If that particular program works for you then it is, by definition, good.

But weight loss and conditioning is not an unknown process.

Weight loss is, at its core, a simple matter of input versus output. If you take in fewer calories than you burn you lose weight. It is really hard to work hard enough and long enough to lose significant amounts of weight because the human body is very efficient. Running a marathon only burns around 3600 calories. About 100 calories per mile. Three miles for a 300 calorie energy bar.

Considering that many of the larger fast-food burgers and popular shakes have more than 1000 calories each, some combinations of burger and shake meals could get you through a marathon, it is clear that it is going to be far easier to limit what you take in than burning off a unrestrained diet.

http://www.acaloriecounter.com/fast-food-calories.php

It also has to considered that some of the weight lost from exercise is little more than dehydration. Exercising hard in Florida heat it is easy to lose a quart of water, about two pounds, an hour. People who resist, or fail to feel, this dehydration and compensate can lose considerable amounts of weight but may be putting themselves at risk.

It is entirely possible to build endurance and lose weight with moderate exercises like walking and swimming and relatively minor adjustments to diet. Dedication and constancy are far more important than intensity.

It also has to be noted that even a relatively minor injury to ankles, knees, or back can bring any exercise program to a halt and that as we all get older it is wise to shift toward lower impact and less stressful methods. Walking, yoga, swimming, simple calisthenics, and low-stress spinning are less likely to do damage as long as you pay attention.

Contrary to popular belief exercise doesn't need to hurt to benefit you.