Understanding the Difference Between Long Course and Short Course Fitness

Another summer is coming to an end. Here in New England, that means cooler temperatures, shorter days, and a feeling of transition. For many triathletes and runners, late summer also signals change. The racing season is winding down. Perhaps you are planning on ending your 2003 campaign with a bang by partaking in a long course triathlon or fall marathon. Like a farmer harvesting his crops, you hope to capitalize upon all of the hard work you’ve laid down throughout the spring and summer. So how do you ensure the success you’re looking for on the big race day? Today, I’ll talk about the art of peaking for a long course event and how you can turn what may seem like a daunting task into a simplistic approach to success.

I’ve been competing on and off as a multisport athlete for the past 8 years. Before I took the time to learn how the body responds to exercise, I was often frustrated by the fact that my short course performances paled in comparison to the results I’d produce in long course events. I won the FirmMan half Iron Triathlon both times that I entered it; first in 1996 at 20 years of age and next, in 2000, where I was able to win in a course record time of 4:05:52. Yet success on the short course scene eluded me. I struggled to keep up with the same people I’d best by up to 20 minutes in the longer events. What was going on here?!

What I had failed to understand was the following: I had two things working against my short course game. Both my VO2max (aerobic capacity or ability to produce energy aerobically), and VLamax (anaerobic capacity or ability to produce energy anaerobically) were weaker than that of my fellow triathletes. The following example will shed light on why I was losing ground.

Let’s take two athletes. Suppose that everything else being equal:

Athlete 1 has a 5k time of 15 minutes. His velocity at VO2max (V at VO2max) corresponds to roughly 4:50 per mile. He has a VO2max of 75 ml/kg/m and a VLamax of 12 mmol/l.

Athlete 2 has a 5k time of 15:30 . His velocity at VO2max (V at VO2max) corresponds to roughly 5:00 per mile. He has a VO2max of 70 ml/kg/m and a VLamax of 7 mmol/l

What does this mean? Athlete 1 is able to beat Athlete 2 by 30 seconds because he can produce energy at a faster rate both aerobically and anaerobically. A definite advantage when speed and high intensity racing is the name of the game.

So how does this example lend itself to long course preparation? Refer back to the stats on each athlete. Notice the difference in VLamax (anaerobic capacity)? Let’s talk a little bit about what this means.

Our bodies rely upon glycogen, a high octane fuel source that is stored in the muscles and liver, to produce energy. The process of breaking down glycogen to provide energy is called glycolysis. This process is referred to as “anaerobic” because it does not require oxygen. The rate of glycolysis changes in accordance to our energy requirements. As the intensity of activity increases, so does the utilization of glycogen. The maximum amount of energy that an athlete can produce anaerobically is referred to as the VLamax. A high VLamax is essential for success in “anaerobic” events that last between 10 seconds and 2 minutes and require a tremendous amount of energy to sustain high force output and speed. But how does the VLamax relate to endurance events?

Here’s where things get interesting. When glycogen is split, it provides energy for the anaerobic or “glycolytic” system, and an organic compound called “pyruvate” for the aerobic or “oxidative” system. Pyruvate is the preferred fuel of the aerobic system. It produces energy much faster than fat (another fuel for the aerobic system), but can be depleted quickly at high intensities. We’ve all heard of people “bonking” or hitting the wall at mile 20 of a marathon. When glycogen stores are exhausted, and the aerobic system isn’t provided with enough pyruvate to meet the energy requirements being imposed upon the body, it is forced to rely upon its “crude” fuel source: fat. The end result: an utter feeling of fatigue accompanied by very slow progress; you’ve simply exhausted your high octane fuel source (glycogen/pyruvate) and are running on fumes.

me running

When an endurance athlete’s VLamax is too high, the athlete has 2 major problems on his or her hands. The first problem has already been discussed: glycogen stores are exhausted prematurely and the athlete runs out of high octane fuel. The second problem has a direct effect upon the velocity which the athlete is able to maintain in long course events. We’ve already established the fact that the glycolytic system is responsible for providing the oxidative system with pyruvate. The higher the VLamax, the more glycogen the body splits at ALL intensity levels. The more glycogen the body splits, the more pyruvate delivered to the oxidative system. Any pyruvate not immediately utilized by the oxidative system for aerobic energy production will be converted into the endurance athlete’s worst enemy: lactate. Lactate is present at just about every intensity level, and as long as the concentrations remain low, performance is not compromised. However, as lactate levels increase in the working muscles, so does the concentration of hydrogen ions. It is the hydrogen ions, NOT lactate, that cause the painful, burning sensation that we experience at high intensity levels. But since hydrogen ion concentrations rise and fall in accordance to lactate levels, the two are closely associated with one another.

