Resolved question:
Hi there. I'm 34, a few extra pounds, and I've really been working out to improve my health and hopefully lose some weight (for over a year now consistently and sporadically before that). I'm using primarily an incline trainer (treadmill with higher incline capability) doing slow walks at high inclines and sometimes faster walks at lower inclines, and I had a question about heart rate.
I know the most common formula for max heart rate (MHR) is 220-(age of 34)=186 bpm, so I try to target my HR between 50% (93 bpm) and 85% (158 bpm) of that max. However, I'm working with Jillian Michaels programs to build endurance, and at this point they sometimes cause me to exceed the 158 number and approach 186 (100% of max). Generally, these are ~30 minute programs with less than a third of it above 85% and only a few minutes near the actual MHR.
For example, today I did a 30 minute program. I'd say ~20 minutes were at or below 158 bpm. But for that other ~10 minute period, I was over 158, generally in the 160's/170's. I didn't get into the 180's today, but it does happen sometimes. I feel absolutely fine (like I'm working hard of course, but good) during this time. I even tested myself by saying a paragraph out loud (the talk test) while I was over 85%, and it was relatively easy to do (maybe a tiny bit winded but nothing extreme). If I wasn't wearing a heart rate monitor, I would just be thinking I was getting a good workout - there were no alarming sensations or anything.
I can do easier programs where I don't go over 158, but it just feels a little too easy and like I'm not making progress. I'm trying to get in better shape, and I feel like the programs I'm on that raise my HR above my 50-85% range are actually a bit challenging and I feel more accomplished when finished.
I also suspect, since MHR varies, mine might actually be higher than the 186 bpm estimate (I've also *very* briefly exceeded it before), but I've always been a bit too scared to try to find my absolute max by working at my limit (as my dad died of a heart attack after exercising in his early 50's).
I've read two schools of thought. One is that, unless you have a specific cardiac condition, heart rate monitors are overrated and you should go by how you feel, not your heart rate, when exercising. But I've read other things that say you should never go above 85% of MHR or you risk overtraining, reducing your heart's ability to recover after a workout, possible arrhythmia, and musculoskeletal injury. I just don't know what to believe.
So my core question is, is it safe for me to be pushing myself with these workouts (up to the MHR of 186 bpm) since I feel good? Or should I do the easier workouts even though it feels like I'm not getting as good of a workout as I could.
Thanks for any help/guidance you can provide in the complicated and confusing issue!
Submitted:
4 Days
Category:
Cardiologist
Thank you for your query at doctorspring.com Regards
As you yourself acknowledge this a complicated issue and there cannot be a 100 accurate answer. However I shall give you my opinion. The aim of your exercise is to burn your calories to reduce your weight. Exercising at slightly lower strain levels for slightly longer time will have the same calorie burning effect as doing heavy strenuous exercises for shorter duration. So to loose weight you may do less than maximum limit exercises for slightly greater duration and still achieve weight loss.
As far as cardiac health is concerned you are doing well if you routinely achieve the 85 percent mark without any problems. So you achieve adequate aerobic exercises even at 85 percent. The 220 minus agw formula is a generalisation and people may differ. You may nave a slightly higher heart rate limit. It is not extremely dangerous to cross the limit of 100 percent if you dont have heart diseases either coronary or structural heart disease. However it is still advisable to keep below the 100 percent mark even though it is not extremely dangerous given that you can tolerate it occasionally. This is because it is extremely safe below the 85 percent limit, reasonably safe below the 100 percent limit and a chance of risk above the 100 percent limit. Why take this chance when there is no major extra advantage than the less strenuous exercise done for a longer time.
Since you indulge in such strenuous exercises and you have had a family history of exercise related death you should also get a 2d echo to rule out structural heart diseases
Dr Vivek Mahajan
DM Cardiology
Hi, and thanks for your reply!
I understand your point about lower intensity exercise for longer. I do try to work in some lower intensity exercise during the week - for example taking walks around the neighborhood, etc. I also make sure I don't do high intensity exercise every day so I have break days for recovery.
I actually recently had an echo, and all came back normal. =) So I'm covered there - heart looked good! (My dad also had symptoms that I don't; for example, he had a tendency of fainting often, but apparently nobody ever caught he had a problem).
So in your opinion, if I keep going, but use the 100% MHR (186 bpm) as my maximum limit (ie. if I hit it, I'll ease up), that should be reasonably safe? That way I could push myself a little, but still have a limit I don't exceed.
Thanks again!
Hello. Yes. You could exercise upto a 100 percent limit for slightly longer. Nothing wrong in exercising above 100 percent specially since you tolerate it well, but why test the limits and take that small risk?! The heart rate values are based on general population estimates and limits maybe different for you than the population but then again it is better not to test the limit when you can gain the same benefits by exercising slower for longer time. Regards,
Good to know that your ECHO is normal.
Dr Vivek Mahajan.
Thank you. I'll make sure not to exceed 100% and try to aim for below that, with the majority falling below 85%. Thanks so much for the info!