Originally Posted by
meanwhile
Actually that's been absolutely disproved - at least in the sense you mean it. If you'd check that link I think it would show that the HIIT group did much better than the steady state cardio group despite doing less work in terms of calories. This result has been replicated many, many times since.
No, simply not true. In fact it is easily demonstrated. People who reduce their calorie intake by 500 cals per day will loose about 1 pound per week (3600 calories). The last major demonstration was the nutrition professor who lost weight on the twinkie diet. He controlled his calorie consumption and lost weight at the predicted rate. Indeed by your own admission, those who don't follow HIIT, the control group, still lost weight.
Exercise is not needed for weight loss. It does help, but isn't needed since weight loss is a energy equation.
Originally Posted by
meanwhile
What you're failing to allow for is that the body is a complex system with varied capabilities and can choose to spend metabolic effort provoked by exercise on either eg replenishing fat stores or building muscle. Obviously if you want to lose fat you want the second! And which of this options it chooses depends on how much work your muscle cells did using the three energy cycles available to make new ATP for them to burn - which depends on the type of exercise you do, especially the intensity.
Oh - and you're also failing to allow for the fact that different sorts of exercise will lead to different **resting** metabolic rates.
The difference between steady state cardio and HIIT gets even stronger in older exercisers - after around 50, HGH production declines. Raising the HGH level signals the body to store less fat. Both HIIT and suitable weight programs raise HGH. People who have problems keeping a reasonable weight may have HGH to begin with - although, in the US especially, diet is a more common cause.
If you want a decent text that explains this in reasonably accessible terms then the "Kettlebell Bible" is pretty good. One of the authors was the Royal Marine Corp's senior PTI noncom and seems to have spent a lot of his time reading endocrinology papers - Full Metal Jacket it ain't. Just be prepared to learn a fair amount of muscle cell biology. There are kettlebell exercises in the book, but the guy really does spend more time on the Krebs and Coroli cycles and the implications of the Golgi tendon organ for stretching.
I've heard that "Body By Science" is an ok book as well, and not nearly as painfully technical.
Oh - and also on the calories are calories thing, the metabolic path for fructose is weird - it's processed like alcohol rather than other carbs and can even cause liver scarring in the same way. So, physiologically speaking, no.
Much of what you say is true, but the conclusions you are reaching aren't. Yes, programs that increase muscle mass will yield a higher metabolism and faster weight loss. That is a given. The problem is that unless one wants to live that life style for the rest of ones life (not really feasible--how many retiree weight lifters still have those physiques?). Precisely because muscle mass is metabolically costly, the body will shed muscle mass in preference to any other tissue if it isn't needing that muscle. And needing means that the muscle is being used regularly. So if you are doing intervals or lifting weights and stop you loose the benefits. Your muscles will quickly atrophy, your metabolism will slow, and you will have to relearn how much to eat to avoid weight gain.
However, low levels of exercise are something that can be maintained until ones deathbed. So while the weight loss will be slower, it will still occur and the new lifestyle is maintainable until death... Which is one reason it is what the vast majority of doctors (at least the ones who aren't selling diets) recommend.
The recommend program will not produce bodies with the same low (5-10%) bodyfat percentages as what you are describing, but that isn't a bad thing. Our bodies are intended to have a slightly higher level of body fat, which is why the low levels obtained by the programs you discuss are so hard to maintain.
Moderation in diet and exercise are the better coarse for people.
Oh, and the calories are calories thing as you say is both true and easily demonstrated.
However, it only refers to weight loss. Nutritionally there are of course differences, which is why a healthy balanced diet (40-50% carbs, 25-30% protein, and 25-30% fats) using vegetables and whole grains as the source for the carbs, and lean meats for the protein and monounsaturated fats is the consensus recommendation.