Self resistance exercises have been around for over 100 years. The main proponent for them was Bernarr Macfadden, the father of physical culture in the US. One of his main contributers, Dr. Fredrick Tilney, teamed up with Charles Atlas, about 1922, and they created the Charles Atlas course. That course became Dynamic Tension in 1928 when Dr Tilney sold his part of the business to Charles Roman, a marketing genius. Self resistance is pitting one muscle group against another. Besides body weight exercises and calesthenics they are an apparatus free way to exercise. As an introduction to them I'm posting 2 articles here on them. The first is from Macfadden's magazine Physical Culture, and it ran in the April 1900 issue: http://www.sandowplus.co.uk/macfadden/pc-resisting/pc-resisting.htm The other was published in Muscle Media magazine in September 2002. When you get to the page scroll down about 6 articles to the Muscle Media with the article on the Titans of Fitness. Download the pdf and the exercise examples are on page 6: http://charlesatlas.com/whatsnew.html What a difference pictures make. You could easily run the Macfadden article today by only updating the photographs. A lot of contemporary writers on the Atlas course keep calling the exercises isometrics, and they aren't. Dynamic Tension was actually a good name for them, dynamic means motion and tension speaks for itself. So it's moving against tension. The Macfadden article says to use enough tension to do 20 repititions. The Muscle Media has 3 sets of 10. If you try these, believe me, start with one set of 8. In the curl really resist with the one arm as you curl against the resistance. The key to these exercises, I've found, is to tense the muscle being worked as you start the positive motion. But really try to get the feel of doing them right. The great thing about self resistance exercises is you can do them anywhere. The Atlas course and other Macfadden publications have a number of other exercises for the arms, shoulders, back, chest and legs. I know of 2 people who claim to be working on manuals using self resistance exercises. The main problem with the Atlas course is the instructions on how to do them are not very good, it needs a rewrite by a good technical writer, and editor. I'm mixing SRs with body weight right now. I'll do this for a few months then switch to bodylastics for the resistance. If you travel they are a good way to workout while on the road.