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Sunny Health and Fitness Asuna SpaceFlex Review: Small-Space Cardio That Actually Fits

John Carter Doe

September 3, 2025

8.6

Very Good

Should you get the Asuna SpaceFlex?

Here's where it really shines

Look, if you're tight on space and just want a simple treadmill for walking and some light jogging, this Asuna SpaceFlex really hits a sweet spot. It folds up vertically, so you get your floor space back in a flash, and it rolls around easily. And here's the thing—it feels a lot more stable than most of those other 'mini' treadmills you see in this price range. The deck has enough cushion for your daily steps, and the console is just... simple. No subscriptions, no hidden fees, and you don't need a manual to figure it out. And the noise? It's pretty apartment-friendly. The motor hums a bit, but your TV will probably drown it out. Bottom line: it’s a compact, low-drama machine from Sunny Health & Fitness that makes getting your steps in way easier than arguing with the weather outside.

Should you get the Asuna SpaceFlex?

But let's talk about the trade-offs

Let's be real, any space-saving treadmill is going to have some compromises. The Asuna SpaceFlex has a shorter deck than the big, full-size models. That means if you're tall, or if you're trying to run fast, you might feel a little cramped. Its top speed and power are really designed for walking and light jogging—it's just not built for all-out sprints or training for a marathon. The console is basic, too. You get your essential stats and a few programs, but don't expect the fancy training metrics or connected apps you'd find on more expensive machines. Its weight capacity is also a bit lower than the premium models. And, like with most of these compact decks, you'll want to stay on top of keeping the belt aligned and lubed so it runs smoothly.

So, here's my take. If you mostly walk, live in a small apartment, and absolutely need something that folds flat, then yeah, the Asuna SpaceFlex is an easy choice. But if you're on the taller side, want to run fast, or you're craving more training features, you'll want to look for something with a longer deck and more power. For runners, I always suggest a deck that's around 55 to 60 inches long—it just feels safer when you pick up the pace. Still not sure? My advice would be to put the SpaceFlex on your shortlist for walking and jogging, but definitely compare it to a couple of full-size foldable models before you make the final call.