kaiser":38i6z9my said:
Try this book for starters if you decide to go for it. Or if you see it in a book shop it'll tell you all you need to know in the first few pages, the rest is just padding(authors admission).
http://www.amazon.co.uk/dp/1891369849/r ... 1891369849
The 220 minus age formulas are as outmoded as throwing witches in the water to see if they float or not.
To add to and probably complicate the 'fat burning zone' theories. You normally utilise fat as an energy source as well as glycogen(carbs). The harder you exercise the more you use, the problem being you only have a finite supply of glycogen compared to fat. Using up your glycogen will cause you to bonk.
The choices are - exercise for longer, at a lower rate - which may well be using fat as the energy source - and people miss the point and think that's significant as an advantage. It's not. Not by any tangible means.
Or, exercise at a higher intensity, for a shorter period.
Now for those who are exercising merely to lose weight / bodyfat, all that matters is how much energy is expended.
For that end, focussing on the energy source is merely a distraction. What about people on diets where they take little-to-no carbs? Ketosis happens and bodyfat is used to convert to glycogen. And guess what - when many first realised that, they though that was advantageous (from a metabolic perspective) too.
Sure, endurance athletes or people training for long periods at fairly high intensities, may well deplete glycogen to the degree that the body needs to re-adapt quite quickly, but for the normal person exercising, it's not normally an issue (all other things being equal - diet, no adverse medical conditions).
So for those that want to lose weight - the choice is largely arbitrary - choose a lower heart rate / steady state cardio type activity, but do it for longer, or choose a higher intensity (or intervals) and do it for a shorter period.
For people actually wanting some cardiovascular benefit, then it won't really be an option - you'd be pushing higher in the range, anyways, and have totally different goals.
kaiser":38i6z9my said:
Staying in the 'zone' should keep you mostly using your fat supplies and postponing the bonk. Thus exercising in the zone means you can go longer and ultimately burn more calories.
Real world, though - many people don't want to train for longer at lower intensities. For as many who like low-ish intensity, steady-state cardio (exercising in the <spit> "fat burning zone") there's people who want to show progress in their time or distance, do intervals, or actually like spinning classes.
kaiser":38i6z9my said:
You do not pass through the zone were you switch from fat to glycogen, you continue to burn fat. The heart rate monitor will allow you to train at a level were you can increase your anaerobic threshold, ie allowing you to work harder whilst utilising fat as a primary energy source. Off the top of my head you have around 3000 calories of glycogen stored in your muscles and liver but have around 30,000 calories worth of fat (average man).
And do you know how much activity and for how long you'd have to do it, in the "fat burning zone" to expend 3000 calories in one workout?
For people losing weight, best deficits are in a few hundred calories.
I'll say it before, and I'll say it again, people falling for this "fat burning zone" and clinging to it, are as mistaken as those that did the same for ketogenic diets having some metabolic advantage (they didn't, they may have other advantages, but nothing metabolic or specifically based on the fuel source).
Fat is the body's long-term energy storage. So for any you burn using exercise in particular zones, or diets that force that metabolic pathway, you're not using other energy sources, and when there's surplus, it just goes right back in storage as fat. So what really matters for loss is deficit.
After that, it's down to body composition, but in deficit that tends to be more better served on ensuring you preserve what you want to sustain, rather than focussing on what gets used for energy.
