Well I can assure you that the FAT buring Zone dose exsist, but may not be suitable to all athletes, or Fitness fanatics.
The problem is that low intensity training is better for muscle building, hence the reason why body builders bulk up, those not on steroids. Once you know how to handle the zones of fat, carb and protein burning too, you will have more trust over your own abilities to apply it.
I don't have to tell you that all people should be concious of the pit falls of diabetis, hence the reason to understand, healthy eating, healthy eating = low GI foods, for prevention and control.
I can also say, that if your body has no need for carbs, and protien, it will both be converted to the fat depot. So getting it right is a very fine line, for everyone.
I only ever tried supplements twice in my life, that was in my early 50's, i was intent on building more muscle for about 6 months and decided to supplement with protein drinks, becuase i wasn't eating steak and eggs, like i used too in my youth, the worst thing for me, i ever did was to take, supplement.
I bulked up to 98kg with 26kg of it FAT, big mistake so i stopped the supplements. The next 6 months I spent losing 1kg per week, training 3 days a week, by enhancing the metabolic path ways, with every amino acid listed in the metabolic system (Krebs Cycle) to do that I drank a vinegar, made from brown rice, which supplied the essential acids, for the metabolism to work optimal. One can eat all the food, veg and fruits one wants, but can you still guarantee, you are optimising the metabolic burning? Only if you can document the amino acid intake for the metabolism!
http://exercise.about.com/cs/cardiowork ... 22601a.htm
My Singaporean brother -in- law is also type 2 dietbetic and drinks the vinegar to regulate his blood sugar, obviously type 2 suffer, their own sensitivity to vinegar, although their are no additives at all, and the fructos is from the fruit it is fermented with, and not corn fructos. There is also a dietbetic vinegar, available because they are brewed by agricultral chemists, using TCM.
Vinegar actually helps dietbetics by converting high glycim food into low, by attacking and breaking down the sugars, reducing actual sugar spikes by around 30%, continued use will lower blood sugar, and is very easy to document yourself, by a quick blood test once a month.
Back to Fat buring Zone, sprinters, joggers and most runners use a lot more carbohydrate calories than weight lifters.
So carbs are what i call the emergancy fuel, you can use it all up within 20 to 30 minutes of intensive exercise, what the body will use next is protein and fats for fuel, obviously their are more calories in the fat, so it will be seen to reduce more slowly, protien being easier to burn with less calories, this is why most people cannot put on muscle.
Understanding the carb and fat zone is very important to certain individuals and not others, weight lifters and body building is almost always in the FAT zone, hence you can junk out on almost anything for weight lifting, but need to be more protien orientated with body building and muscle.
For myself who enjoys all sports and do not focus one, but builds endurance through intensity training, which not many people in the gym do.
But if you can take the treadmill to 20km per hr, for 20 to 30 second bursts, you will know about exercising the heart muscle and for mountain running you need it.
It normally takes me 3 weeks before doing a 8km attempt for a up hill jog, and if i stopped for longer than 3 to 4 weeks, I would have to start again from scratch. That's how quickly one loses fitness.
When doing the treadmill in hospital after the heart attack, results cannot be measure, because my heart is very healthy and strong, when fit 42 BPM unfit 48 to 50 so a 15 minute treadmill test does nothing for me at all, i don't even break a sweat and the incline is not steep enough to challenge my heart.
All said and done, I would suggest that you do not give up on Fat burning zone, but to dig deeper to understand it, simply because it is a requirement for the weakest of people, but not the quickest way to burn calories, but you know that new clients cannot even consider high intensity trg or even moderate for some, it's a slow process and for obese people it is important for them to set goals, to at least get in the fat buring zone by walking.
So max pulse rates of individuals and buring zones are for everyone to understand the chemistry of burning fats, carbs and protiens, the major point is that everything in the food chain gets synergised into what the body is needing, if it doesn't NEED it, it gets stored in a glucose form in the skin, until it is needed, along with water.
A weight lifter will never do high reps if he is strength building, and a body builder will bulk with a good mix of the three carbs/pro/fats for muscle building to suit his own needs, finding the right combination mix, for it to work can only be done through logging the data, cutting the muscle is a fine art and technique, done mostly by experienced coaches in their field of practise. So even coaching becomes very important to focus on what you are good at!
If you are in general fitness, then a wide knowledge is fine for the general public, but many people searching for answers want the right answers.
So BS isn't a good idea, it's better to say I do not know, but I will find out for you so that you do not damage your reputation as a coach.
I have seen Chinese coaches that can never put on weight with superb muscle definition at 180 cm tall but only 70kg in weight, these people have to except the gentetics, they have, no matter how hard they try to put weight on, they will fail. My belief is that everyone should be concious of the GI of foods, and follow a low GI plan, with the occassional HGI food if one enjoys it.
What is ATP search wikipedia and find the answer, then look at the metabolic cycle, which turns around 1500 cycles a day for the average person, producing 1 ATP per cycle...The quality of ATP is essential to the fatigue or endurance that you will feel through out the day, so if any of the 8 essential aminoacids in the cycle are missing, your metabolism will not be optimised!
That's why i see vinegar has a true natural energy drink, which i drink with meals and while exercising, especially refreshing and revitalising on long runs, although if drinking vinegar with statins, I would reduce the statin by half, after informing your doctor, that you intend to drink vinegar too, which lowers cholesterol and other blood lipids at a faster rate when combined.
My diet is mostly all steamed, I have two steamers that deal with everything, I never eat meat, simply because my wife never buys it, she is a veggie and a bit fishy

, so I always get chicken breast and fish, my favourite greens are brussle sprouts, Broccoli and raw carrots, beetroot.
Do not forget that we humans start to lose our metabolic buring rate at 1% per year, so the older you are the less calorie intake is needed!
Pakjohn :Recently took up tennis and love it, no problems till I changed racquets recently, now have intense pain in my right elbow.
Soak the elbow in brewed rice vinegar in a small rice bowl, enough to cover the joint, then soak a lint cloth and bandage over night, it will be as good as new the next day, it will reduce the inflammation and pain!