I used to exercise a lot. I used to have great strength. I can do 40 push-ups in a row, but it's hard to do 30 now. I had a rest, too. It's no use resting for three days.
Strictly speaking, the number and speed of push-ups can't explain the quality and effect. Under the condition of ensuring the posture standard, the higher the slow speed, the higher the quality. In addition, the effect also depends on the posture, which determines the strength of the arm's endurance. All actions about fitness are not determined by quantity and speed. Therefore, frequency and speed are not the criteria for push-ups. If you can do four groups of 80 high-strength and high-standard push-ups, this effect is much better than doing 40 push-ups per minute without completing the second group.