Fasting, Aerobics, and Weight Loss

GoreTex Experiance Tour - Dave MacLeod goes for a run! from Hot Aches Productions on Vimeo.

I just got back from an easy morning run. It was slow, almost plodding, ended with a short stretching session, and in total took about 45 minutes. I did it because I need to shed a few pounds quickly and it’s the oldest trick in the book when it comes to fine tuning your weight loss.

I was reminding of this “trick” yesterday when my friend Ben brought up Dave Macleod using this tactic to get ready for his hardest routes. We used to run this tactic in college for track. As for climbing, before the most successful road trip of my life I’d tweaked a finger and had to back off on my training. Without the ability to train for strength I aimed instead for lighter (a roundabout way of getting stronger in gravity sports) by starting 3-4 days per week with 2-10 miles of easy aerobic-paced running. I ended up going into that trip 8 pounds lighter than my average weight, which increased my performance far more than any strength training could have hoped to.

Running in the morning before you eat helps improve your body’s use of fat for energy or, as Macleod puts it, “normally if I run I do it after the overnight fast to get into fat oxidation quicker”. A fasted state, while not optimal for hard training because you quickly run out of stored glycogen (or bonk, a point where your workout goes south quickly), is great for easy to moderate exercise because you can improve your body’s ability to tap into it’s “fat for fuel” process.

In general, light aerobic training has very little effect on your metabolic process. This is why you often hear trainers say things like “cardio only burns calories while you’re doing it where weight training burns calories all day long” and so forth. Aerobic training in a fasted state helps your training in two ways. It heightens your metabolism for a longer period of time than it normally would and it doesn’t break down much muscle tissue so you can utilize it during your hard training.

This is why when we recommend doubles programs one of your two workouts is always easier than the other. It’s not running that’s the magic pill here but aerobic training done in a fasted state. Running is efficient, since even easy running stresses the body more than most things, but any low-intensity exercise that raises your heart rate will work. For example, Cardio X was designed as the P90X doubles workout, which is why it’s much easier than everything else. If I don’t feel like going out, like I do right now because it’s raining so thankfully i'm already done, I’ll pop in a cardio vid instead.

vid: macleod on a 'run'. my runs are often similar. i don't generally (ever) solo 7B in my hiking boots but would guess well over half my runs are explorations that include a lot of off-trail rummaging around looking for rock, or whatever, which often includes technical climbing or, at least, scrambling over rock. you don't need to keep your heart rate at a steady state to get the effects of aerobic training. you just need to keep moving.