Researchers concluded that 30 minutes of daily training was as equally effective at shedding the pounds as 60 minutes worth of sweating.
The University of Copenhagen study concluded that sweating for half the time was enough to turn the tide for obesity.
The research, published in the American Journal of Physiology, found those who ran, rowed, or cycled for 30 minutes a day lost an average 8lb over a three month period.
In comparison, men who pushed their daily training routine out for an hour lost two pounds less.
Mads Rosenkilde, who led the study, said: Training is fantastic for your physical and mental health. The problem is that it takes time.
In their study researchers followed the progress of 60 Danish men, considered heavy but healthy but who wanted to get fit and in better shape over three months.
Half of the men were asked to exercise for an hour a day, wearing a heart-rate monitor and calorie counter, while the second group only had to sweat it out for 30 minutes.
His team concluded that just 30 minutes of exercise hard enough to produce a sweat was enough to turn the tide on an unhealthy body mass index.
The participants in our study trained every day for three months, said Mr Rosenkilde, a PhD student from the department of biomedical sciences.
All training sessions were planned to produce a light sweat, but participants were expected to increase the intensity and give it gas three times a week.
Participants exercising 30 minutes per day burned more calories than they should relative to the training program we set for them.
He added: In fact we can see that exercising for a whole hour instead of a half does not provide any additional loss in either body weight or fat.