Physiologically speaking, is lifting 100lbs the same as lifting 20lbs 5 times?
Is one more stressful on muscles than another.
If I wanted to get Brock Lesnar huge, should I dead lift a car or curl bags of groceries a million times?
Shit load of steroids. (only semi-
)
For mass, more weight and fewer reps, generally in the 6-10 rep range.
Heavy weights / low reps for size, high-reps, lower weights for definition.
You need low body fat for definition, and you won’t necessarily get that from low rep weight lifting alone.
You get that from surgery.
or, OR, cardio. Whichever.
Heavy weights and low repetitions develop fast-twitch muscles for shorter bursts of power.
Lighter weights and high repetitions develop slow-twitch muscles for longer endurance.
Compare the bodies of a sprinter and a marathon runner to see the difference on body shape the development of these two different muscle fibers produces. If you want visibly big muscles then go for heavy weights and low repetitions.
You can bulk up even if you’re mostly slow twitch. Slow twitch won’t get quite as big as fast twitch but it’s not hopeless.
The reason distance runners are so skinny is that heavy aerobic work burns some muscle tissue and it’s not conserved/replaced by diet and lifting
Also moving away from muscle twitch arrangement, my personal experience is there is not a linear response in strength, though I can’t explain why exactly. A good comparison exercise is the squat as it is easily repeatable and uses a significant portion of the body. When I was weightlifting, as an example, i could squat 60kg’s 40-50 times, 100 kg’s 15-20 times, 150kg’s 3 times and 180kg’s 1 time only. These all represented maximum efforts on my part. So definitely not a linear response and if you wanted to improve in the top end (max amount squatted) you would have to focus on lifting in a similar manner i.e. low rep / max weight training as other have suggested and you would logically conclude.
From a physics point of view, i would guess the work done / energy expended in each situation is the same, ignoring the efficieny of the human body being superior in either lifting regime?
At low weights, endurance capacity comes into play.
There’s also the factor that muscle fiber recruitment, even at near max weights, is only a fraction of the total available.