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I was working out four to five times a week, and I actually really enjoyed doing it.

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Cristina Cianci

I felt like my eyes had finally been opened to all the endless possibilities in the fitness world.

Then, in the spring of 2017, I started covering fitness exclusively.

It became my sole job to give people smart, actionable, research-backed information about exercise.

Im now an ACE-certified personal trainer.

Better late than never, right?

This doesnt mean Im suddenlyJillian Michaels.

There are a lot of things that impact flexibility, like your age, gender, and past injuries.

The one factor I find most fascinating is the time of day.

Heres how it works: We have discs of cartilage in our spines, stacked in between each vertebra.

When we lie horizontally all night, the fluid basically flows back to where it belongs.

This means that when we first stand up in the morning, these spinal discs are a bit swollen.

Swelling translates to a stiffer back, and consequently a smallerrange of motionand greater risk of injury.

Squatting is considered acompound exercise, which means it involves multiple muscle groups at once.

One thing I never really thought about was how myankles are involved in the move.

Well, the length of your limbs actually plays a role in reaching those strength gains.

That means you need less muscle force to lift the weight than if the limb were longer.

In addition, studies have shown that restricting knee movement can seriously stress the hips.

(Think of pushing your butt back as if youre sitting down in an invisible chair.)

Youre actually training your brain to lift.

That is, the mind-body connection is a real physical thing.

Thats a fun fact.

Turns out, that formula has been found to be wildly inaccurate.

I think I read the word self-efficacy 100 times in the ACE personal trainer manual.

If you dont believe youll succeed, why would you put yourself through all that work?