I'm going to answer your question a little sideways because I think it's important to describe what the point of a warmup is, how it is used, and the conditions that require it to be taken more seriously.
I try to focus on a few things when it comes to weight lifting warmups, and break my warmup into two parts. This would be the "I just got to the gym" stage:
- Overall body heat. I want to break a sweat no matter what I'm doing.
- I want to ensure that I'm specifically warming up the muscles that I'm about to use. It's a little silly to use a bicycle to warmup for bench pressing. It's better than nothing, but a big reason that people love rowing machines is because it's a fairly decent head-to-toe recruitment activity. It's also hard and uncomfortable, which is probably why most people don't do it.
The above is usually about 5 minutes, but I also try to walk to the gym so that I'm fairly warm just showing up.
Then I'll do a specific warmup. This is a bit more involved:
- Specifically targeting the muscle recruitment of the lift. If you're doing squats, do some overhead squats, Turkish get-ups, and lunges. Keep the weight really light.
- Focus on the muscles and force you want to recruit. For cleans, I find doing box jumps very handy because it gets you into the mode of exploding. For bench pressing, abs-glutes-stiff-as-a-board pushups are a nice way to ready your arms and chest. For deadlifts and squats, glute bridges can remind you what your glutes feel like and how to activate them.
- Start with an empty bar, and ramp the weights. I can squat 2x my bodyweight, and have never started with more than an empty bar. After that, it's still 45's on the side, and up and up it goes.
When you can lift heavy (especially past the intermediate stage), a little tweak can really screw you up. So if you're going to pull a muscle or have some problem, you really want to find it at a lower weight. And all that proper warming up puts your body and mind into the right environment for success.
I want to know how effective this is. I just want muscle hypertrophy
(more muscle mass), and I'm really interested in strength, stamina,
Just to be clear, these three concepts (hypertrophy, strength, and stamina) are related but have very different training patterns. You can hop around between all of them, but top strength athletes are always stronger than body builders (who are bigger) and they both will tire out way before an endurance athlete who has tremendous muscular stamina.
The warmup needs of endurance athletes (and hypertrophy seeking body builders) are not as severe in the weight room as what I've described above, because they are not constantly knocking on their 1RM-3RM range the way a strength athlete will.