Is there a formula for water resistance?

A friend of mine has suggested that I try running in a pool to help get in shape. He says that since it’s harder than running on land, it will be better exercise. Any truth to this? Is there a way to measure it, if true?

As far as general cardio fitness is concerned, heart rate is what matters. How you get there is your choice. Water running is terrific for maintaining fitness if injured but it’s not superior.

The resistance is ‘drag’. The drag force exerted by a flowing fluid on a body is a function of the density, viscosity and velocity of the fluid. If the body is moving then the water is pushing back with this drag.

But runnerpat has the practical answer.

Asa mentioned above the great advantage is those with knee or hip problems. I can not run on hard ground for very long. But I could in water so for me water running would be better exersize. Land running for me is a fast walk.