Precision rifle shooting while relaxed is a bit different than shooting while physically stressed.
Stress shooting training is very important, because it allows you to test and develop your shooting skills under the different kind of stress you may encounter in real world shooting situations. Using physical exercise to increase HR is a good way to simulate the effect of combat stress.
In this video the shooter is training to achieve a consistent “combat accuracy” on a 8×11″ steel plate, placed at 80 yards, under fatigue and high heart rate (HR). This is achieved using a workout protocol named Every Minute On The Minute (EMOTM).