Reader submission:
"What is the best type of exercise to get a low heart rate"
The idea being that cardio-respiratory fitness, basically how well your heart and lungs are working, goes along with a lower resting heart rate as we can see marathon runners and sprinters with resting heart rates in the 40's or 50's. It's also more recently been shown to have some beneficial long term effects on brain volume as people get older, which sounds like a good thing, unless you have a small head. Fun fact: For UFC fight clearance, they make us check people's heart rates before and after doing 100 jumps - it doesn't change much from what I've seen.There's a lot of different opinions out there, so instead of doing a lot of reading, I walked into the middle of our cardiology office and just asked the question loudly and the answers I got boiled down to either long-distance running or high-intensity interval training. I'm assuming that you can also lump in any long distance activity with a higher heart rate along with running such as cycling, swimming, those weird road-elliptical machines but I'm not sure if you can count hiking and walking depending more on how rigorous they are.
Similarly, along with high intensity interval training (short bursts of high energy), I think you could lump sports that include high intensity bursts for 10-20 seconds at a time.
Your heart being like any other muscle, both of these forms of exercise work it out and help it get more efficient at recruiting muscle to do the work. I think it's worthwhile to consider the other option if you've only been looking at one of these before.
If you're looking for some fun tips on interval training from the fancy-pants at Harvard, here you go!