@mainten84 I love this shit. Here's math.
So, growth is approximately equal anywhere between 5 reps left in the tank and failure. It's a little worse but still good up until about 10 reps away from failing. So, if you can bench 3x15 at 185 and no more, about a three-plate 1rm, you'd be getting approximately the same growth if you did 3x10 at 185, and would still be getting good growth if you only did 3x5 at 185. Alternatively, each extra rep is equivalent to about 2%-2.5% weight increase. So, that lower bound of 3x5 at 185 is equivalent to 3x15 at about 145. But here's the thing, you get equivalent hypertrophy whether you approach failure at 3 reps or 30 reps, and while it's a little worse, it's still productive up until you're doing sets of 50+. So, we can knock another 15-20% off the weight and say that 3x50 at 115 will give about the same results as 3x15 at 185. But we get the same results at 3x5, so we can drop another 20% or so, and say we would get almost the same results with 3x50 at 85-95. Dumbbells equate to barbells at about a 2/3rd ratio if you half rep and about a 1/2 ratio if you go full range and really sink in. So, if we take things to the extreme, the actual science says that bench pressing 3x50 with 20-25 lbs dumbbells would be approximately the same hypertrophy as 3x15 with 185. And some interesting research has shown that 1 set a week yields about 80% if the maximum achievable gains, so you might only have to do 1 set with those 20 pound dumbbells.
Pushups are equivalent to benching with 70% of your bodyweight, so that's 135 for a 200 pound guy. Light workouts are fine. Mike Mentzer was well informed for his time. We can learn a lot from the wave of HIIT guys; lift hard and recover harder. But that's about it, everything they say when it comes to specifics has been proven to be either bullshit or inefficient. Oh, story. The most popular clips of Arthur Jones cuts out just before he says, verbatim, that "if a man has a maximum squat of 405 pounds, he could do 100 reps with 385." No. No, he couldn't. They're very silly men. Lift hard, go to failure if you want to and are willing to take an extra day to recover. Most importantly though, if you can sleep more, please do. Not just for muscles. We're starting to see that like, sleep stops cancer cells. Sleep heals daily brain trauma. Super duper important if you can manage to sleep more.