Low intensity exercise or high intensity exercise – which is better for fat loss? Ever since interval training started gaining popularity in the workout world a few years ago, the debate of low intensity exercise vs high intensity exercise has never seemingly been settled. There are arguments (and even studies) that support both sides, but below you’ll find five reasons the easier workload should win out.
If you’ve ever looked at a cardio machine, you’ve likely seen one of those little charts that says at what heart rate you should work at in order to be in the “fat burning zone”. While these charts, as well as the digital readouts on cardio machines, are educated guesses at best, there still is something to the idea.
This is because at a lower intensity, the body likes to use fat as fuel. When workout intensity rises, the body prefers to switch over to burning carbohydrates. Now it’s not a complete “either/or”, as you’ll still burn some of each, no matter how hard you’re working. However, if you want to predominately keep your calories burned coming from fat, you’re better off doing easier work.
To be truly effective, exercise (especially cardio) duration and intensity should be inversely proportional. In other words, you should work long and easy or short and hard. To use a real life example, it would be appropriate to say you can jog a 5k or sprint 100m, but you can’t sprint a 5k and jogging 100m is pretty much useless.
The problem many gym-goers have when they do higher intensity exercise is that their effort level is often more akin to a jog than it is a sprint. Most underestimate the sheer effort required to make exercise high intensity, therefore end up not working as hard as they think they are. The only true way to measure intensity level is by monitoring VO2 max, and most people don’t have a way to do this.
On the other hand, low intensity exercise is impossible to do incorrectly. This is because you don’t have to maintain a particular intensity level. As long as you’re doing enough total work volume, you’re good to go.
Most proponents of high intensity exercise for fat loss like to point out how a workout can “rev up” your metabolism, burning calories for several hours after your session is over. This is via a mechanism called EPOC – excess post-exercise oxygen consumption.
Now while this is true, what many of these same people fail to realize is that low intensity exercise benefits from EPOC, as well. Low intensity EPOC is only about half of high intensity EPOC (7% of calories burned during a workout vs 14% according to the Journal of Sports Sciences), but remember the point above about getting intensity level “right”.
When done properly, high intensity workouts don’t last nearly as long as their low intensity counterparts. Therefore, they don’t burn nearly as many calories. Read more about aerobic vs anaerobic training here (which explains more about EPOC).
As long as repetitive ballistic shock (e.g. – jogging on pavement) is kept minimal, low intensity exercise is generally easier on the body than higher intensity exercise. This means injuries are fewer and further between and overtraining is less likely. Since long-term workout consistency is critical for success no matter the goal or program, staying healthy means you have a better chance of training regularly over the long haul.
This might seem counter-intuitive, as the general consensus with lower intensity exercise is that when properly done, it takes a long time. The thing you have to remember is that low intensity exercise doesn’t necessarily have to be exercise – it can be any low intensity activity that bears the same sort of physical attributes. Then consider that cumulative work performed is more important than how much you do at any one time, and you realize that many daily activities could help you lose fat.
For instance, taking your dog on a daily walk, walking across campus between college classes, or practicing soccer with your kids or young siblings could easily add a couple hours or more of easy exercise-like activity every week. The great thing about this is that you get the exercise benefits without having to add any additional time in the gym or doing cardio.
Though it flies in the face of what many popular notions and experts like to say, easier exercise goes a long way toward burning fat. This doesn’t mean you should totally forego harder work, but keep your focus on the lower key stuff. The EPOC is better than you think, it’s pretty much impossible to do wrong, you likely won’t get hurt, calories you do burn are more likely to come from fat, and it can be quite easy to work into your daily schedule.