heart rate and calories burned
While it does depend on training to a limited extent, cycling is a non-weight bearing exercise and will almost always require less energy over the same amount of time and percentage of VO2 max. But this will also be negligible at any intensity of VO2 max.
But more importantly, doing both is better than doing either one exclusively. Variety is the spice of life and fitness. Mix it up and have fun. Doing what you love is never work. I get to learn and teach and make a living all at the same time. I am rich where it counts for me. I hope you all get to do the same.