This is a very popular question during the winter, as people gear up for the coming year. High school runners are between cross-country and track seasons and are wondering what the most effective way would be to improve their times for the spring track season. The rest of us are waiting for spring and summer track, road racing, cross-country, basically pick your poison. We are all looking for the same thing. What can we do during our non-competition months to best prepare ourselves to rewrite our personal record books when the next racing season comes around?

The answer for us all is simple and easy if you are willing to do the training. The off-season is the time to establish your aerobic base. Why would this be such a simple answer? Why would it work for the high school middle distance runner as well as the veteran marathoner? Simple: everything starts from an aerobic base, an aerobic base takes time to properly established, it can be maintained during your racing season fairly easily once established, and continually and repeatedly building your base stronger during the off-season is the most effective way to gain long term improvements.

Why is an aerobic base so important? For long distance runners, the answer is actually pretty obvious. For races of 5k and up, the race itself is nearly all aerobic. In a 5k race, about 85% of the energy your body will burn will be burned through aerobic processes. Only 15% of the energy you burn, give or take, will actually come from anaerobic processes. Even for races of as short as 800 meters, the race has a meaningful aerobic component. Aerobic training offers many benefits along this line, such as increasing the number of capillaries, the smallest of blood vessels which go through your muscles and directly deliver oxygen to your muscles for energy production, in your working muscles; increasing the number and size of mitochondria, the aerobic power plants of the muscle, within your working muscles; and increasing your body's ability to burn fat at higher rates, meaning you save your less readily available glycogen for when you really need it. The last one may not be of high importance for races of shorter distances but can have positive effects across the board. On top of that, building a strong aerobic base will allow you to get more out of your harder workouts you will be doing later with less risk of injury. The better the base you get in, the stronger your muscles, bones, and connective tissue will be, increasing your body's ability to handle the punishment of hard workouts as well as its ability to avoid injury. On top of that, your body will be working from a higher level of fitness, allowing it to work harder, get more improvement from each workout, and recover more quickly and completely between workouts which means you can get in more workouts.

How do you establish a good aerobic base? It's actually one of the easiest parts of distance running training. All you do is get out and run easy. How far? As far as you can go and still be able to run tomorrow. How fast? Go by how you feel. Sometimes, that may mean fairly fast. Other times, maybe it means quite slow. In fact, leave your watch at home and just enjoy the scenery if that's what you want to do. According to Arthur Lydiard, there is no such thing as too slow for these runs, only too fast. I'm not totally sold on that but I do believe most people, myself included, come much closer to too fast than too slow. How frequently? The more the better. Once a day every day is great. Twice a day is even better. Many of the best runners do 13 runs a week. That's twice a day 6 days a week with a long run once a week. Of course, gradually build the number of runs you do. Don't go straight from 4 runs a week to 13 runs a week without giving your body time to adapt. How long should you do this for? Ideally, as long as you can. The longer, the better. I would say a good guideline for minimum in most situations would be 2 months for distances that would be standard track and field distances, 3 months for longer distances such as the marathon. Why so long? Well, it takes time to establish a good aerobic base. Aerobic fitness takes time to build, it's not something that can be gained as quickly as anaerobic fitness.

Fortunately, aerobic fitness also won't be lost as quickly as anaerobic fitness. Maintaining it during your racing season and your preparations for your peak race isn't too hard. With a good base built, it can also be easier than if you don't have a good base. All you have to do is cover some distance on the days between your hard workouts and once every week or two get in a long run. Again, the same rules apply as when building the base with one little twist. Remember that you have to be well rested for your workouts. Still, pace doesn't matter on these runs. Just cover the distance, which is the most important aspect. What does matter is making sure you are adequately rested for your workouts. That may mean not running quite as far and backing off the pace some. How frequently you run also may or may not change. Some people will still do 13 runs a week, others will remove some of the 2 a day workouts and some even feel the need to take occasional days off. Experiment to find what works best for you.

Building a base is a very simple but very important and frequently overlooked part of training for all distance runners. Many runners seem to be totally focused on intervals, intervals, and more intervals then wonder why their times stagnate after a while. The answer is simple. Intervals are important for reaching your highest level of performance on race day but they will only take you so far. You need to take a look at the whole picture and a large part of the picture for any distance runner should be building an adequate base to support the later high intensity training that will take you to your peak. As my cross-country coach when I was in in high school said, running is like building a pyramid. The larger the base, the higher the peak.

Some great sources on base training (these will open in a new browser window):
Summer of Malmo (discussing summer training for high school and collegiate runners but works for any base training, I frequently do my revised version as a "Winter of Hillrunner")
Lydiard Training Guide