Anyone who has ever spent any time with me in the gym has usually heard me say some combination of the following when it comes to reaching goals:
"Eat relative to your goals, and lift as heavy as possible with good technique."
Is this a gross oversimplification? Absolutely. But why is that a bad thing? Does simple mean less effective? I wouldn't argue that. Sometimes the simplest approach can lead to the greatest results. In terms of movement, the plank probably ranks somewhere around dead last in the gym. The object is to remain as still as humanly possible. But will anything else teach us to brace the torso more effectively? Will we get better activation with a crunch or a med ball slam? Probably not. More tension? Definitely not. Sometimes simplifying things is the best jumping-off point for someone starting their fitness journey. Master the simple. Then graduate to complex.
The second part of that sentiment is what I want to focus on. "Lift heavy with Good Technique." What does that mean? What is heavy? What is good technique? Fitness is fluid, it ebbs and flows day to day, through both strength and weakness. It is relative to the individual. It's rare that two individuals will have the same goals, caloric requirements, or strength profiles.
The best advice I can give is to practice the skill of examining how hard you are working. All of my clients operate on the RPE scale; that means Rate of Perceived Exertion. At the end of each set take inventory of how difficult that set was and how many reps you feel you had left in the tank at the end. If you feel that you had more than 3 or 4, think about adding weight. Or reps. Or throw a pause in there either at the beginning or end of the set. There are lots of ways to make movements more difficult, resulting in greater activation, recovery, and growth.
Good technique is much closer to a fingerprint than a blueprint. Are there cues with most exercises we should more or less always adhere to? Sure. But at the same time, we all have different mobilities and abilities. Stay within your safe ranges of motion and control your weight in both directions. A great example of this is the squat. Inevitably, we've all heard some form of "Ass to Grass or it doesn't count." This advice, when given generally, is as dumb as it is dangerous.
Are you a professional powerlifter, being judged on your squat depth? Then sure, hit the mark. Are you a dentist, just looking for stronger legs? We should probably think twice.
If we lack the hip, knee, or ankle mobility to squat deep safely, then it's implied that we will squat deep dangerously. Most of the time, lumbar flexion happens. That's when we run out of hip ROM and our pelvis tucks up under us and we flex the lumbar spine. Over time that will lead to lumbar shearing, which, even if you don't know what that means, sounds bad. Shallow the squat out until you get rid of the curvature in the spine, and work from there. There is zero shame in that. Being able to come back to the gym the next day because you didn't hurt yourself is cool.
Eat to your goals- lift heavy with good technique. Simple is better.