Phenomenal and most of all do-able. This Pilates book has the best explanations and illustrations of all the ones out there. I know, I was in the mall and I checked them out.
I bought this book over 6 months ago, as I felt I needed more than just a regular workout on an elliptical machine. I wrote a review on it shortly after I started and I wanted to update that as a number of people have emailed me for more information.
Some background. I'm 43, female and 25% overweight, not exactly your svelte exerciser, so I knew I needed a routine that wouldn't hurt but would would get results. I work in an office and nothing is worse than sitting at your desk all day aching from the previous day's exercises.
I started as recommended with Modified beginner exercises, the seven basic exercises and did this for about 3 weeks. No pain but some tightness I could feel in my abdomen. As I became confident, I moved onto the regular beginner exercises. Basically, I used my ability to do the "hundred" as a measure of when I was able to move on. I could see my progress from day to day. It was really neat. I did the exercises at least 5 days/week.
As time went on I added more exercises from the full program. One or two each week depending on if they were similar or really hard to do. Some were, some weren't. Still no pain. I am now doing almost all (over 95%) of all, but the advanced exercises at least 5 days/week along with my elliptical machine routine and some weight lifting for my arms. I don't have time, I make time. In my opinion, this is as important as paying my bills. In someways, this is just what I'm doing.
One question, I have been asked is am I seeing muscle definition. The answer is definitely yes. I am still overweight. I'm working on that too (I've lost 25 pounds through just exercising), so I'm not seeing a washboard stomach, as the fat above the muscles are still obscuring them, but I can see definition of my ribs and hips, along with distinct muscles in between. This is nothing I've ever seen before, even in my skinny high school days.
One interesting measure of how far I've gone is watching my teenage children trying to mock me doing the exercises. Both are slim and in good shape, but neither can dive in and do the intermediate exercises that I'm doing with the same ease I am. In fact they are shocked they can't do more than a couple repetitions. Not because it hurts so much, but because they have not build up the strength.
That is another thing that I mentioned in my previous review, these exercises provide the feedback you need to continue on. You see it in each day in each exercise as they become easier. Also you see it in your day to day tasks.
For me, it was an excellent investment.