Race-Specific Training

By Mike Arenberg

In periodization training, one of the key points is that there’s a time and place for every workout. There’s a story about Arthur Lydiard at the 1964 Olympics to illustrate this. A talented Canadian runner was watching Lydiard’s athletes run an interval workout and a day later, he decided to run the same workout himself. When asked by a reporter what Lydiard thought about the young Canadians’ workout he responded, “I think it’s the last nail in his coffin.” “But your runners ran the same workout yesterday,” the reporter replied. Lydiard responded with a sly grin, “Yeah, but my boys needed it.” Lydiard’s athletes won three Olympic medals. The Canadian? He failed to advance out of the semi-finals. Lydiard trained his runners in stages (periods), each built around a specific physiological goal. There’s a time to go easy and a time to go hard.

A reminder from the first two parts of this column is that running ability is determined by a combination of three main factors:
In the first phase (first column) of training—base training—our goal was to develop the aerobic base, as well as improve lactate threshold (Factor 1) with the introduction of tempo runs. In this 8-week, race-specific phase of training, our goal is to work on the next two factors: Vo2max and running economy (RE). While many runners and coaches think RE is a reflection of running form, it’s more influenced by those microscopic structures that influence oxygen delivery to and from muscles. Maximum oxygen uptake, or Vo2max, is a scientific measurement of the amount of oxygen your body can deliver from your heart and use in exercising muscles. Vo2max can be a pretty poor predictor of performance potential when you try to compare runners. However, your velocity at Vo2max (vVo2max) is an outstanding predictor, mainly because it combines aerobic capacity (the total amount of oxygen a runner can use) and running economy (how efficiently oxygen is used). vVo2 is the speed at which you run when you are consuming oxygen at your Vo2max.
When trying to decide what workouts to improve both Vo2 and running economy, I’m reminded of a quote by my mentor, coach Joe Vigil, who often said, “Arenberg, there are 1,000 roads to Rome.” Remember, the workouts here are one road. Other coaches may use different workouts. There are, however, some common themes to the design of these workouts.
One of the important things to consider when designing a training program is the idea of progression. In the base training phase, think of progression in terms of duration of easy runs, tempo runs and long runs. In the race-specific training phase, this idea of progression is critical when talking about intensity. The prescription of running intensity during prolonged workouts has always been an approximate endeavor because adjustments of intensity often rely on the athlete’s perception of effort. Measurements that accurately reflect the intensity of running in terms of metabolic demand, including oxygen consumption (Vo2) and blood lactate, are limited to laboratory settings. By contrast, a measurement tool such as percent of vVo2 offers us, as coaches, a reliable and objective variable with which to work.

Estimating Your vVo2max
The most accurate way to determine your vVo2max is by laboratory testing. Since that isn’t a realistic option for most of us, you can estimate your levels in one of three ways.
1. vVo2max is close to a 1-mile race pace for recreational runners and close to a 2-mile race pace (10–15 seconds per mile faster than 5K race pace) for highly trained runners.
2. 6-minute time trial: To perform this test, go to your local running track and warm up thoroughly. Then run for 6 minutes at the fastest pace you can maintain for the entire test. You can now determine your vVo2max using the following formula: distance covered in meters/360 = meters covered per second. For example, if you covered 1,600 meters in 6 minutes, then your vVo2max would be 1,600/360 = 4.44 meters per second. To convert your meters per second pace to a 400-meter pace divide 400 by meters/seconds. In this example the equation would be 400/4.44 = 90 seconds. Your pace would then be 90 seconds per 400 meters.
3. Estimate using 5K race pace: Simply subtract about 20 seconds per mile from your 5K race pace. If your current 5K pace is 6:00 per mile, your estimated vVo2max pace is around 5:40 per mile.

During this phase of training we’re introducing harder-paced efforts with limited rest, run at specific individual intensities. When planning your individual workouts, important questions need to be addressed: How long a run? How many runs? How often? How much rest? At what intensity? The three most important questions are: At what intensity? How to determine that intensity? How much rest?

How Long? (How long an interval to run?)
Research tells us, for a period of intermittent exercise that approximates a max Vo2 workload to overload the cardiovascular system effectively, it needs to be of at least 2 minutes’ duration due to (a) lag time in the cardiovascular response and (b) the oxygen-buffering effect of myoglobin. It’s been shown that doing interval runs between 2–5 minutes maximizes training benefits to Vo2. This correlates to distances between 600 meters to 1 mile.

