For the most part, you should run the other direction from crash diets, fast fixes, and “one weird trick” solutions. But with summer upon us, there is at least one exercise you can still deploy in the last couple of weeks that will make you appear noticeably slimmer when you hit the beach.

It’s called the ‘stomach vacuum’, and it’s an old bodybuilder standby, used by competitors to achieve the waspish waist that was the hallmark look of that sport’s golden era.

The stomach vacuum works the transversus abdominis (or TVA), a deep postural core muscle that serves as essentially a natural corset, holding in your guts. Improving the maximal contractive strength of the muscle also increases the muscle’s tone – its degree of resting contraction. Which, as a result, will carve an inch or two visually off your waistline, even in just two or three weeks.

Here’s how it works:

1. Ideally, do this first thing in the morning. Or, at least, on an empty stomach.
2. Start lying on your back, with your feet on the ground.  
3. Take a full breath, then exhale through your mouth until you've blown out all the air.  
4. Once your lungs are empty, pull your bellybutton down to your spine, as hard as you can. Really pull it down; the harder you pull, the closer to your spine your bellybutton gets, the better this works.
5. At the same time, try to make your chest as big as possible (i.e., lift your chest up), though while still pulling down hard on your bellybutton.
6. Hold that for 15 seconds.  
7. Then relax, breathe normally for 15-30 second, and repeat, 2-4 times more.

If you stick with this exercise over the course of the summer, you can slowly increase the duration of each hold, adding 5-10 seconds each week, until you’re holding for 60 seconds for each of your 3-5 sets.

Again, this should drop two inches off your waist in just two to three weeks. And, as a bonus, engaging your TVA improves power transfer in athletic movements, and may even protect your low back from tweaks and injuries.

Suck it up, indeed.