If you were allowed only one piece of exercise equipment for the rest of your life, which one would you chose?
Suspension training. With your feet or hands touching the floor or ground, you suspend your body between two heavy duty nylon straps and exercise against your own body weight.
Cost is minor. A complete Woss suspension rig, including the ceiling mount, is about $50 The better known and slightly fancier TRX rig is still affordable at about $200.
The idea was conceived by a Navy Seal as a means of providing a challenging workout while deployed where a gym was unavailable.
Suspension training engages your core muscles constantly, since virtually all exercises involve a plank position. There is also constant challenge to stability and the effort required can be adjusted by simply moving your starting point toward or away from the anchor point.
You can use it anywhere. It comes with long straps that allow you to wrap it around a tree limb or post. It also comes with a door mount.
There are dozens of exercises you can perform, challenging every muscle group. They range from relatively easy to absurdly demanding. And, since you can increase or decrease the effort by simply moving your starting point, you can readily increase the challenge of each exercise as your strength improves.
And the whole rig fits into a small storage bag that weighs maybe three pounds.
While no exercise system may be appropriate for everyone, suspension training comes close. I've been using my Woss rig three times a week for more than a year with no injuries or ill effects, and I'm 75 years old.