If you are considering the "SPRI ES503R Xertube Resistence Band (Purple, Very Heavy)" as a substitute for your gym membership and for the gym's free weights, you may want to look elsewhere.  The Xertube Resistance Band is a very good way, for those of us pushing the "new 40," to maintain muscle strength; the Xertube will not transform you from a 98 lb. weakling into Adonis with a six-pack.