Common health and fitness myths that need debunking

In the age of the internet, access to health, nutrition, and fitness advice has never been more than a few clicks away. However, you can't trust everything you read, whether it's influencers trying to make money on the latest health craze or an old wives' tale that's been taken a little too seriously; misinformation is everywhere online.

In the best-case scenario, trusting a fitness myth might lead to wasted time, but others can have longer-lasting, more serious side effects for your health and bank account.

That's why dispelling some of the more common health and fitness myths is a good place to start. Here are the ones I hear most often, and what the science says.

Common health and fitness myths

Detox diets 'cleanse' the body

Ever since the 1940s, when the 'Master Cleanse' hit the mainstream, modern detox diets have been presented as a 'quick fix' remedy or weight loss approach. However, they are a gimmick. The liver and kidneys detox the body naturally.

There is little to no scientific evidence that diets like juice and water-based cleanses remove toxins.

Any benefits of such cleanses can be put down to temporary calorie restriction and the elimination of many 'unhealthy' and ultra-processed foods, rather than detoxification.

Gluten free equals healthier

The only people who need to actively avoid gluten in daily life are those with celiac disease or a gluten sensitivity.

Giving up gluten unnecessarily can lead to side effects like vitamin, mineral, and fibre deficiencies.

If you think you may have an issue processing gluten, speak to your doctor or a registered dietitian.

You need to drink 8 glasses of water a day

It's a good idea to aim for 8 glasses of water a day if you often feel thirsty or know that you don't drink enough water, just like 10,000 steps a day is a good number to aim for if you don't exercise enough. However, everyone's ideal water intake is different depending on the other beverages they drink, lifestyle habits like exercise and daily routine, and climate.

Those who do high-intensity exercise or live in a hot climate will need to drink more than 8 glasses a day, which is why some health bodies (including The Institute of Medicine) recommend between one and three litres a day.

Doing crunches reduces stomach fat

You can do all the crunches, sit-ups, and dead bugs you like, but there's no guarantee they'll reduce stomach fat, as it's impossible to 'spot-reduce' fat. To lose excess stomach fat, you'd need to lose fat generally across the entire body.

When we exercise, the body burns fat from all parts, not just around the muscles being exercised.

Intense cardio is the best way to lose weight

Intense cardio like running or high-intensity interval training (HIIT) might seem like the best way to burn calories, as we tend to burn more in less time while doing them, but they won't be the best for everyone.

The calories burnt while doing these workouts are often less than our fitness trackers tell us, and the high intensity can lead to a bigger appetite, which can lead to overeating, for starters.

Secondly, and perhaps most importantly, if you don't enjoy intense cardio, then you're less likely to do it regularly - and consistency is key when it comes to exercising for weight loss or maintenance.

Strength training makes women 'bulky'

Testosterone is a key contributor to muscle mass, and most women won't have enough of this naturally to build significant amounts of muscle. That alone means resistance training or lifting weights isn't going to make us 'bulky' without other interventions.

Also, to build significant amounts of muscle, you have to be consuming more calories than you're burning, prioritise protein in your diet, and do high-volume, intense weight lifting, so it's very unlikely to happen just by lifting weights a few times a week.

You have to sweat during every workout

For many people, sweating equals a workout, but it's a myth that you need to sweat for exercise to be beneficial. Sweating is how our bodies cool down - if you're not overheating, you won't sweat as much, which means you could be walking, cycling, or even running and not break a sweat. That doesn't mean it's not a good workout.

The extent to which we sweat also depends on factors like hydration levels, the type of exercise, body mass, fitness level, and even genetics.

Better signs of a good workout are long-term changes, e.g. improved strength or stamina.

Fasting is a good idea for everyone

There are many benefits to fasting - for example, fasting overnight may help improve your gut health by giving your digestive system a 'break'. However, it's not for everyone, and it isn't required to lose weight, which is one of the common reasons why people choose to fast.

It's very much a matter of personal preference. For some, fasting may boost energy levels, while for others, it can lead to fatigue, lower energy levels, and moodiness.

According to the NHS, some people shouldn't fast at all. This includes those pregnant, breastfeeding, with diabetes (especially those on insulin), with a long-term medical condition, and those on medication that needs to be taken with food. Always consult a doctor before making changes to your diet.

Sleep doesn't impact fitness

Many people think that exercise is the only thing that affects fitness, but this is a myth. Sleep, nutrition, and stress all play a part as well. Sleep is especially important.

Without enough good-quality sleep, our bodies can't go through the process of muscle growth and repair, which makes us physically stronger and boosts endurance.

