As I have been working full-time as a personal trainer, I’ve noticed quite a few things that seem to come up over and over again. I admit, they are myths I used to believe myself.
Today is the first one, the myth of incessant cardio for fat loss..
This one is personal- I’ve believed this, too! The truth is that I’ve, especially in the past, loved steady-state cardio. I like that it’s easy, that you can just put shoes on and head out the door.. or go to the gym and catch up on music videos or whatever is currently showing on E! (especially exciting when you don’t have cable at home!) with the knowledge that you’re doing something healthy at the same time. Sometimes you (and by you, I am talking about myself) want to go to the gym and just not think. Cardio is the perfect way to do this. You feel like you must be burning a lot of calories and fat and you’re on your way to a thinner body by each minute you spend on the machine. Sadly, this is often incorrect.
I’ve noticed the difference in my own body in running a LOT vs. running less and lifting weights. Rachel Cosgrove has an article emphasizing exactly that from her Ironman triathlon training. She says that she hardly lost ANY weight in her training, even though she’d often work out for 8 or 9 hours at a time! Unfortunately, muscle turns to body fat, when you are exercising for that long. She states that you have to determine your goals. Are you planning on training for an event? Or are you trying to lose fat? Unfortunately, they are not the same goals and they do not achieve the same results. Both require different preparation.
There doesn’t appear to be a magic number of minutes in which cardio begins to burn muscle in addition to fat, though I read to rarely do more than 45 minutes at a time, recently. Are you frustrated with your body despite a decent diet and gym visits? Re-evaluate what you’re doing. If you are wanting to train your heart for an event, continue what you’re doing. If you are trying to lose fat, it is more important to lift weights and do short, intense cardio than to do a LOT of cardio, especially at a steady state. Most people would not mind being at the gym for less time. You’re allowed! Just make what you do count. If you are the cardio king or queen, try mixing it up. Lift some weights, switch your hour on the eliptical machine for 20 minutes of things like intervals, sprinting, jump rope, stair climbing, and/or jump squats. See the difference in your workout and in your body.

My dad and me at the 2009 Cooper River Bridge Run
As much as I wanted to run a lot, all of the time, I have discovered, in the past year, that if fat loss is a goal.. running a lot burns fat AND muscle. I met with a woman yesterday who has been doing 1.5 hours of cardio every time she comes to the gym. She enjoys it, because it allows her to sweat out her daily stress… but she has lost only a minimal amounts of weight.
At my gym, we’ve changed our new client assessments recently to include a cardio test. With all new clients, we put them on the treadmill, increasing the incline and speed until they cannot speak more than choppy sentences while walking. We’ve found, time and time again, that many people don’t know what it feels like to work hard and they’ve not been maximizing their time.
From a personal example, my body is smaller, since spending months of not doing more than a few hours of cardio a week. I am, though, ramping up my cardio again. After quite a hiatus, I’ve replaced my running shoes and started doing more mileage, in preparation for my seventh annual Bridge Run, and a hopeful not embarrassing time. This time, for the first year, I am adding more interval speed work and less volume training. We’ll see how it goes. I’m not thinking this will be my fastest year, but I have certainly missed running outside and am gladly trading in my TV watching for the sunshine and running tights.