Topping out?


I bike on a trainer and do intervals. This morning I noticed that 40 secs after I did a really hard 45+ sec intervals my hr went from @130 to @158 and stayed there for @30 seconds before dropping back down. I let my hr drop down below 120 in between intervals, fwiw.

Anyway, I'm 74 and have two questions--Anyone else have this sort of delayed response? (I thought my device was set for a 15 sec response) and Am I endangering myself for questionable results?

I'm not wanting to win any races. My goal is to be around for my grandchildren's HS graduations. :-)


Don in WI


Rate Response

by AgentX86 - 2021-11-05 18:45:32

What you write is a little confusing.  You say you went from 138-150 and stayed there for 30 seconds before dropping back.  Were you still exercising?  Or are you talking about your plateau time after stopping.  If it's the former, perhaps you're hitting you max tracking rate.  If the latter, you probably do have it set for 30 seconds.  Your rising dwell may be 15sec, as you remember.  Do you have your settings?

At 74, you're already exceeding the maximum heart rate suggested by the AHA (150).  The max most doctors want to see is 90% of max, or in your case 135.  I'm surprised that your EP allows your heart rate that high.  The top end of my PM is 130MPH.


The delayed response that you're seeing is quite common

by crustyg - 2021-11-06 05:24:20

When you say that your device is set for 15s response, that doesn't mean that it will achieve *all* of the rate response adjustment in 15s!

Just as with any other muscle, it takes some time for the normal heart to increase its rate - even a fit youngster won't go from 60BPM to 120BPM in 10s.  When your body goes into fight-or-flight mode the first thing to change is the intensity or strength of each heartbeat, not the rate.  Remember how your coach would always remind you to warm up before serious excercise?

The PM vendors try to achieve the impossible - keep your HR at a sensible rate for what you need (as judged by movement, and perhaps by measuring breathing) and transition you smoothly from a sensible HR when sedentary to what you need for climbing stairs, running for a bus (remember that?) or formal exercise.

FWIW, I see this all the time: come up stairs two-at-a-time and about 20s later my HR reaches maximum, long after it's needed!  I hope to be allowed a maxHR of at least 150BPM in ten years time.

What would be a sensible maxHR for you? Difficult to be sure, but if your coronary arteries are clean and healthy and your heart muscle is undamaged, then a maxHR of 150BPM might still be entirely appropriate: no one really *knows* what it should be and it's very individual.  If you don't have heart-muscle pain at 158BPM then you're probably OK.

Or you could ask your EP-doc to schedule a Bruce protocol session on a treadmill (benefit being that your ECG may show something wrong well before you get chest pain).

Hope that helps.

Delayed response

by Skeet - 2021-11-06 15:51:50

I wish my PM responded that well. I'd take that any day.


Exercise, heart rate, pacemaker settings

by Selwyn - 2021-11-07 08:06:54

Both the onset and offset heart rate response times to exercise can be programmed for your PM. 

Should you reach the maximum heart rate as set by your PM, then if you have some heart conduction you can exceed that rate if pushing yourself in exercise. This is intrinsic to you, not your PM.

There are different calculations of what is the maximum heart rate in exercise for age etc. (see   for examples).

Unless you are used to exceeding your maximum heart rate, I would suggest you go at things gradually and build up. Sudden death is associated with overdoing exercise. A few years ago ( 2017) recommendations were  moderate intensity exercise for 30 minutes most days of the week for a total of 150 minutes/week, or vigorous exercise for 75 minutes per week, spread out over at least 3 sessions per week. I have heard it said that 20 minutes of exercise per day is sufficient to keep the cardiovascular disease at bay. Exercise also reduces some cancers ( eg. bowel).

The race to be won is survival. In general, too much of anything is bad for you... sadly!



Maximum Heart Rate

by IAN MC - 2021-11-07 08:51:08

Thanks for the reference,  Selwyn .....very interesting !

One thing which is evident is that you can't possibly predict the maximum HR of all individuals using a single formula.  There are probably charts on gym walls all around the world which are based solely on "220 minus your age" ..... a formula which has very little scientific basis !  We are all different with different levels of fitness, different heart conditions, different drug regimes etc.

I read somewhere that the majority of Max HR formulas tend to over-estimate the max HR for younger exercisers and under-estimate it for older ones.

Instead of trying to work out an individual number , we should never under-estimate the importance of listening to your body. If you are breathing heavily but can just about hold a conversation,  chances are that you are in a safe training zone I.M.H.O.

I got my PM in my seventies and had a hell of a job persuading them to raise my maximum tracking-rate from the out-of-the--box setting of 130 bpm. After lengthy treadmill sessions using the Bruce Protocol I eventually got it raised to my current level of 165 bpm.   I am now 82 , and still with a max of 165 ......but we are all different !!


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