Cardio at a high heart rate

[konkapot]

I have recently started running in an effort to run my first 5K (couch to 5K program from coolrunning.com). I was not a couch potatoe before I started the program - and was already doing 4 to 5 hours cardio a week.

My question is this:
When I do the running segments of this program (I'm on week 4), my HR gets way up there (I'm 39, my estimated max HR by the charts is 181). Usually by the end of the running segment, my HR is up to 168 - so OVER 90%.

I'm not worried that I am in the "anaerobic zone" and not burning fat - I'm doing this to build my running endurance not burn fat. (I spend an additional 30 to 45 minutes in a "fat burning zone" after I have completed the couch to 5K workout for that day to make sure I am still getting the "aerobic" benefit of my cardio)

What I am worried about: how dangerous is this? And if it is dangerous and I need to build up my cardiac capacity so that I can do the running without my HR going this high, what's the best way to do that -I am assuming you do this with cardio - but then should I be doing it at the higher end of a safe heart rate?

Looking to hear from informed people.

Thanks,
Maggie

[jwsarge23]

Maggie,

I'm not a running pro by any means, but I have run (sorry, not a play on words) into the same issues. I was/am a cyclist and wanted to add running for wet/cold days and to do some triathlons, running kicks my butt. I couldn't go at all to begin, HR shot up and stayed, felt like I was dying. Your body will adapt quickly.

It sounds like you are separating the 2 different goals - run a fast 5K and burn fat. You will still burn some fat at a high heart rate , unless you exceed your ventilatory threshold and then you will still get some afterburn, but this is not the main focus of a workout adding speed.

Danger - assuming your maxHR is correct (some other methods to estimate http://www.brianmac.co.uk/maxhr.htm, I personally always suggest cardiac stress test), 90% is pushing it pretty hard. My maxHR is from personally monitored tests (read: stupid) and my run max is 4 beats higher than the bike, more body parts flailing around. Sounds like your body/heart is capable of maintaining this, at least in short durations, and will adapt more to the higher load, but I would bring it down a notch or two for safety, you can't train if you're dead.

You want to train your body to go the same speed or faster at a lower HR. What has worked best for me is speed work, once you have some good base miles in. Strength all your running related tendons and muscles up with some good 75-80% work and then prepare for gains to come. Now, after your warm-up, hit that same 75% effort, hold steady for 3 minutes and then put some extra drive in that step and head for the 90% mark for a minute, rinse and repeat. What you are doing here is warning your body that future workouts are going to be at the 90% effort, but that you expect the 75% HR from it. Tossing some sprints in will also teach the body to go faster, turn the legs over quicker. The idea is to be able to link those hard efforts together on race day.

[jwsarge23]

Should have asked how far you are currently running and at what pace...

[konkapot]

I am trying to do this at a 5.5 mph pace - which I'm sure is slow to most, but is my "running for my life, the man with a chainsaw is chasing me" pace - I think it's because I have short legs . And I just started running after .... uhm .... 13 years of not running. And even 13 years ago I was slow (never faster than 6 mph) and never went very far (never more than 2 miles - that's why the goal now of a 5K).

I started this "couch to 5K" thing as a way to break through a weight loss plateau (I had lost 45 pounds and was stuck! Not stuck now, lost over 50 pounds with not much more to go).

I do kind of separate my "fat loss workouts" with the running workouts. The "couch to 5K" workouts only take about 30 minutes and only 3 times a week. I try to do at least 4 hours of cardio a week, if not 5. So on the days I do the running workouts, I add a bit more cardio (usually walking on the treadmill at an incline) to make sure I get the 4-5 hours of cardio a week I try for.

I have found some info that pretty much agrees with the points you brought up - first of all find your true max heart rate. Second - short bursts into the higher intensity helps build your cardiac capacity, increase your "lactic acid threshold" and also helps you train for sports that require short bursts of high intensity. I have also found several web sites that talk about training in the 90% zone, so just knowing that people do it makes me feel better.

Your description of running: "kicks my butt", "HR shoots up and stays", "feels like I'm dying"..... right there with you. I'm in the medical profession and I keep meaning to ask the doctors I work with about all this - see what they have to say. We'll see. But in the meantime, I feel a little better about it and I think I will slow it down a little .... although much slower and it might be considered a fast walk!

Thanks for the feedback!

[konkapot]

Found more answers - from a marathon running sports doctor.

Training at 90% of max HR is not going to damage your heart.
Your max HR is theoretically the fastest your heart will beat at all out max effort - so if your body can take you there, your heart will keep up until your body can't anymore. In other words, your body will stop you before your heart does. And training in this "anaerobic" heart rate zone, also referred to as "speed work" is actually important in improving cardiovascular fitness and training your body/heart for those bursts of speed (which is pretty much what you suggested - go for a few minutes at 75 and add some sprints up to the 90%).

Again, thanks for the input!

Maggie

[jwsarge23]

See? I wasn't leading you astray.

[konkapot]

Nope - you did alright. Thanks!
When I ran today I just left the HR monitor at home .... it's funny that I didn't feel as tired during my workout. I think watching my HR rocket up sends a subliminal message that I'm exhausted. Maybe I should forget the HR monitor more often!
Thanks again,
Maggie