The Lactic Enemy

Let me tell you about aerobic base training.

We have a nice little thread going on the Runner's World website

To fully understand the methods involved you'll need to read the article referenced on the second posting: Hadd's approach to distance training . Warning! It's good but it'll take at least 30mins to read it!

I will try then to summarise what base training is about. By all means send me comments (you can post on the Runner's World Base Training thread above). There may be inaccuracies that I'd want to correct. I am not an expert, but rather an enthusiastic amateur. I am just summarising what has been discussed in the various articles and threads. Hopefully I can give a flavour of what base training is about, and also to get to understand it better myself.

So taking a deep breath, here goes!

We have 3 basic energy systems (I believe there is a fourth, but this is a summary!)
Anaerobic
Aerobic
Fat burning

Dealing with the anaerobic system first, this is the one sprinters use. You know when you are anaerobic because you can 'feel the burn'. That dead weight burning sensation? That's the lactic acid accumulating in your legs. You are good for short bursts of this but you can't keep going for long at this rate. It's characterised by fast paces and high heart rates. Training of the anaerobic system is all about running fast repetitions. "To run fast, you train fast" is something you'll often hear (but read on - that one is a definite no-no!).

Your aerobic system, by contrast, is far more energy efficient: some 13 times more, apparently. This is the critical one for us base trainers. Even in distances as low as 1500m you are relying on 80% of your energy to be supplied by your aerobic system. As the distance increases, you rely even more on your aerobic system. At moderate paces and heart rates, you are in your aerobic zone, with lactic acid production under control. As pace increases you start to borrow from your anaerobic system. There isn't a sudden switch from one system to another, but there is a notion of an 'aerobic threshold' below which you are mostly relying on your aerobic system, and an 'anaerobic threshold' above which you are relying mostly on your anaerobic system. These thresholds correspond to particular heart rates, different in each individual unfortunately, but it is these heart rates which you will hear 'base trainers' referring to all the time.

A word on fat burning. You will hear talk of a 'fat burning zone' in some circles. Personal trainers seem to love this one. A heart rate below which you are burning fat. The slimmers dream! While it is true that at lower heart rates fat burning is a more significant energy system, again, it doesn't simply switch in below some magical threshold - it is simply more critical at slower paces. In fact marathon runners rely on it - without it you would run out of your aerobic fuel, glycogen, and hit the dreaded wall. And don't worry about being too thin and not having enough fat (if only!). Fat burning is a highly efficient energy mechanism, you don't need much of it! Hooray! Training of your fat burning system is characterised by long slow runs at low heart rates.

So the wisdom is, that if your anaerobic system only contributes a small amount to distance running, then only when you have squeezed the very last drop out of the other mechanisms do you really need to then concentrate on the anaerobic system. So that's what aerobic base training is about - getting our aerobic system (and to a large extent fat burning) to the best it can be, before working on the anaerobic side.

And there's a catch! (There always is, isn't there?!) Unfortunately you train your anaerobic system to the detriment of your aerobic system. Anaerobic running creates lactic acid which is very bad for your aerobic system. For every bit of anaerobic training done, you must do far far more training of your aerobic system to compensate. So for us base trainers, we like to keep the training strictly aerobic, in order to maximise its benefits. No speed sessions! All this is probably a bit alien to you club runners out there, so let me point you at an excellent piece by Ingrid Kristiansen.

So what are the main characteristics of an aerobic base training schedule?
Typically:
Daily running at slow paces, typically 70% of maximum heart rate. Build up slowly and try to get to doing an hour a day of running before moving on.
Patience is the key. Don't rush this. Set aside at least 6 months to build up the running.
No speed work! Keep racing to a minimum.
Once at an hour a day, some work sessions can be introduced, gradually, usually no more than 2 per week at slightly higher heart rates, but still aerobic, less than 80-83% of maximum heart rate.
A weekly long run can be gradually built up but keep it slow, <70% , but keep to less than 2 hours of running.

There is much debate about how you determine your maximum heart rate, which is unfortunate because it is quite important to know what it is! If you estimate a figure that is too high, then you run the risk of reducing the effectiveness of work sessions because they are at too high a rate, and worse, of injuring yourself because your slow runs aren't allowing you to recover properly.

John L Parker in his book 'Heart Monitor Training for the Compleat Idiot' (sic) suggests a formula of 205-age/2 as the most accurate for us athletes. Better, is to do a max HR test. Hadd suggests a method in his article (See link above) involving warming up, running 800m as fast as you can, short recovery, then running 400m as fast as you can and reading your heart rate at the end. Another method is to do 5 200m hill reps, pushing harder each time, until going flat out up the final one. Whichever method you use, it is important to get an accurate measure of maximum heart rate.

Typically, your daily easy runs will then be at 70% of maximum. The major comment from base training newbies is "This is way too slow - I have to walk to keep my heart rate down" If this is the case then maybe run a little quicker for the first couple of weeks. Eventually though you will find it easy to keep it slow and you will see your slow pace improving quite quickly!

I won't talk about work sessions at this stage - maybe a later post - in fact I'm a little new to them myself! If you are new to this, then you really shouldn't be doing work sessions anyway but trying to get your running to an hour a day at slow paces.

There will be more to come, including some personal remarks on how my training is progressing, and how I've interpretted all this. There may be inaccuracies in the above, in which case please correct me! Please don't shoot the messenger!

Happy training!