The Best Exercise for Losing Weight

News of the latest study from Duke University claims to settle what some refer to as a decades-old debate - which type of exercise: classic cardio, strength training, or a combination of the two is the best for losing weight?  “An 8 month study that followed 119 overweight volunteers found that cardio was the winner!”  That’s the simple answer, but not the whole story.  Let’s use some critical thinking and research to take a deeper look into this revelation.

First, they were not using a very large sample size, and we find out the 119 subjects were split into three smaller subgroups of about 40 each.  Cardio did provide the best results but the group that did both “actually had the most improved ration of fat-to-lean muscle mass.”  In an attempt to decide if it’s one or the other, they conclude that the best answer is both – pretty anticlimactic.

But pay close attention to the subtitle of the article:  “Don't forget to make healthy food choices too.”  Exercise alone isn’t the answer.

The big mystery, though, is why they presented this as a decades-old debate.  Another very thorough article on the subject from the WebMD archives dated 2007 tells us, “In all cases, however, you'll burn more calories with cardio (aerobic) exercise than with strength or resistance training.”

Then they come to pretty much the same conclusion about the benefits of doing both and top it off with:  “Eating and exercise are not separate issues…Too many people think these large doses of exercise are an excuse to eat whatever you want."

Which takes us to an NPR segment from six months ago on the results of long-term research looking at the effectiveness of wearable technology, specifically those fitness monitors.  “The 470 people in the study were put on a low-calorie diet and asked to exercise more. They all started losing weight. Six months in, half the group members started self-reporting their diet and exercise. The other half were given fitness trackers to monitor their activity.”  Researchers were surprised to find that after two years, reporting equal amounts of physical activity, the group with the fitness trackers lost less weight.”

A possible explanation for this difference is related to a theory of behavior called risk compensation (later renamed risk homeostasis).  The theory was developed to “explain the fact that people adjust their behaviour in the face of interventions.”  Often used to explain why making cars safer causes some drivers to take more risks and adding padding to playgrounds results in wilder play among some children, risk compensation can also refer to how a technological monitor could cause some dieters to eat more than they otherwise might have.  They are more easily tempted to offset the more visible effect of the exercise by snacking a little more.

This brings us full circle.  There was never any need for a debate or for a new study.  We’ve known for at least 10 years that cardio burns more calories but cardio and strength training work well together.  But any exercise alone is not enough.  It’s well known that healthy eating is top priority and that it’s much easier not to eat calories than to burn them off through exercise.

Finally, the same wisdom applies to both exercise and dieting.  The best exercise for you is the one you will do.  The best diet is the one you will stick to.  Nothing new here!