A friend who knows I read a lot, and that I recommend the Susan Powter approach to weight loss asked me whether she might be eating too few calories. She said she hadn’t felt very good the previous day, and had a loss of appetite. She had only consumed 1200-1300 calories of low fat food, and she had worked out for an hour and forty minutes. She was concerned that see might be burning muscle instead of fat.

I told her that when you eat less calories than you burn, you lose weight. In fact YOU HAVE TO eat less calories than you burn to lose weight. You need to burn 3500 more calories than you eat just to burn one pound of fat.
When there is a deficit, your body goes to the easiest source of fuel, your body fat (kind a fuel storage system). It will burn the fat, before it goes after muscle. If you go too low on calorie intake, your body might turn to muscle, but you would probably have to go really low. You body does need glyogen (sugar) to aid in the burning of the fat. Kind of like lighter fluid to get the charcoal burning. When you hear about people hitting The Wall, they have depleted their stores of glycogen.
I told her to keep eating healthy, and working out. You are doing a great job!

I recommended that she train with a heart rate monitor? With an HRM, you can train efficiently, and stay aerobic where your body is burning mostly fats. As you go harder into the anaerobic zones, you body can’t burn fat fast enough, so it swtches gears, and starts burning more glycogen, and less fat. Your body also starts producing lactic acid faster than you can get rid of it. Lactic acid starts breaking down the muscles. When you break down muscles like this, you need to rest for at least 48 hours for the muscles to rebuild. If you do alot of hard anarobic workouts abck to back with no rest, you are breaking down your muscles, and not giving them a chance to rebuild. This is a major cause of injuries.

Keep in mind, I am just regurgitating things I have read. There are lots of people on the message boards who are far more expert then me. But then I also dropped my own weight from 230 to current 170, and am one of the most physically active people I know. So I must be doing something right.

Posted by Rob in Nutrition on April 5th, 2007 |