8 fitness excuses you legitimately use that definitely aren't valid. (Sorry.)

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We’re all aware of those fitness excuses we make that aren’t really valid excuses (“but my favourite gym pants are in the wash”, ring a bell, anyone?). But without realising, those more “valid” excuses you use aren’t so valid after all.

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Don’t worry – we’ve done them all too.

Excuse 1: I’m sore from yesterday’s workout.

Having an injury is one thing, but if you’ve got the normal aches and pains from your workout, it’s actually a good thing.

“It’s called Delayed Onset Muscle Soreness (DOMS) and it’s actually an excellent thing to have – it means you’ve done the right stuff,” says Thamsin Dunn, National Master Coach, Fitness Instructor and First Aid for the Australian Institute of Fitness.

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And exercise can actually make it better.

“Light exercise can decrease the pain, helping to get toxins out of the blood. The nervous system also rewards you for exercising by masking the pain, as your body modulates itself. All this comes together and can actually help you to heal faster,” she says.

“This will then help you establish good habits, and means you’re actually more likely to do more exercise in the long run.”

 Excuse 2: I’ve already exercised plenty of times this week.

While it’s great if you’re hitting the minimum recommended amount, the truth is you can never really do too much exercise.

“In fact, doing plenty of exercise on a regular basis will actually give you the momentum to form good habits,” she explains. (Post continues after gallery.)

Excuse 3: I just don’t have any time to exercise.

You don’t need big blocks of time to exercise, says Dunn.

“Studies have found that doing 10 minute bouts of exercise three times a day is just as effective of doing 30 minutes straight, provided you keep up the intensity,” she says. (Post continues after gallery.)

And if that’s too difficult, don’t underestimate other ways you can integrate it into your day, including incidental exercise.

“I had one client do squats while he was brushing his teeth!,” Dunn says. “Also if you get public transport, consider getting off one stop early and walking the rest.”

Excuse 4: I’m just too tired.

“Exercise actually improves your alertness, because the release of adrenaline perks you up and increases your blood sugar” explains Dunn.

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“People who regularly exercise report feeling more alert during the day and also better sleeping patterns,” she says.

Excuse 5: The gym is way too expensive.

You don’t have to spend big money to get big results – most of the best exercise can be done absolutely free.

“Just go for a jog, or even try joining a social sports team,” advises Dunn. “That way you’re making a commitment with an incentive to regularly attend and it’s usually not very expensive either.” (Post continues after gallery.)

“There are also plenty of easy-to-follow workouts on Youtube that you can do from your own living room.”

Excuse 6: But it’s too hot.

“Go for a swim,” says Dunn. “Not only is it one of the best forms of exercise, it’s a lot of fun and there’s really nothing better than swimming when it’s really hot.”

Excuse 7: But it’s freezing.

No, not even this one is a cop out.

“Exercise actually increases your core temperature, and keeps it raised for hours after you’ve exercised, meaning you’ll actually be warmer for longer than if you’d stayed in bed,” she says.

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“If it’s really freezing, why not exercise indoors with the heater on?”

Excuse 8: I'm pregnant.

"If you were active before you're pregnancy, it's actually really important to remain active (albeit with adjustments) during pregnancy, as your body can find that,on top of all the other changes, quite stressful," says Dunn.

"After the first trimester, things like taking a gentle walk is great and it can also help alleviate morning sickness."

RELATED: 5 things every pregnant woman needs to know about exercise

"It also has a whole host of other benefits, including keeping muscle mass strong so your body can cope as it grows during pregnancy, removes toxins from your blood and manages blood sugar levels," she says.

If you're pregnant, talk to your doctor about an exercise plan for you.

What's your go-to excuse for not exercising?