Sleep also influences our immune system, appetite regulation, and the way our bodies store food for fuel.

More exercise equals better fitness

More exercise doesn't always equal better fitness. While most experts will recommend exercising (whether that's strength training or cardio exercise) at least twice a week to see progress, there is such a thing as 'overtraining'.

Overtraining is when the body doesn't get enough time to recover between workouts. When we overtrain, our performance actually decreases, we are more prone to injury and have increased muscle soreness.

Running is bad for your knees

Running puts a lot of force through the knees, which some people say leads to injuries and conditions like osteoarthritis. However, this is a myth. Studies have shown that running recreationally and slowly building up the mileage can actually improve joint health and lower the risk of osteoarthritis.

The real causes of injury are often running too often as a beginner, not recovering adequately, and not complementing the activity with proper mobility and strength training.

Fresh food is always better than frozen

Frozen food has a bad reputation, and it's all down to a little misunderstanding. While it's not a good idea to have frozen ultra-processed foods like ready meals as part of your regular diet, there's nothing wrong with frozen foods like fruits and vegetables. In fact, they contain just as many nutrients - if not more - than the fresh varieties.

They are also available at all times of year and tend to be cheaper than the fresh alternatives.

Everyone should avoid dairy

Much like avoiding gluten, there's no need to avoid dairy unless you have an allergy or an intolerance. Dairy products like milk and cheese are rich in calcium, vitamin D, and protein, which contribute to creating stronger bones, muscles, joints, and a properly functioning immune system.

Cutting out or limiting dairy intake is a personal choice and not everyone needs to do it to be 'healthy'.

As always, check with your doctor if you're experiencing issues like bloating, cramps, acne, or high cholesterol and think dairy could be to blame.

Brown sugar is better than white sugar

It's a myth that brown sugar is 'healthier' or 'less bad' than white sugar. The only difference between the two is the colour, flavour, and a tiny amount of nutrients.

Brown sugar contains molasses. This is what gives the granules the richer colour and deeper flavour. It also has trace (i.e. very, very little) amounts of calcium, potassium, and iron.

All processed foods are bad

In recent years, processed foods have become a buzzword synonymous with 'unhealthy eating'. However, it's a myth that all processed foods are bad. Some examples of processed foods include canned fish (like sardines), plain yoghurt, wholegrain cereals, wholemeal bread, plant-based milk, and baked beans. Like everything else we eat, they can be part of a healthy, balanced diet.

Peanut butter is a good source of protein

Unfortunately, peanut butter is not a good source of protein. While nuts have rightfully earned their place on the list of high-protein foods, peanut butter has not.

It only contains about 3.5 to 4g of protein per spoonful on average, with most of the calories coming from fat rather than protein. For comparison, there's about 12g of protein in one egg.

Rest days are a 'break' from training

Rest days aren't just a 'rest' from your workout schedule - they are essential to the whole process.

It's important to have them as they help the body repair the tiny muscle tears that come from exercising with intensity, preventing overuse or overtraining that leads to injuries.

Rest days also help replenish the glycogen stores in the body, which are our main source of energy.

Red meat is always 'bad' for you

Red meat is another food that has a bad reputation without good reason. While it's important to have it as part of a balanced diet, it has its own set of benefits.

Red meat is rich in essential B vitamins (especially B12), protein, iron, and zinc, which are all essential for essential bodily processes, brain health, and immune function.

Salads are always low in calories

For those looking to lose or maintain their weight, salads are often a go-to choice for lunch. However, they are not always the low-calorie meal we think they are. Additions like olive oil, cheese, croutons, batter on fish or meat, and dressings can quickly increase the calorie count.

A higher-calorie meal isn't necessarily an 'unhealthy' one by any means. Many of the higher-calorie foods are rich in protein, which helps keep us fuller for longer and so less likely to snack between meals, but it's something to be aware of.

Everyone should eat breakfast every day

The saying goes that breakfast is the most important meal of the day, but that's not the case for everyone. Some people find that eating early in the morning makes them feel nauseous or tired, or doesn't fit in with their lifestyle and routine. If this is the case, it may be a better approach to eat later in the day.

If weight loss is the goal, then intermittent fasting can be beneficial for some people (but again, not everyone).

You have to 'alkalize' your body with certain foods

Much like detoxes, 'alkalizing' your body with particular foods is a health trend with very little scientific backing. The body 'alkalizes' for itself when it needs to, as the kidneys and lungs tightly regulate our pH levels.

Alkaline diets do have some benefits, but this is because they include fruits, vegetables, fibre, and other essential nutrients, rather than the 'alkaline' effect they have on the body.

