Okay, you shamed me into doing it :)

So, this is really rough napkin math, but here goes:

Assuming that...

... a sedentary person (Donald) has a resting BPM of 80.

... an active runner (Justin) has a resting BPM of 60, and a peak BPM of 180 (while running)

If Justin runs for a solid 2 hours, five times a week, he will have

    158*60*60 + 10*60*180 = 676,800 beats per week

While Donald, who doesn't run, but averages 1 hour a week doing strenuous activity, will have

    167*60*80 + 1*60*180 = 812,400 beats per week 

Donald's heart beats 20% more often than Justin's. (And that's assuming Donald's heart also peaks at 180.)

(Edited to change names and fix math errors)

Just to be that guy: using two names very similar to eachother (especially for a non-native speaker) is very confusing for examples like this.

Thanks. I actually confused myself when I was writing it. I should have taken that as a sign to change the names. (I was going for a reference[1], but that shouldn't muddle things!)

I hope the new names are differentiated enough.

[1] https://en.wikipedia.org/wiki/Dan_%26_Dave

Thanks for doing the math. I’d say 130-140 would be better than 180 for someone in shape.

Most people can’t even hit 180 after their 20s.

No wonder I dread going to the gym, I find it really strenuous. I'm 37, unfit, and try to hit 180 while running on a treadmill. I was using the same target BPM that I used in college.

Thanks! I'll try 160 BPM next time. Running 45 mins should be more doable.

It depends on your goals. If you just want to do the 5K as fast as possible, you'll be close to your max heart rate (180). If you're just "leisure" running (aka. you can talk while running) I suppose 140 is reasonable.