The talk test is a one of the easiest ways to monitor your exercise
intensity. You don't need any equipment, like a heart rate monitor.
All you really need is the ability to talk and breathe.
Whether you can do both at the same time is where your intensity comes in.
push ups and jogging/running
pushups benefit physical strength and jogging/running benefits aerobic capacity
External or internal and an example is how you feel about yourself I think
