Calories In, Calories Out


Posted by Lori O'Donnell

Jun 13, 2018

bigstock-sport-fitness-lifestyle-and--192194854Is it just me, or does anyone else think their fitness watch or fitness tracker gets a little pushy at times? Don’t get me wrong…I love my watch. And, I move. A lot. (I run, train, and teach 8-10 classes a week.) And yet… “Lori, your rings are usually much further along at this time of day. See if you can move a little.” “You’re close to closing your rings! A brisk 20-minute walk should do it!” “Let’s add 50 calories to your daily expenditure goal!” Don’t get me wrong. Like I said, I love my watch. And the reminders to move during the day when I’m sitting at the computer definitely help.

But, a recent study conducted by researcher Nigel Harris shows that while caloric burn is important, looking beyond calories and focusing on metabolism, hormones, and body composition is crucial for maintaining weight.

The study, published in the Journal of Science and Medicine in Sport, set out to establish that while the usual calories-in versus calories-out model can help people lose and maintain their weight, it isn’t the only factor. The results of this research demonstrate that resistance training can trigger greater hormonal and physiological responses in the body than cardiovascular workouts alone. And, that these changes and responses result in positive long-term body composition effects, like weight loss and maintenance.

The first hormone measured was Human Growth Hormone (HGH), which oxidizes fat and builds lean muscle tissue. HGH is important for ongoing calorie expenditure because muscle burns more calories than fat. The more muscle you can build, the more calories your body will burn in the long run. HGH was 56 percent higher after a resistance training or high intensity interval workout, in contrast to a cycling workout of the same duration and burning the same number of calories. 

Blood lactate levels were up to 81 percent higher from resistance training as opposed to cycling. Lactate levels build when the muscles work hard. And, the accumulation of lactate, caused by exercising above the lactate threshold for more than 10 minutes, actually sparks the Human Growth Hormone response.

So…what does that mean for us? In a nutshell, the research proves that resistance training and high intensity intervals generate a greater increase in the body’s fat burning response than simple calorie counting suggests. Our fitness trackers are great for getting us up and moving, and it’s tempting to measure everything we do by the number of calories burned. But, this study shows that it’s not just the number of calories burned. It’s the way we burn them.

Do calories still count? Yes; and for some people, to a greater degree than others. But, hormones are more important. The more you can tap into your body’s hormone responses, the more likely you’ll be able to see longer term physiological benefits. And that makes the workout worth the effort.


Lori O'Donnell is a Group Fitness Instructor at Merritt Clubs Towson.







Topics: calories and weight loss