ECONOMY: Economy in endurance sport is a measure of how much energy it takes to maintain a certain pace. Obviously if race day speed is your goal, the less energy it takes to hold a distinct pace the better. If you continue to improve your economy throughout a season, you should be faster in each subsequent race of the same distance with the same total energy output.

I encourage athletes to measure their economy during certain phases of their training to assess fitness gains (or losses—which is very, very rare). If you’ve been involved in endurance sport for a while you may have heard of the MAF (maximum aerobic function) test. This test was originally developed by exercise physiologist Phil Maffetone.

The traditional MAF test is done on a track for consistency of conditions; the athlete being tested runs at an exact heart rate for a set distance. The test is repeated as the season progresses. As the athlete moves through his/her base-building training—if all goes as planned—the athlete goes faster at the same HR with each subsequent test. If the athlete doesn’t go faster with each subsequent test, there’s either a physiological problem, or the athlete has plateaued to peak fitness levels for the amount of training time completed per week. The difference between elite athletes and the majority (us), is that they're more efficient at processing oxygen (generally higher max VO2 values because of age or genetic 'talent').

You can't alter your genetic potential for endurance sports, and we're not all created as equals in this regard. So the best measure of progress is comparing you to the former less well trained you. Effort is the best measure of success, and the wise athlete only competes against himself. Enough of my lecturing...

Keep in mind that form counts, so economy gains can come not only from improved cardiopulmonary fitness, but also efficiency of movement. Generally, form improves with repetition, but not always. For example: optimal swim form is so different than any other movement we normally use in our lives that time dedicated to form work is as important as the consistency of your timed swim sets. Bike and run form can become more efficient with form work as well.

For endurance athletes, improvements of economy are absolutely the best measure of fitness gained. If you can hold a 7:30-minute per mile pace at a HR of 145...where during the last test you could only maintain a 8:00 pace, you’ve had substantial improvement of aerobic efficiency! Keep in mind that improvements of economy for athletes new to endurance sports will be greater than for those training for many years, who've already developed their potential to a great degree.

I recommend a slightly different economy test which I describe as the ‘real world’ MAF test. The difference is that I ask the athlete to find a 5-mile to 10k route on roads and/or trails with hills—and whatever else you might encounter in the 'real world' on race days. The course needs to be one you can exactly repeat each time you test yourself, with distinct points to start and stop your watch. In fact this workout is probably not much different than a regular run day, except that you’re very focused on the HRM, holding a certain pre-determined HR as accurately as you can.

This real world aerobic economy test works best for runs, but it can also be done on the bike with timed efforts over a set course. I've always found my HR on the bike to be more varied from day-to-day than for runs, so for me the run test is a more accurate assessment. On the bike I'll typically observe a lower HR with the same time, rather than a faster time at the same HR. Your experience may vary.

To assess swim economy I prefer a standardized set you can repeat periodically. For example: 16x100 yards restarting on a set interval for Olympic distance focused athletes work well. My HRM doesn't work in the pool, and I wouldn't have time to look at it during a set anyway, so I do all swim tests by distance and time.

Improvement on economy assessment training days can be very satisfying and build confidence. Choose a set course and test yourself during the off-season when fitness isn't at peak levels. Then compare your pace at the same heart rate, on the same course in-season, and take satisfaction in creating the new fitter you.