Would it not be smarter to start lower like 140kg give me a run up. Also would you suggest that I just do my normal workouit as usual after? Also what is teh function of stretching?
re the plates: nah 20kg is a round number - 44lbs 45lbs is also a round number, just ahppens to be 20.4kg.
10kg =22lbs 15=33 20=44 25=55
Do your normal warming up first maybe, bar 12reps - 60kg 4-6reps - 100kg 4-6 reps (and maybe 2 reps with 120kg if necessary)
then 4 worksets with the max amount of weight you can handle and still be able to do 4 reps. if your max 4 rep is 150kg there is no point in starting with 140 if 4 reps is "easy" with that weight.
And you definitely will NOT be able to do your normal workout after, you exchange your normal pressing exercises for this.
Stretching is very important, especially with such heavy weights and huge loads (4 reps) it will make your chest stronger/better too, kinda hard to explain how.