I've been working with the Men's Health Ultimate Iron-Free Circuit Series workout recently. Basically, it's seven different bodyweight exercises done without rest, alternating between an upper- and lower-body exercise, then rest a minute, and do the whole thing again. You start with two sets. . And, I've been getting good results from it.
I added a third set of it today and the results I'm feeling are really good. Definitely feeling it more in my shoulders, from the extra sets of close-grip and t-pushups. But I also felt it from an exercise that I didn't think I was getting much out of, but was doing because it was part of the routine. It's called the inverted hamstring.
I figured it was getting me some good balance work and that was about it. But today, I really concentrated on doing it slowly and keeping my balance all the way through it. It's still not as exhausting as some of the exercises, like the aforementioned t-pushups, but today I'm feeling it much more in my upper hamstrings, where they meet my glutes.
And that's one of the things I love about exercise - just a small change and some more concentration on form can make all the difference and let you know how your body is working for you. Our bodies are a sum of all the parts, not just a bunch of big muscles that we can isolate to look huge. And true functional fitness comes from the big movements that use lots of muscles, not things like wrist curls and bench presses and the like - but from exercises that challenge the whole body and force it to support its own weight.
And it goes further than that - body and mind are one unit, so a strong body can mean a strong mind. But you have to work both properly and conscientiously to strengthen them.