People spend hours upon hours in a gym trying to get healthy, stay healthy, or convince themselves they're healthy. Regardless of whether or not they are, the real question that begs to be answered is, "is working out in a gym the healthiest choice"? The answer in my opinion is no. Sure it is beneficial when compared to not working out at all, and is probably ideal during those cold harsh winter months, but when it comes to the "perfect gym" you can't hold a candle to what nature has to offer.
The best example of this can be seen in much of the equipment you pay to use. There is a lot of engineering behind much of the cardio equipment that are popular in most gyms (bikes, treadmills, steppers, etc.), but if you look closely at all the bells and whistles this equipment has to offer you will begin to see what the designers behind the equipment were trying to mimic. With all of the programmable workouts that can be used; incline, decline, fast, slow, or a combination of all of them, it becomes plainly obvious that someone is trying to duplicate what nature provides for free.
So the next time you feel the need to use the stepper or treadmill, consider visiting you're local park or state park and go for a hike. You may find out it's the best workout you’re not doing!