I can still push my heart rate way up, 200 range easy enough. But I train for triathlon year around, swim 3-5 miles, cycle (indoor or out) 75 miles and run/elliptical 18 miles and two full weight workouts per week. Yesterday some road weenies flew by me and something about it ticked me off, so I passed them for about a mile or so and made them chase, good thing my turnoff came up
. But, it takes longer to recover and I cannot sustain the output of my earlier years, nor the peak HR of course either, I go anaerobic much quicker too. I take my resting HR once a week when I wake up, Monday morning, it is less than 40 BPM.