Why is my heart rate different with different activities?

There's a standard of variables that can throw off your heart rate: how FIT we are, how HOT it is, and how much STRESS we are under (lack of sleep can also impact)

For example, with running our "load bearing" is greater and requires more work to overcome gravity

With cycling, we have the mechanical assistance of the bike, this produces an overall lower max heart rate

In swimming, which is "zero impact" we also typically produce a lower heart rate because the water keeps us cool

Strength training works our heart in a different way. As muscles contract - say during a bicep curl --they press and and close the blood vessels that flow through them

This leads to an increase in blood pressure in the rest of the body and the heart rate has to fight against a stronger force to push blood out

Cardio based exercise improves the NUMBER of new blood vessels while resistance training increases the SIZE of those blood vessels

Think of strength training as an entree and cardio as your side dish. PS: This doesn’t mean I don’t like cardio. It means a steak alone is not a good dinner. The veggies are important too!

Whatever your goals are, strength training has a place in your routine