The One Workout Mistake Most Guys Make in Their 30s and Pay For in Their 40s, According to a Veteran Trainer

Though you may have noticed some new aches and odd sensations in your late 20s, your 30s are when years of life’s wear-and-tear really start to catch up. And though you may still feel physically strong enough to lift the familiar heavy weights of your youth, there are now other factors to consider: recovery, stress, sleep, and overall load of life. By their 30s, many men begin making the mistake of doing too much, too soon.

"Your 30s are not about ego lifting," says Kris Herbert, founder, trainer, and creator of The Gym Venice. "They are about building a foundation. If you survive your 20s, you build in your 30s so you can flourish in your 40s and beyond. Most men try to swing for the fences before they have earned the right to step up to the plate. Mastery beats intensity every time."

Muscle may adapt quickly, but tendons aren't as quick to catch up. When tendons are the weak link, they eventually fail, which ultimately leads to injuries. Either you build tendon strength deliberately over time, or risk injury and be forced into rebuilding it.

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We’ve all been guilty of heading into the gym and getting caught up in silent lifting competitions with the other lifters around us. But Herbert emphasizes the importance of slowing down and owning the fundamentals.

"Focus on controlled reps, clean mechanics, and performing compound movements well," he adds. "Build capacity before you chase intensity. Consistency over years will always outperform intensity for weeks. The men who stay strong long term are the ones who respect the process early."

If you’re worried you’ve been pushing too hard, listen to your body. It provides feedback long before it breaks down if you listen. Lingering pain, tightness that won’t improve, or a joint that feels unstable are all warning signs. Herbert follows a simple two-week rule: if something isn’t clearly improving after two weeks, it’s time to address it with bodywork, physical therapy, or targeted recovery.

"Pain ignored becomes injury, which slows progress," he says. "Strength in your 30s is not about proving how strong you are, it's about building the body you plan to live in for the next 40 years."

Related: The Smarter Way to Build Strength After 50 (Without Heavy Deadlifts)