Aerobic Base Training: Do your homework

If it’s fall and you are preparing to race next Spring, it’s time to be working on your base. Quoting the old cliché, it is time to lay a big foundation for the harder training and racing in the months ahead, and the bigger the base, the bigger the structure that can be supported.

What is aerobic base training and why is it so important? Base miles are the way to develop aerobic power. Bike racers usually get dropped while riding as hard as they can, so shouldn’t we work on riding as hard as we can? The answer is ‘no’, at least not now. Consider a race pack. At the front trade-team riders chat about their cars and their travel plans. In the middle  riders are beginning to suffer. At the back are riders, probably on bikes as fancy or fancier than those at the front, gasping for breath and barely hanging on. What’s the difference between these riders. Why will the leaders be able to speed up when they decide to make the race while the tail-gunners are maxed out already? There may be differences in efficiency or aerodynamic drag, but the main difference is aerobic power. The leaders have done their homework and are still riding comfortably below their lactate thresholds. The unfortunates at the back are at or above theirs.

Before working on going as hard as you can, work on going faster without going hard. To achieve that, do loads of steady-pace base miles. This is what used to be called “Long Slow Distance” or “LSD”, but that was really a misnomer. During the first few weeks, base riding is pretty slow and hill climbing may be impossible, but if you do a good job you’ll be making good time on the flats and spinning up the hills at a base pace after a couple of months.

How do you do build base? You do a large volume of endurance-paced rides, with little energy invested in anything harder for several months. Some coaches allow a few harder rides, but I don’t recommend them. Steady efforts of several hours at a controlled heart rate do the most for aerobic development. A few years back Wenzel Coaching had a long-time client picked up by one of the top professional teams in the world based on race results achieved after doing several months of base riding and exactly one sprint at a higher pace.

We define the “endurance zone” to be 69-80% of maximum heart rate and the “low endurance/recovery zone” to be 59-70% of maximum heart rate. It is possible to define zones based on power, but they must be corrected almost weekly early in the base period when aerobic power is increasing rapidly. It is probably not important for training zones to be “correct” to the nearest heart-beat. Different coaches use different percentages and still get good results for their clients. Doing a lot of time in zones much higher than the ones I’ve recommended will exhaust most riders before they’ve done enough miles to have competitive fitness.

How much base riding is enough? More is usually better, so long as you are staying fresh, strong and enthusiastic, but not everyone needs to fill all his or her available time with base riding. The needed volume depends on goals, experience, geographic region and talent. Being competitive in the beginner categories probably requires about 7-12 hours per week for several months. Being competitive at the elite-National level probably requires 15-25 hours per week for many months. This does not mean that a beginner who rides 20-hour weeks will become an elite rider. More likely, he or she will drop from exhaustion. Rather than have a fixed target volume, use feedback from your body to decide how much to do. If you have a good day, ride in the endurance zone. When you begin to tire, back off to the recovery zone and go home. If you have any more trouble raising your heart rate on a given day than on a good day, use the recovery zone for the whole ride. If you need more than a couple of recovery days per week in several consecutive weeks, you are trying to do too much and should cut back your mileage goals, reduce your training pace, or cut some other stress out of your life.

This last rule, train at recovery pace unless you feel energetic, is the hardest rule to follow for many training-obsessed riders, yet my experience with hundreds of riders is that accepting this rule is key to making the transition to the elite ranks.

To calculate your endurance zone you need to know your maximum heart rate. I’ll suggest a test here. Do not attempt it unless you have been riding regularly including hard efforts, are in good health, are not obese and do not have a history of heart or cardiovascular disease or diabetes. The results will only be valid if you are well rested, fed and hydrated, if you have not been ill in the three weeks before the test and if it is not too hot or too cold.

Maximum test: Do this test on the road because few riders get their heart rates as high on a trainer as they do outdoors. Running maximum heart rate is different from riding for most people, so test on a bike. Warm up with at least 1/2 hour of easy riding and then several jumps long enough to get your breathing up. Recover and then ride up a gradual hill for a couple of minutes at a pace that just raises your breathing. Now accelerate hard and hold the highest speed you can. When you think you can’t go any more, sprint. When you think you can’t sprint any more, sprint again. Keep pushing. You know you’ve got a good maximum if your heart rate begins to drop even though you maintain a maximal effort. The highest number you see is your maximum, unless you’ve seen a higher heart rate in the past few months, in which case you should use that higher number instead.

You may be thinking that this maximum test sounds painful. Why not calculate your maximum from a formula? Most likely you’ve heard that maximum heart rate = (220-Age). That’s mathematical, easy to calculate and pretty scientific sounding, but very often wrong. The only valid way to calculate heart rate training zones for an individual athlete is to do your own testing. Incidentally, one advantage of training by power is that no one is suggesting that you can set up power training zones except by testing yourself.

How bad is “220 minus age” as an estimate of maximum heart rate? Check out the graph below of maximum cycling heart rate versus age for 138 clients of Wenzel Coaching. The majority of these are well trained racing cyclists. As you can see they range in age from 15 to 67. They include both men and women and all competitive levels from cat-5 beginners to professional riders and national champions.

The dark line is a “best fit” line. It goes approximately through the average maximum heart rate for each age. If 220-age were right on average the maximum hearts rates at 20 and 50 years old would be 200 and 170 respectively. This looks about right for the 20-year-olds. But for the older riders the average is closer to 185 than 170. This is consistent with maximum heart rate = 210 – age/2, rather than 220 – age.

The trend line is very close to 210 – age/2 for all ages. The reason that 220 – age gets more play than 210 – age/2 has more to do with the trouble the public has with fractions than with actual maximum heart rates.

Now note the huge spread. This is what makes the formula useless. The trend line goes through very few of the points. The majority of the points are at least a few beats off the line, and many are off by 15 beats or more. For 30 year-olds we have maximum heart rates from 177 to 212, or 220 – 43 to 220 – 8. Even with the “better” formula, which predicts a maximum heart rate of 210-30/2=195, we’re still way off for the majority of riders. The actual values for a 30 year-old vary from 210 – 33 (predicted max for a 66 year-old) to 210 + 2 (predicted max for a child who won’t be born for four more years).

If you use 220 – age, or 210 – age/2 to calculate training zones, you may well be off by enough to make you train too hard and end up over-trained. Setting the zone too low is less of a problem physiologically, but makes training unnecessarily boring.

The bottom line is, do your base miles but don’t use age-based formulas to predict maximum heart rate. These formulas may be useful to health and fitness workers who are reluctant to let their clients do any maximal exercise for fear of having the client drop dead from a heart attack or stroke, but they are useless for athletes who are serious about their training and fitness. Do you own testing and then do your base miles and note the results. I think you’ll be pleased.