More Exercise Myths Busted

A man lifting weight sin gym with a personal trainer

In this months blog, our personal trainer, Lewis looks into 10 more health and fitness myths that we’ve all heard and separates the fact from fiction.

These are some of the exercise and fitness myths that I hear regularly, and it is impossible to do the research justice to debunk these myths in such a short paragraph, but I’ll try!

These are my opinions on current scientific evidence and I have linked some research papers if you would like a more in-depth analysis, but there are many more scientific journals out there.

Myth 1 – Exercise is bad for your knees

Actually, it’s more like the opposite; properly done squats will strengthen the stabiliser muscles around your knee joints and improve mobility and flexibility. Weight lifting can thicken your ligaments and cartilage as well as help with pain and discomfort from arthritis.

Strasser, B., et al (2011). The effects of strength and endurance training in patients with rheumatoid arthritis. Clinical rheumatology, 30, 623-632..
Vincent et al (2019) PMID 29917242

Myth 2 – Poor posture is bad!

‘Good posture’ does not prevent back pain or hip pain and bad posture doesn’t cause it. There are many studies into this and the whole drive for good posture stems from visual desire over physical performance. Bottom line is that posture is overrated, and good posture doesn’t really exist.

Swain et al (2020) PMID 31451200.
Slater et al (2019) JOSPT, 49(8)

Myth 3 – Lifting heavy weights makes me bulky

Strength training doesn’t automatically make you bulky; it is often said that it does to persuade generally women to stick to lighter body weight exercise classes. Instead strength training will make you stronger and lower your risk of injury and fractures from falls and give you that all important toned look.

Wendel, A.Why Building “Long and Lean Muscles” Is A Myth (And How You Can Get Strong and Lean!).
McGrath, S. A et al. (2009). Normalizing gender transgression through bodybuilding. Sociology of sport journal, 26(2), 235-254.

Myth 4 – Exercise turns fat into muscle (abs for abs)

No amount of exercise can counter a poor nutrition plan. Just because you do hundreds of crunches per week doesn’t mean the abs will pop out. The abs have always been there you will just need to get onto a calorie deficit by eating less ultra processed foods and increase your fruit and veg intake (easier said than done I know.)

Phillips, S. M. (2014). A brief review of critical processes in exercise-induced muscular hypertrophy.Sports Medicine, 44, 71-77.
Sherman, J. The Effects of a Calorie Deficit on Body Composition. The Undergraduate 2020 Spectrum, 28.

Myth 5 – You should always do a warm up and cool down

Although there is good evidence on the benefits of warm ups with respects to performance and injury prevention. Don’t waste your time on a treadmill, static/dynamic stretches or mobility drills if it means that you sacrifice on your strength training, if you want a short warm up for squats then do some lighter squats. The closer the warm up resembles what you are about to do the better. Cool downs on the other hand have been shown to delay your recovery if not make it worse.

Blazevich et al (2018)PMID 29300214
Afonso et al (2021)PMID 34025459

Myth 6 –  Young children should not lift weights

The physical activity guidelines from the NHS website state that children from the ages of 5-18yrs should be getting at least 60 mins of moderate to vigorous aerobic activity in per day! Plus movement skills and resistance training at least 3 days per week to help develop bones and muscle strength which can include sports, gymnastics, body weight exercise and weight training. Weight training from a younger age has shown improvements to ligament thickness and is not harmful to children’s development.

NHS physical activity guidelines for children
Grzelak et al (2012) PMID 22447073
Faigenbaum et al (2017) ACSM

Myth 7 – I just want to tone my muscles

It is a complete myth that muscles are soft and that you need to train with light weights and high reps to make them hard. Muscle only increases and decrease in size so if you want to ‘Tone’ you should do strength training and have a good nutrition plan.

Phillips, S. M. (2014). A brief review of critical processes in exercise-induced muscular hypertrophy. Sports Medicine, 44, 71-77
Snijders, T et al. (2017). Muscle fibre capillarization. Journal of cachexia, sarcopenia and muscle, 8(2), 267-276

A girl using a fitness machine in the gym at Cofton

Myth 8 – Cardio is best for weight loss

There was an interesting article by Dr. Michael Mosley where he makes the bold claim that cardio doesn’t help with weight loss. He is right if you cannot maintain a calorie deficit. Cardio exercise is more systemically demanding which will make you more hungry meaning that you eat more thus not sustaining a caloric deficit.

Ballantyne, C. (2017). The Great Cardio Myth.
Sherman, J. The Effects of a Calorie Deficit on Body Composition. The Undergraduate 2020 Spectrum, 28.

Myth 9 – No pain no gain

This is a load of nonsense. You can get health and fitness benefits from working at as little as 50% of your max capacity for one session per week of resistance training. If you want to progress with your strength, conditioning and toning then you need to go to the gym at least twice per week and also get 150 mins of moderate aerobic activity in a week with a healthy nutrition plan.

NHS physical activity guidelines
Behm, D. G et al (2023). Minimalist training: Is lower dosage or intensity resistance training effective to improve physical fitness? A narrative review. Sports Medicine, 1-14.

Myth 10 – You can get hurt lifting weights

The gym is the safest place for you to get strong; much safer than hiking in the hills or playing sport. Machines are designed to be super easy to use and you can’t use them in the wrong way as they mostly only do one movement. If you are going to hurt yourself, you are better off doing it trying to get stronger as you’ll be better for it. Lifting technique isn’t so important that you should avoid exercise and lifting heavy weights without a neutral spine hasn’t been shown to cause greater risk of injury. Stronger people are less likely to get injured.

Saraceni et al (2020) PMID 31775556.
Kadlec et al (2023) Sports Med Open,9(1)


If you’re looking for help to achieve your personal fitness goals, our one-to-one Personal Training service offers a program tailored for you. Our Personal Trainer Lewis, is available to offer both fitness and nutritional advice as well as Personal Training programs. Please contact our Leisure Desk where one of the team will be happy to book you in for a consultation with Lewis.