How Many?
This depends on the length of the interval. One Vo2max workout was developed by Veronique Billat at the University of Lille in France. Billat found that training benefits are maximized by doing 5x3-minute repeats at your vVo2max pace with 3 minutes of recovery between the repeats. 15 to 24 minutes of accumulated interval time is appropriate for most when performing intervals in the 2–3 minute range; 24 to 32 when performing the 4–5 minute intervals. There is little or no benefit from longer sessions.

What Intensity?
Running repeats at or near 94–100% vVO2 will be sufficient to elicit the desired adaptations. Interval training above 100% Vo2max won’t provide additional stimulus for improving maximal aerobic capacity, or lactate threshold, and may hurt. At intensities above 100%, the stimulus for improving maximal oxygen consumption is actually reduced, due to dramatically decreased training volume, and the inhibiting effect of lactic acidosis on cellular oxygen utilization. Different coaches will prescribe different intensities.

How Much Rest?
Many coaches subscribe to the idea that rest period should correlate to workload. If you were running a 5-minute interval, you would take 5 minutes’ rest. Rest periods more than 3–3½ minutes are less effective in developing key physiological responses. With a shorter rest period you start the next run with slightly elevated heart rate and blood lactate levels. Remember: Our goal is to improve Vo2. This is accomplished by increasing cardiac output (amount of blood pumped by the heart per minute). The major reason for an increase in exercise capacity with a training program is the rise in the maximal cardiac output. It plays a bigger role in increasing maximal exercise performance than does the increase in oxygen uptake and utilization by the skeletal muscle cells. Since our maximal heart rate doesn’t change—and may even be lower—following exercise training, this increase in cardiac output is the result of a higher stroke volume (amount of blood pumped per heartbeat). Cardiac output = stroke volume x heart rate. This increase in stroke volume is a result of both an enlargement of the left ventricle muscle, as well as an enhancement of the heart’s contractile capability. How does this work (specifically regarding shorter rest periods)?
During an interval, heart rate climbs high, then at the moment you stop the interval, heart rate immediately starts to drop, but venous return remains high. These repeated exposures to ventricular stretching may help trigger ventricular remodeling (bigger ventricle volume). Interval training with appropriate rest periods allows us to accumulate a greater volume of stress on the blood-pumping capacity of the heart. By doing so we promote maximal stroke volume responses and, in turn, increase cardiac output.
Sample workouts to boost your Vo2max: These workouts can be done on a measured loop, or track, or done by minutes’ run.
1. 3–4x1,200 meters (or 4–5 min.) @ 94% vVo2max with 3 min. recovery
2. 4–5x1,000 meters (or 3–4 min.) @ 94–96% vVo2max with 2–3 min. recovery
3. 5–6x800 meters (or 3 min.) @ 96–98% vVo2max with 2–3 min. recovery

How Often?
Workouts like this are demanding and require more recovery time. I don’t recommend more than one per week. This can be done throughout (and beyond) the 8–10 week race-specific cycle of training. During this race-specific cycle, tempo runs are maintained, as is the build-up of a weekly long run.
Understanding not only how to plan your training cycle, but also the physiology involved, will help you train more efficiently. Planning a training program is much like following a recipe. Adding the right amount of ingredients at the right moment will bring about the ideal end result. At this point in the planning, it’s time to add some intervals and enjoy the end result: better racing and personnel bests.
— Coach Arenberg

Coach Michael Arenberg has an M.B.S. in exercise physiology from the University of Colorado. He has been a competitive distance runner and triathlete for 39 years, completing 28 marathons and 15 Ironman triathlons, including 3 times qualifying for the Ironman World Championships. He has coached U.S. men’s and women’s Olympic Trial qualifiers in the marathon and two top-10 finishers in the U.S. Men’s Marathon Championships, as well as multiple Ironman World Championship qualifiers.
Coach Arenberg is available for coaching and can be contacted at makona94@aol.com
If you have a training question for Coach Mike, send him an e-mail at the above address. While he is unable to personally respond to every question, answers will appear from time to time in upcoming issues of Missouri Runner and Triathlete.