The M7 Max Trainer is a pretty cool Machine.

I got one and I'm not endorsing it or trying to say you don't need to watch your diet or anything like that. But it's a really great cardio machine. It's very loose on your joints and it's very easy to get your heart rate up. Whenever I do a stationary bike or an elliptical machine it requires so much more mental focus to try to keep my heart rate up. In theory all that matters is that you keep your heart rate up, but with those machines you have to be totally mentally zoned in just to keep it at around 140.

With the max trainer, you can either do HIIT workouts or longer, steadier workouts. It's sorta like stairs, but like an elliptical but more challenging. It's that little sweet spot with rotation that makes it easy for me on the joints. It doesn't take a lot of mental effort to keep your heart rate up high because the motion that you're doing is like climbing stairs. I'm not sure that it's as hard as climbing stairs, but because it's such a smooth motion, it's not very hard to push yourself just a little to get your heart up.

To be honest, I don't know why gyms have so many ellipticals and stationary bikes. They are inherently very easy. Sure, you can push yourself on them to get your heart up. But with stair motion machines, you don't have to try as hard to get your heart up. You don't have to focus even half as much. So don't listen to people that tell you that all that matters is that you get your heart rate up. In theory that's true, but imagine trying to get your heart rate up using only arms. It's not as easy as you think. It's all about using bigger and more muscle groups.

Some people just like regular stair masters. I have no issue with them, but the reality is not everyone can do them all the time because of the pounding. Some people talk a big game and they say you have to do them or you're just a wimp. But these people don't have any joint issues yet so it's easy for them to say. The cool thing about machines like the max trainer is you typically don't get any joint pain from them. But way more potential to increase your heart rate than an elliptical.
You can get your heart rate up with an elliptical, but you can get it up easier with a max.