16 of the Most Pervasive Fitness Myths We Busted in 2021

Here at Lifehacker, we pride ourselves on telling you the real truth about health and fitness — and leaving the bullshit behind. Unfortunately, the fitness world is a bountiful source of confusion, half-truths, and occasional outright lies. So let’s look back on some of the times this year that we set the record straight, from the fact that most HIIT is a lie to the fact that most fitness challenges are a waste of time.

Sweating doesn’t mean you got a good workout

We associate sweat with working hard, but sweat only means that your body is hot and trying to cool down. That’s all, I promise. You can do a hard workout in cold weather without sweating, or you can sit around on a muggy afternoon and sweat buckets without moving a muscle. So please stop assuming sweat is a sign of a good workout.

There are no exercises to “never” do

According to various know-it-alls on the internet, you should “never” do behind-the-neck presses, crunches, squats, deadlifts, dips, adductor machines, or…well, pretty much every exercise in existence is on somebody’s no-no list. The truth is that there’s no such thing as an exercise that is inherently dangerous, unless you’re bench pressing live alligators or something.

Most “HIIT” is a lie

I’m sorry to say it, but those supposedly super-calorie-burning, super-efficient “HIIT” workouts are almost never genuine high-intensity interval training. They don’t burn any more calories than ordinary cardio, either, and they aren’t a good substitute for strength training. Read more here to get your bubble fully burst.

Cardio is not killing your gains

Here’s a myth that I’m convinced only sticks around because lifters hate doing cardio. “Oh but it will kill my gains,” you can say, and it’s like you have a get-out-of-cardio-free card. Too bad that the supposed “interference effect” is overblown, and for most of us, adding cardio will actually help us make more progress in the gym.

The weight stack is lying to you

This one isn’t a myth that people tell each other; it’s more a thing that’s easily misunderstood. Those little numbers on the sides of the weight stack in your favourite gym machine? They’re specific to that machine. A similar-looking machine in a gym across town might feel totally different at what looks like the same weight.

The sauna is not a replacement for exercise

Just as sweat is not an indicator of hard work, that little hot room that makes you sweat is not the same thing as a workout. A sauna may have some beneficial effects on your blood vessels, and you may find it relaxing, but it’s not exercise, and it’s not going to detox you or burn fat.

It’s ok to work the same muscle two days in a row

Strength-training programs often have you rest a muscle before training it again, which is a fine way to make sure you’re not getting too fatigued. But it’s not a commandment. You can work the same muscle two days in a row if you’re smart about it. Even if you’re not smart about it, your muscles aren’t going to, like, explode. You might just feel a little more sore or tired.

Most fitness challenges are a waste of time

I understand the appeal of fitness challenges, I truly do. A challenge is an exciting opportunity to find out what your body is truly capable of. But so many fitness challenges are wastes of time that glorify suffering without delivering any real results. You can do better.

You don’t need to stop masturbating to make progress in the gym

This myth should have died last time it was popular, in the 1800’s, but there are still people out there telling young men that masturbating will sap their vital energy. This is flat-Earth level made-up nonsense. We debunked this back in 2016, but enough people still believe it that earlier this year we updated our debunker for the modern age. Here’s hoping this myth doesn’t follow us into 2022.

Creatine isn’t a steroid and doesn’t ruin your kidneys

Creatine is one of the very, very few supplements that can actually make you a little bit stronger, although it’s nothing like a steroid or other illicit performance-enhancing drugs. It’s just a concentrated version of something that’s naturally found in our diet, and it delivers a tiny, but potentially worthwhile, boost in the gym.

No type of fitness is more “functional” than another

“Functional fitness” is such a vague buzzword it can mean anything these days. From “CrossFit with the serial numbers filed off” to “anything that helps me in everyday life,” we break down the ways the F-word is used here. Bottom line: every kind of fitness is functional.

Super-short workouts are not actually short

You know all those super-short workouts (including the newest, the four-second workout) that are supposedly super efficient? They take almost as long as a traditional workout when you include the warmup, cool-down, and recovery times. They’re also not necessarily as good for you as the hype would indicate, so check out our take on the pros and cons here.

Spot your own bullshit

Want to play the bullshit-spotting game yourself? We have a field guide here with all the red flags you’ll see when a magazine or website is trying to lie to you about fitness. If something “tones and tightens” or “torches calories,” you’re probably looking at some overhyped mountain climbers and air squats.

TikTok’s worst offenders

You can’t escape the myths if you go on TikTok either. (You know, TikTok, the place where everything is true and accurate and never sensationalised.) We catalogue the worst of the myths here, which are really just all the same old myths with catchier soundtracks.

Detoxes are still a waste of time

Going all the way back to January for this one: detoxes still don’t detox anything, and we know you know that. You want to lose weight, or you want to regain control over your daily routine, or you want to not have to think about what to make for dinner for a few weeks. Here’s a helpful guide to what to do instead of a detox when you start feeling that way.

I make mistakes, too

Shocking, right? While I have the benefit of many years’ experience, and it’s literally my job to learn and understand new things about fitness, I’ve made my share of mistakes at the gym. My list includes “only doing cardio” and “never doing cardio,” if you want a sense of my range.