counting your heart rate is important to differentiate aerobic from anaerobic exercise.

timing helps to control fatigue and stay within recovery limits.

i think its important even for a beginner. the body loves a routine, and responds well to certain controls. but such controls require impartial adjustement for advancemente.

i jog 8 miles in a day. Listening to your body is very important. Overdoing your workout can do permanent damage to your body.

It's good to measure so you can track progress.

Fun fact but I watch movies or shows whilst on the treadmill. Sometimes I don't even keep track.

I do so many squats I cannot walk no more. It's my fault for living on the second floor. (There is an elevator)