More reps with less weight doesn’t mean you’ll gain or retain muscle During covid lockdowns I was limited to a pair of 20kg dumbbells I was dumbbell bench pressing that for like 50 rep sets During that time my bodyfat stayed the same, but my scale weight actually dropped by about 20 pounds over 8 months of no gym, let me repeat myself… bodyfat stayed the same….but my scale weight fell by 20lbs… I lost 20lb of lean mass during that 8 months or so period of no gym besides dumbbells at home Now it’s been like 2 years since I’ve been back at the gym and I’m back to dumbbell bench pressing 50kg dumbbells for 8-12 reps and I’ve retained that 20lbs of lost lean mass 50kg for 12 is 600kg workload tonnage for a set20kg for 50 is 1000kg workload tonnage for the set The 1000kg tonnage was incapable of retaining my lean mass This proves without a reasonable doubt that you have to actually be lifting heavy weights to gain and retain muscle, you can’t go log by and increase reps / tonnageYou could say I lost size overall because I had no gym access for 8 months and it wasn’t just chest, shoulder and tricep mass that went down, yes that’s true, but the point is all those muscles reduced in size too despite me still giving them loads of tonnage
By the way that calculation is for each arm, not totalAt home dumbbells bench with 20kg in each hand for sets for 50 reps = 2000kg tonnage At gym dumbbell bench with 50kg in each hand for sets of 12 = 1200kg tonnage Was not able to retain the muscle mass dumbell bench press at home with such a light weight compared to my gym weights despite doing way more reps and tonnage
