Thanks Ian your the man!

No-  Running faster will burn more calories over a set distance than running slowly. It is just that when you keep your heart rate below 70%, a higher proportion of the calories used will come from burning fat.  Running in zone 3 will burn more calories overall, and probably more fat, than running slowly or walking.

Let say running 10 miles in zone 3 you burn 1000 calories. About 30% will come from fat = 300 calories.

Walking the same distance in zone 1 burns say 600 calories. About 40% will come from fat =  240 calories.

That's one of the things that is often misunderstood - It isn't about burning fat for weight loss in the short term.

For weight loss- calories are calories. If you take in less than you are using, you will lose weight (or rather, you will become more lean. You might put some weight on initially as a result of excercise building muscle which is denser than fat).

Heart rate training  is about conditioning your body to burn fat more readily as fuel, as your aerobic fitness improves. That in turn means you don't use your glycogen reserves too quickly, so you have them to fall back on when you need to overtake, or run up hill, or sprint finish! (or even sprint finish up a hill while overtaking!)

The good news is that once you have built a good aerobic base, if you maintain it you will be able to keep the fat off more easily. It isn't a short term weight loss solution, but it does help with the long term goal of keeping it off.

So in theory i could walk 10 miles at abrisk pace and burn more calories with zone 1 heartrate ??. than if i ran at zone 3 ?.

Thanks Ian, don't need to buy the book now :-)

Thanks Ian and Martin,made understanding this subject easier to digest and understand,have ordered book from amazon.Didnt think there was so many aspects to running and fitness,makes life more interresting!. :)

Yikes - sorry, didn't realise I had typed an essay!  Hope i didn't confuese anyone!

What Martin said is true though - it is just one method, there are many other to consider if you find HR training isn't for you.  

Hi Phillip, I have been reading a lot about this lately, after a colleague explained it to me and it suddenly made sense!

The Articles and Advice has a bit on HR training, which will enable you to calculate your zones, but knowing your zones and knowing how to use them in training are two very different things!  

Some background theory:

Your muscles work in two ways:

1) in the presence of plenty of oxygen (the aerobic system), when they burn fat as a fuel source along with some carbs, and

2) with little oxygen (the anaerobic system), where they use less fat and more carbs as fuel This system produces lactic acid, which eventually limits your performance (& causes cramp!).   

You can train both of these systems, but unfortunately not at the same time!

At lower heart rates, (60-70%, the Easy/recovery zone) your body is taking in enough oxygen to supply your muscles, and they burn fat as fuel. Over time, your muscles adapt to this, and develop an increased blood supply and more mitochondria (the bits of your cells that convert fat into energy!). This is your aerobic base. This builds endurance, and allows you to run faster and/or longer at a reduced effort. Great for longer distances.

At high heart rates (80-90%, the Tempo zone), your muscles are working in much less oxygen, and produce lactic acid. If you spend time training in this zone, your muscles get used to working in higher levels of lactic acid, so you can run at higher effort levels for longer (your "anaerobic threshold" is increased). Great for sprinting and shorter distances, and for those little bursts of speed needed in longer races to overtake your nemesis :o)

Most runners tend to run in the middle zone (70 - 80%, the Steady zone) for ALL their runs. This zone uses a bit of both systems so your cardiovascular fitness will improve, but after a while it becomes harder to improve and you tend to plateau.  

By targeting the two systems individually in your training, by running much slower for some ruins and much faster for others, you will see a better return for your training, or so the theory goes. 

The aim is to start off doing most of your runs in the Easy zone, to deveolp your aerobic base. To start off with, you will find you have to walk or run very very slowly. It is REALLY DIFFICULT, and very frustrating. And not much fun in the rain!

Over the course of a few weeks, your body adapts, and you start to get faster, all the while keeping your heart rate (and effort) in the same low zone.  You should then start to add in some tempo sessions, maybe 20 mins once a week. These are done at around your anaerobic threshold (about 85%) where it is 'comfortably hard'. Gradually, you increase the amount of tempo work, and add in speedwork such as intervals and fartlek, which are done in short bursts at around the 90% level.

All the while, you carry on your easy/recovery runs at less than 70%, alternating hard sessions with easy/recovery sessions.

A good resource is the 'Heart Rate Training for the Compleat Idiot" , currently a tenner on Amazon and worth a read. A few too many testimonials that are supposed to be motivational, but the theory is well explained and there are some trainng plans as well that you can adapt to meet your own needs. 

It is all about effort not speed - as you develop your aerobic fitness over the course of a few weeks / months, you will speed up while your heart rate stays low.

So- while it seems bizarre that slowing down can make you faster, there is some truth in it, provided it is done in combination with periods of faster and harder work.

I hope this helps and isn't too technical - it is a tricky subject to grasp (and explain!) but one that is worth reading around. 

Good luck in your running, regardless of whether you decide to persevere with HR training :o) 

Can someone explain about heart rates,as i keep reading about how important it is to train in certain heartrate zones?.i have looked back over all my walk/runs and worked out that my average hr overall the sessions equates to 138 av.hr,is this a good average to train at?.As lookig back at previous forums it seems to suggest that if your hr climbs above a certain figure you are better off walking part of the way?.as this is better way of training,i thought that ruunning/jog will be more beneficial than walking. a cofused beginner!!.