Well, you’re a SELF reader, so it’s not because your routine is boring!

Nobody quite knows the cause of the involuntary action.

The biggest risk you run from squeezing in sweat sessions post-meal: stomach cramps.

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But exercise redirects that blood flow to your muscles, which can cause your stomach to spasm.

Bottom line:You could forgo your after-dinner session for an earlier lights-out and sweat in the A.M.

But if nighttime is your only window, stick with it.

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once you’ve kicked off the sneakers.

The workout is a huge phenomenon.

Millions are shaking it in Zumba classes to music mash-ups, including salsa and hip-hop.

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Not sure what to wear?

Cross-trainers are key for the side-to-side movements, Beardsley says, and wacky, bright outfits are de rigueur.

Bra bulge and bat wings are everyone’s nemeses.

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These creative SLT toners hit every muscle from the waist up, plus a few bonus spots.

(Trust me: You’ve never used a stability ball like this!)

I have the same issue with my husband.

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Of course you still want him to be healthy.

Which means more O-mazing sex for you both.Nowwho wants to get moving?

I got the dirt from my sis, Erin Kurdyla, who has conquered several sludge fests.

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But as tough as they might look, they feel more like a party than a competition.

“It’s such a blast, you don’t realize how hard you’re working!”

Dress the part.Wear scroungy workout clothes and sneaks that you’re fine with throwing out.

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His top tip: Wear reflective clothes.

Thankfully, there are lots of stylish options.

(No Day-Glo crossing-guard vests!)

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Left: The Speed Run Cap 5 is 53 percent more visible at night than plain white is.

And each dot on the confetti-patterned Run: Around Shorts is reflective.

Put your head in a positive place by creating mini-goals (which become mini-victories!)

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to overcome your obstacle.

Nervous about dunking your head underwater?

Keep submerging, inch by inch, until you feel calm.

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Afraid of clipping into bike pedals?

Practice over and over in your garage before you hit the streets.

Exposing yourself to your fear gradually gives you confidence and encouragement to keep going.

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Finally, as you tackle your activity, remember these three tips: Talk yourself up.

(Repeat phrases like “I can totally do this!")

Concentrate onhowyou’ll succeed (“How many strokes should I take before the next breath?

“), which helps distract you from worries about failing.

And focus on the now.

Because it’s not about what happened last time; it’s about succeedingthistime.

For the quickest payoff, we boiled it down to the essentials: asexy-sundress-arms workout.

In a week, you’ll start to see results that will send you sundress shopping.

Try thesexy-sundress-arms workout, and view thehow-to video.

But Newman’s case was incredibly rare.

Find your perfect workout.