Am I burning muscle?

JALangston

I may have just freaked myself out a bit, and I want to know if my logic is sound or if I can calm down a bit.

I'm currently training for a half marathon and have been using Hal Higdon's novice training program. I'm 27 yo and weighed at 191.8# today. I've been training for a month now (but I'm only on week 1 of the program). Usually when I run, my HRM says I'm at 142-156 bpm (aerobic) for the first half, then 156-168 bpm (anaerobic) for the second half. I feel fine while running--just did 4 miles this morning and although it was the first time I've ever run 4 miles, I felt great at the time and feel great now. I also run early in the am: get up at 6:00 and run before breakfast (tho I find I feel best if I eat half and apple and drink some water beforehand). I also only run a 15 min mile (4mph) because 1) the last time I tried to push the time I ended up hurting my knee and having to stop for a month and 2) I'm increasing distance so fast I'm kind of scared of burning myself out in speed and having to stop and walk toward the end (most days I have to psych myself up to believing that a 4 mile run IS POSSIBLE for me to do that the last thing I want to is sabotage that) and 3) my HR gets so high toward the end I worry that increasing my speed will, in fact, cause me to feel uncomfortable and stop in the middle of it.

So this was what freaked me out. I was reading an ACE flyer on interval training the Y gave me when I signed up for a membership. This is what it said:

"The anaerobic system, on the other hand, draws energy from carbohydrates (in the form of glycogen) stored in the muscles for short bursts of activity such as sprinting, jumping, or lifting heavy objects. This system does not require oxygen, nor does it provide enough energy for more than the briefest of activities."

Soooo, First Question: "carbohydrates" in the anaerobic system isn't protein, isn't muscle mass, right? I'm not shooting myself in the foot here?

Second Question: how can the anaerobic system be only for 'the briefest of activities' yet my heart rate is in the anaerobic zone for 30 minutes at a time? I know we're talking two different muscle groups here, but can someone explain to me the difference?

Third Question: should I keep doing what I'm doing? Is it normal that my HR is doing what its doing at only a 4mph run (keep in mind, I'm pushing around almost 200#)? Should I try to slow down even more? I truly feel great after a run, but am I hurting my progress in the long run by having my HR over 152 for an extended period of time?

Thanks!

robin52077

running is aerobic, not anaerobic, so the things you quoted do not even apply.

You are doing steady state cardio, which is aerobic, NOT anaerobic activity, which is short very intense bursts.

Luthorcrow

No. There is a lot of none sense regarding heart rate. The only really issue if you are pushing too close to your maximum heart rate. It doesn't sound like that is case from your post. You should calculate what you 70%-80% range which I would bet you are within with what you are doing.

Checkout this URL: http://www.brianmac.co.uk/hrm1.htm

Also, remember as you do it for several weeks I guarantee you that your HR will come down as you body adapts and improves. Most of what you experiencing now is your body being shocked. As your brain adjusts to the demands you will see big change after about 2-3 weeks. That is about the time you will start to make actual real physiological changes.

Also even if you are getting into the 80%-90%, which again I doubt you are, you would need to run at that level for nearly 2 hours before you body would run out of enough glucose to be in danger of burning muscle. On top of that, as long as you are getting a post workout protein shake with a piece a fruit (or in the shake) just after you workout you will have no issues with muscle loss.

JALangston

Ok, so what you both are saying is that the anaerobic state for the heart and the anaerobic state for your (leg) muscles are two separate functions and that my HR running @80% isn't an indicator that my (leg) muscles are in an anaerobic state as well (and therefore aren't necessarily using glycogen).

Luthorcrow

No, I am saying that you would have to be exercising at 80%-90% of your maximum heart rate to be in the anaerobic zone. As a 27 year old 150-160 HR is probably no where near 80%-90%. Right now you are just getting a good sweat and unless you well outside the normal range (lower) you are hitting a good rate.

What I am also saying is that if you are at 80%-90% of MHR rate and are burning up the glucose in your muscles and producing lactic acid, you are still not burning up your muscles. The average person has about 2 hours of glucose in their muscles. At 4 miles you just are not running long enough to even be close to that limit.

I am also saying the purpose of the post workout protein drink in first 30 minutes after you workout will help prevent muscle loss etc.

Now, if this is a real concern from you, then you are on the wrong path because marathon running, as you increase distance and time will eventually eat muscle. It just a fact of the sport. It is the reason pro marathon running looks anorexic. If that is your goal then fine but eventually you will hit that wall.

If that is not something you want then you might consider looking at strength training. You will actually add some muscle, nothing extreme, and burn more fat than running ever will. You should checkout a book called "New Rules for Lifting for Women". A lot of people looking to loss weight think they have to run. If it is something enjoy then more power to you but don't buy into the hype if it is not something you want to do because running is not the best nor is it good for everyone.

JALangston

Ok, great! you have really good stuff here and I appreciate all the information. You've answered my questions: my HR is high(er) because I'm not used to the activity. It is normal. It is good. My HR will correct itself in time. Glucose is not muscle protein and if I tap that energy source it will not hurt my muscles. Continue to strength train (3x/wk!) and eat plenty of protein (not an issue for me t'all) to replace what may be used and stop psyching myself out. Easy to do when your learning something for the first time .

So, thank you so much for the information!