Not everyone there is a size 8 gym bunny or a god-like muscle man with a rippling six pack.
There may be some people with good bodies. They'll most likely have been actually going to the gym for a while!
The vast majority are just normal people like you, perhaps carrying a bit of extra weight and wanting to get rid of it.
You are at the start of your weight loss and fitness journey, these people may be a bit further down the road but you've got to begin somewhere.
With GPs now prescribing exercise for weight loss and many exercise referral programmes taking place in local authority gyms you are more likely to see bigger gym goers.
"Our members are average people, not elite athletes, so our centres are full of individuals of a broad range of backgrounds and experience and all shapes and sizes," says Tiffeny Cutts, who's the national exercise referral manager for the Everyone Active chain of gyms and leisure centres.
Go with a friend, it'll make you feel less nervous. There'll be someone to chat to and have a laugh with if you feel a bit clumsy or out of your depth.
Pick an area in the gym where you feel comfortable and that doesn’t make you feel anxious.
Remember no-one's looking at you. Other gym goers may glance in your direction to see if they know you but they won't be judging you. "Size really doesn't matter, people are usually so focused on their own work out to be watching or paying any attention to anybody else," says fitness instructor Pip Dicey.
Pick the right gym. Have a look at a few gyms and choose the one you feel most relaxed in. There are women only gyms if that would suit you better. Or if you are a man looking to build muscle you may prefer a gym with a wider selection of weight machines and free weights.
2. You don't know how to use the equipment
The equipment in gyms can look a bit high tech and complicated, all screens, monitors and bleeping this and that!
Don't worry as it's all quite intuitive once you've been taught how to use it.
Maybe try to get to grips with two pieces of equipment at first so you don't get brain overload! Maybe the static bike and the treadmill, which allows you to walk, jog or run.
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