You can hardly be blamed if your abs took the winter off.

We’ll let you slide on spring, too.

But now we’re getting into prime take-your-shirt-off season.

So you either change hemispheres... or you join a gym.

The easier choice is probably Speedflex, a high-tech fitness lab that couldn’t have come at a better time, open as of today in Preston Center.

This isn’t your average gym. For starters, the hardwood-floor-and-glass-walled facility is sporting 10 machines that you can’t find just anywhere. Sure, you can find them in London and Dubai, but not just anywhere. And those machines use smart hydraulics to match your resistance level. So however much force you put out, the machines respond with equal force. Nice one, science.

To get started, sign up for a trainer-led group session. Those last about 30 minutes, and they’ll keep you moving from machine to machine in circuit fashion, doing squats, shoulder presses, power cleans and other high-intensity things that are good for you.

And all the while, you’re wearing a heart rate monitor that’s reading all your vitals and displaying them on one of the big screens above.

Try not to flatline.