Stretching prevents injury

It's important to maintain flexibility as we age, but flexibility alone won't stop exercise-related injuries. In fact, stretching while standing still (static stretching) can actually reduce blood flow and relax the muscles when we need them active.

It's a better idea to warm up on the move (dynamic stretching) as this helps with blood flow and helps warm up the muscles before exercise.

A plant-based diet is always healthier

A diet rich in fruits, vegetables, and whole foods is always a good idea, but a plant-based diet doesn't automatically equal a healthy one.

If the plant-based diet is based on ultra-processed foods or foods lacking good nutrients, then it's not healthier than one that includes meat, fish, and dairy products.

You have to do 10,000 steps a day

In the 1960s, a Japanese marketing campaign for pedometers promoted a manpo-kei (translation: 10,000 step meter), and so the idea of '10,000 steps' was born. There was very little research suggesting this specific number of steps had any more benefits than a few thousand fewer, and over the years, studies have proven it.

In fact, a recent study found that your age decides how many steps you should do for better health, and other research has found that as few as 4,000 steps can make a difference.

While 10,000 steps is a great goal to have, it's better to aim for a few thousand and work your way up than do none just because you can't reach this goal yet.

You should feel sore after every gym workout

It's a red flag if you feel sore after every single gym workout, especially if you're exercising with a personal trainer. Delayed onset muscle soreness (DOMS) is a sign that your body is adapting to a new level of intensity, which shouldn't be happening after every single workout.

If you do feel sore after every workout, it might be a sign that you're pushing too hard, too soon or are overtraining, and need to prioritise more rest in your routine.

You shouldn't eat late at night

While there are gut health benefits to fasting overnight, and eating late at night might make it harder for you to fall asleep, there's no real negative to a late-night meal - especially if you have a lifestyle that means you're not home earlier in the evening.

A late-night snack or meal might be the only way to get the nutrients you need, and the timing of it shouldn't mean you have to skip a meal.

You need supplements to be healthy

The supplement industry has boomed in recent years, and while there are benefits to many of them, most people won't need them to be healthy. Protein powder does positively impact muscle mass, and creatine may boost brain health, but you can get the benefits of both without these powders and pills via other means.

Supplements should be adding something to your diet rather than replacing something, which is why many experts advise looking at your lifestyle, diet, and exercise routine before taking supplements to 'fix' an issue.

Always speak to your doctor before taking any new supplements.

You can lose weight in one week

While many plans promote ways to lose weight in a week, it's actually not possible for most people. It takes time for the body to adjust to a new calorie intake and exercise routine, so any weight loss in the first few days is likely to be water weight, which will likely come back.

Slow and steady wins the race when it comes to losing weight. A longer-term calorie deficit and moderate exercise will win over cutting calories or doing intense exercise over just a few days, which will likely just lead to fatigue, inflammation, and low energy.

Machines are safer than other types of weights

If you're new to the gym, machine exercises can be a great place to start as they guide movements and mean you can drop any weights. However, if you don't know the proper set-up or movement for them, they can create unnatural movement patterns, which can lead to injury or discomfort.

It's a better idea to learn the proper form for the movement you're trying to do with lighter weights, so you can replicate it on the machine, if that's the equipment you want to use.

You have to eat healthily all the time to be 'healthy'

What's life without fun? Being healthy doesn't mean exclusively sticking to the healthiest diet, getting the perfect amount of sleep every night, or doing the 'perfect amount' of exercise every week. A little indulgence is a good idea every now and then; otherwise, it'll become something you crave.

Research shows we're more likely to binge when we restrict ourselves, so it's always a good idea to have the thing you want little and often (exceptions apply, of course).

You should cut carbohydrates to lose weight

In general, it's a myth that you need to cut out any food group for better health - unless your doctor has said otherwise.

To lose weight, you essentially need to eat fewer calories than you burn every day, regardless of where those calories come from. Many people think that you have to give up the calories in carbohydrates, but actually, choosing carbs rich in fibre can aid the process as they help you feel fuller for longer and contain essential nutrients.

Body Mass Index (BMI) is a reliable way to predict health

BMI is a number created from a person's height and weight to categorise them as underweight, normal, overweight, or obese, and it's used by health institutions all over the world.

However, it's not a reliable way to look at health when other factors aren't also considered. It's considered outdated today as it doesn't differentiate between fat and muscle when measuring weight, the distribution of that fat (e.g. fat around the middle is considered 'more dangerous' than fat elsewhere), and it was developed for a specific demographic only (white men), so it does not apply to everyone.