For the past 10 to 20 years functional fitness training has become a mainstay. By functional I mean that the movements mimic movements of daily or sport activities and don't isolate muscle but rather integrate. Tell me when you have only lifted something with your biceps in daily life. You just don't; you use multiple joints and multiple muscles. Also, increasing the stability requirements of an activity make it harder because more muscle fibers need to be recruited to perform the exercise. (Exercise balls are unstable surfaces and therefore require you the use more "core" muscles to perform the exercise)
Anyways, I have wanted some gymnastic rings for different kinds of pullups, pushups and reverse rows. They are a great piece of fitness equipment. You can buy them from Elite rings for $80 or make them for a fraction of the price. Here's how I did it.
Step 1: What you need & Prices
You will need:
2 x 12 feet lashing straps (Harbor Freight Tools: $3.99)
20 feet of 244 lb capacity nylon rope (Harbor Freight Tools: $1.47)
2x 1" x 24" pvc pipe (Home Depot: $1.43 each)
A 1 gallon paint can