You should always be skeptical about one-size-fits-all clothing. The same can be said for fitness facts. Just because you like the way a particular person looks doesn’t mean following their diet or routine is going to give you the same results.

With that in mind, we remind you about five popular fitness beliefs and why you shouldn’t treat them as the truth and nothing but the truth.

1. The 80/20 rule is 100% effective
A trendy fitness plan these days is the 80/20 rule, meaning you follow a nutrition protocol such as the keto or carnivore diet 80 percent of the time and then basically eat what you want the other 20 percent.

Supposedly, that creates balance. Wrong.

What often happens is people hit that 20 percent time span and have a pizza, four beers and a bag of chips. Sorry, but there’s no way you haven’t undone everything you’ve followed during the 80 percent time frame.

The best use of the 80/20 rule works is if you follow it after you’ve achieved your fitness goal of weight loss or gain. At that point, it’ll be easier to maintain something that doesn’t feel like punishment. I’ve tried the carnivore diet to see how it is. While it’s effective, at times it is torture to follow and doesn’t provide enough balance or variety.

The best approach is having a nutrition plan that’s balanced for you. It’s about knowing what your body needs for fuel and what foods your body doesn’t react well to. Avoid those foods, eat well and you'll be fine.

2. Wearable devices are wonderful
Many gifts are unwrapped to reveal a fitness device that’s worn around the wrist and measures things such as steps and heart rate. The problem with these devices is accuracy – or the lack of. Most are relatively decent at tracking heart rate if you get a good quality one, but fall short in counting calories or steps.

For example, I was walking through a train the other day to get to another spot. When I looked at my monitoring watch, I’d supposedly taken 4,000 steps. In reality, I might have moved 100 steps. It was measuring the distance I travelled, not realizing I was walking on a fast-moving train. I thought, ‘Wow, that's an easy way to get to my goal.’

3. Compound exercises trump isolation exercises
Compound exercises have taken over what’s cool to do in the gym. Basically, they’ve kicked isolation exercises to the curb. But if you dismiss them, you’ll be losing a key ingredient for overall strength and fitness.

It’s true compound exercises should be the foundation of programming because they strengthen through big, multi-joint movements such as squats and deadlifts. What you have to remember, though, is that isolation exercises help weak muscles such as biceps and hamstrings that aren’t as impacted by compound exercises. If you strengthen those, you’ll look better and be stronger doing your compound movements.

Besides, isolation exercises are fun to do. You feel the burn and see the definition of specific muscles. They’re a great way to end your workout after you finish your compound exercises.

4. Low reps rule
If you do high reps, you might as well be doing cardio. That’s a prevailing theory in many gyms, with people believing low reps equal the most gain. Over time, that’s just not an accurate statement.

Yes, low reps give you great gains, but they can lead to injury and you’re going to plateau.

You need to utilize multiple sets and rep ranges for the various cycles and phases of your fitness program. If you do reps in the 10 to 12 or 15 to 20 range with lower weight, you’re going to burn fat so it helps you lean out and creates muscle endurance so you can lift more. Think of it as a way to progress.

5. No need for corrective exercises
There’s an attitude out there that if you just do your compound lifts, you won’t have to do corrective exercises because compound exercises are corrective in nature. Not true.

If your form isn’t great because you have something like poor ankle mobility, you could be in a poor-form pattern so all you’re doing is reinforcing that pattern and making your issues worse.

Talk to one of the pros at your gym so they can help you figure out what your issues are. You’d be surprised how many are out there, from limited hip mobility to rounded shoulders to knees that go in.

When you know what corrective exercises you need, key on one or two. Do some as part of your warmup and between sets. You’ll improve your compound lifts, prevent injuries and ultimately, get the results you need.

The most important part of any fitness plan is to do your research. The best program is one you’re going to enjoy enough that you’re going to do it. if you’re not doing it, it doesn’t matter what you believe.