The point at which the body is no longer able to process Lactate at the same rate that it is being produced is called the Lactate Threshold (LT), otherwise known as the Maximum Lactate Steady State (MLSS). At velocities above LT, lactate and hydrogen ion concentrations increase steadily. The higher the sustained velocity, the higher the concentrations. The higher the concentrations, the more painful the sensation. Anyone who’s run an 800 – 1500 meter race knows what I mean. Efforts above Lactate threshold will eventually force the athlete to slow for one or more of the following reasons: the hydrogen ion concentrations impair muscle contraction, the athlete can no longer bear the pain and discomfort or glycogen stores are exhausted. Obviously, the higher the intensity, the sooner the athlete will be forced or choose to slow down.

The key to coaching long sprint, middle distance and endurance athletes is understanding how to correctly balance the anaerobic and aerobic systems. In truth, the aerobic system can never be too strong. The stronger the aerobic system, the more pyruvate the athlete can process. The more pyruvate the athlete can process, the stronger the aerobic power, or V at VO2max, will be. It is the VLamax that must be optimized to meet the needs of the athlete. As a general rule of thumb, the shorter the event, the higher the VLamax needs to be to ensure success. But course profile must also be taken into account. Even in long course races, hilly and/or windy courses will require sudden increases in power output. An athlete with a very low VLamax will have trouble attacking or powering up short, steep climbs if they’ve allowed their VLamax to drop too low. Figure out ahead of time the specifics of your course before planning out your training progression; two Marathons, though equal in distance, might require very different training strategies.

By this point we know that a lower VLamax means 2 things: glycogen sparing (increased endurance) and less lactate produced at all intensity levels. Now, whereas a sprinter or short course athlete depends upon a strong VLamax to produce a lot of energy in a short period of time, a long course athlete requires just the opposite. For runners, success in events lasting around 9 miles and above is in large part determined by the athlete’s velocity at Lactate Threshold (V at LT). The faster an athlete can run before hitting LT, the better they’ll perform in long course events.

Let’s go back and take another look at our two athletes. We’ve already established the fact that Athlete 1 is able to beat Athlete 2 in a 5k by 30 seconds. But when they line up and duke it out in a half marathon, Athlete 2 now wins by 2 minutes and 10 seconds. How is this possible you ask? The answer is simple.

Athlete 1: V at VO2max = 4:50 per mile. VO2max = 75 ml/kg/m.
VLamax = 12 mmol/l. V at LT = 5:30 per mile.
Half Marathon time = 1:12:06

Athlete 2: V at VO2max = 5:00 per mile. VO2max = 70 ml/kg/m.
VLamax = 7 mmol/l. V at LT = 5:20 per mile.
Half Marathon time = 1:09:56

Athlete 2 wins NOT because his VO2max (aerobic capacity) or VLamax (anaerobic capacity) are stronger, but because his VLamax is weaker! He can’t produce as much lactate because his anaerobic system is unable to break down glycogen as fast as Athlete 1’s. The lower lactate concentrations at all intensity levels in turn lead to a Lactate Threshold that corresponds to a higher percentage of V at VO2max.

So how do you go about training to induce a peak performance in a long course event?
A simple, but highly effective formula for success with long course racing is to maximize VO2max in the early stages of the racing season and maintain a moderate VLamax until you begin long course preparation. Your long course training program should focus upon VLamax optimization (usually reduction) through the use of Lactate Threshold, Tempo and Extensive sessions. Seek out the skilled services of a professional trainer who specializes in blood lactate testing and sport specific program design. Investing in this relatively inexpensive test will take the guess work out of your training program and allow you to hammer harder and longer than ever before.