I get this question all the time. The answer is, well it depends. Some of the main factors to consider are age, experience, and fitness level.
Age: The older we get the smarter we need to be in the way we train. You can get away with almost anything when you're 23, if you hurt yourself, you’ll probably be better by the next day. When you're 43 a small tweak is going to take weeks, maybe months to completely go away. I hurt my thumb a couple months ago, the doctor said it should be better in 9 to 12 months. WHAT?!? If this happened 20 years ago, first I probably would’ve never hurt my thumb to begin with, and I’m pretty sure it would’ve healed much faster. So we need to be smart, that doesn’t mean we don’t push ourselves, we just need to be selective on how often and how hard. A good phrase for the older athlete to have in their head is “that’s good enough” Chasing deadlift PR’s are fun but is the risk really worth the reward? If I hit a PR now, I’m still not really ever truly at 100% effort, so if I hit a PR lift (which I still do) I am operating no more than 90% of my effort. I feel when I go over that, I’m taking an unneeded risk.
Experience: It takes some time to know your body and how to train the right way with the right intensity. If you come into the gym and haven’t worked out since high school and expect to pick up where you left off, you know how well that’s going to go. So to build a good base, start by just focusing on consistency, no other expectations. For someone who is new or it’s been a while, it’s best to intentionally hold back. Just check the box. For how long? Once your body gets used to the movements you’ll get stronger and more comfortable, at that point, you can start picking up the pace and adding weight. Don’t rush it, be ok with just showing up and trusting the process. You don’t want to get injured or overwhelm your body out of the gate.
Fitness Level: This is pretty much the same as experience, the difference might be a young guy who is active and generally fit, but with little experience in the gym. For him we can ensure proper technique and give him the green light to push a little. On the other hand we might have someone who thinks they have a high fitness level, and years of “experience” but they were following different training methodology. For example, maybe they have been doing a bodybuilding style program for 10 years, so they have some experience doing curls and calf raises, but they probably haven’t run or done a pullup in that time. So it depends, we really want to avoid pushing too hard too often when we don’t have the appropriate fitness level. The body just isn’t going to respond well, get the fitness level up, then push as you are able.
The other side of this argument, is you might be being too careful. For example we do this exercise at the gym we call Jane Fonda’s: basically just side leg raises for a few minutes, they burn, they really burn actually. The thing is though, nobody is going to get injured from them, it’s just uncomfortable, and good things are happening in that discomfort and burn. So it takes a little discernment to gauge a movement or exercise and decide if this has the potential for injury. If the answer is no, or very low risk, then give yourself the green light and put some extra effort into it. I am always cautious with heavy lifting, but if I’m holding back just because it’s a little uncomfortable, I can’t let myself off the hook that easily.
So take it slow, get some experience, push when safe to do so, and BE CONSISTENT.