We have been told that the way exercise can help with fat loss is because moving vigorously burns more calories than being inactive.
Although this is true, it is only part of the story.
Yes moving burns calories but it also does something much more important... it sends a signal to the body. That signal is telling your body to adapt!
When you exercise with sufficient intensity it is a stress to the body. The body senses this stress signal and it aims to become more resilient to this stress so that next time the same activity doesn’t produce the same stress.
This is why you get better at exercise when you are consistent. When you first do cardiovascular activity you breath hard, your muscles burn and it is just plain difficult but over time it gets easier… this is your body adapting.
Since cardiovascular activity doesn’t require lots of muscle your body simply reduces muscle mass as part of this adaptation. This is why long distance runners have skinny stick legs. In fact over time doing tons of cardio will even change hormone profiles to further slow your metabolism down.
So tons of cardio actually slows down your metabolism. This is why when you do lots of cardio you lose weight at first…but then it all comes to a grinding halt. Your body has become more efficient and is literally holding on to body fat to make you better at storing calories and it becomes better at burning LESS calories.
Don’t freak out…there is a different form of exercise that does the exact opposite. Weight training. When you lift weights you send a signal as well…except this time the signal says get stronger. However, if you pick up heavy things, and eat a caloric deficit (and eat the right kinds of food – actual healthy foods), your muscles will get stronger and denser; you will burn the fat on top of your muscle, and you will get that “toned” look that you’re after.