men. How about studies on perimenopausal women when weight gain becomes such an issue?
Also, this study didn’t track calories consumed, so I think its fairly unscientific as to what caused the weight loss difference.
Well, the basic line” regular moderate instensity” said it all for me.
We all know men lose weight at a faster rate than women anyway, so while I understand the higher intensity for a shorter period of time ( 30 min vs. 60 min.), I don’t like that they didn’t include the resistance training
for the study. Why wouldn’t you include this factor in the study? All of the newest workouts are including body resistance or other types of resistance in the quotient to get better results at shorter bouts of time. Maybe the study would have shown better weight loss results.
Plus, anytime I or anyone works out, the result is to feel better — love the endorphin rush. A feat of accomplishment, the look better in the mirror feeling… ahhh. Overall, it was a good study.
I think this article is good in that it reinforces the need to change up your routine and it is fine if you want to do a day or two of a long cardio. However, switch that off for days with a 30 min HiiT workout. Also, include weights and there are weight workouts I do that are 30 minutes in length and killer! Interval training/circuit training for 30 minutes is a great way to get your exercise, and not worry about whether you should do more. Listen to your body. Don’t do the same hour long cardio every day. Change it up with shorter HiiT, circuit or interval training and don’t forget weights. Your body will thank you in the long run.I find on days I workout I eat better and am not as hungry. If all you can do is 30 minutes…then, DO IT! and don’t feel guilty.
Just curious, do any of you all stick to shorter workouts daily (30-45 minutes)? I have a hard time thinking that 30 minutes is enough especially when I have time for a 60 minute workout.
@ Beth
I hope you don’t think we’re favoring studies done on men? We’re just reporting on studies that are published in all of the leading medical and fitness journals. I think you will find that in general there are way more studies done on men than women in the medical field. This is slowly changing, but it is probably is still true today. We have published a lot of articles that that are based on studies of both men and women as well as women only on this site. What the exact ratio is, I don’t know, but we can only report on studies that are published no matter whether or not they were done on men or women only.
As for a study concerning perimenopausal women, we actually published an article on this last week.