Hi! I'm a kind of unfit lady who is in week three of the couch to 5 k, and loving it so far! I've never really been athletic, and I am about 30 lbs overweight. I recently started wearing a heart rate monitor during my runs, and I was shocked to see how high my heart rate goes when I am running. My resting HR is 65. Brisk walking brings it up to 140 or so. Running for three minutes this morning brought my heart rate up to 195! Before today I thought my max hr was 185. Guess not! While running is very challenging, I can sort of keep up a conversation while running (with some gasping towards the end of the interval) and my legs don't feel too tired. What's the deal? Should I slow down? I'm already running very slowly. On the treadmill I walk 3.5 mph and jog 5.8 mph.
So, my question is this: Will my heart adapt to this new strain I'm putting on it and become more efficient so I can run at a lower heart rate, or am I putting undue stress on it by going up to 100% of my max heart rate, sabotaging my fitness goals and opening myself up for injuries? Thoughts?
Speed is relative - I think 5.8 is pretty fast on the treadmill - esp. for a beginner runner. You may want to slow that down and see what happens to your hr. Also, you aren't running at 100% of your max hir - it is most likey higher than you think. When I first started wearing my hr monitor I got very freaked out by the hr's in the 180's that I saw. I asked my doc about it and she asked lots of questions about how I was feeling - any chest pain? - no, any dizziness? - no, feel nauseaus? - no. Anyway, you get the picture. I did find though that if I kept my hr up that high for my long runs (over 4-5 miles), I would be exhausted for the rest of the day. Your best bet would be to see your doctor and get their advice. A little trick to find out your max hr is to find a hill (or set the treadmill on 4-5 incline after you have warmed up) and run it for 1-2 minutes. You should get close to your max hr doing this - but you don't want to do it without a clearance from your doc first! Then, try to keep your hr at 60-70% of your max during your runs. You will know when you hit your max - you will be struggling to catch your breath and you won't be able to maintain it for more than a few minutes. Doesn't sound like you are there yet in your 3 min. runs. Also, as you get more fit, your hr should settle down. Mine still gets up there when I do speedwork, but it stays in the 120's when I do a brisk walk and the 150's on my "easy" runs.
Hope this helps.