We never warm up. Interestingly as an adult I have never stretched before physical exercise and I have never pulled a muscle. As a teenager we did and I sometimes pulled muscles. Young kids in the park do loads of running about, they never stretch and they never pull a muscle.
Additionally, the warm up is a bit pointless if you bat first.
We were in the semis of our T20 competition, it was due to start at 11.00am. The opposition got there at 9.30 they did a load of warm ups and fielding drills. We turned up at 10.45. Ok we lost but only by 4 runs and they were 2 divisions higher than us.
Warm ups, a pointless waste of energy.