All of the standard distance races including cross country are combined zone races. Combined zone means that energy needed for muscular contractions at race pace is derived from both the aerobic and anaerobic energy systems in combination. Improvement in both the capacity and efficiency of these independent energy systems, and how they work in tandem, is the reason distance runners train.
The anaerobic system is improved with maximum, and near maximum velocity work. Gains in the system are made through neural improvement at the neuro-muscular junction, improved neuron-muscular biomechanics during maximum effort, and muscle cell changes that allow for greater drainage and tolerance of lactate and hydrogen ions. The energy contribution of the anaerobic system varies from 50% in the 800 meters to about 8% in the 5000 meters. The training emphasis of the anaerobic energy system is dictated by the preferred race distance of the athlete.
The aerobic energy system contributes more than 50% of the energy needed to run a distance race at maximum race pace. The characteristics of the race distance will dictate the amount of aerobic training emphasis. Aerobic energy system development is centered on the physiological concept of aerobic power or what is commonly known as VO2 max velocity.
Aerobic power is simply the amount of oxygen that can be used by the working muscles of an organism over a prescribed time at full aerobic effort. The work time measured is generally between 5-10 minutes whether on a treadmill in the lab or out on the workout course. The results are then standardized as a per minute value of oxygen usage per kilogram of body weight. That way data can be compared from animal to animal or human to human.
Since both the lab test and field test have both a time and distance component, then velocity at maximum aerobic power effort can also be calculated. Improvement by the distance runner in training of this aerobic power velocity value translates to faster times in every race distance because aerobic power is a known fractional characteristic of all distance races (Table 1.)
Using VO2 max as the index value, it is logical that as that value improves with training so do the linked fractional unit percentages at the other race distances. Using Table 1 data, one can determine that the race distance most associated with maximum aerobic power is the 3200 meter run.
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As fitness improves the percentage values shown do not change but the associated velocity at each distance will improve. As an example, at the start of the year a runner can run 11:00 for 3200 meters to exhaustion, or about 5:30 pace. The projected mark for the 1600 meters based on Table 1 should be 4:55. This index value is their current velocity at VO2 max, but as the season moves on so does the 3200 meter mark.
Soon the athlete can run 10:30 or 5:15 pace for 3200 meters. Again referring to Table 1, the projected mile velocity at this new time should now be 4:41. The same velocity changes should occur for every race distance shown. The key in aerobic training is in improving the aerobic power value since that is the index value that physiologists have shown to be a key mark in aerobic fitness.
Running economy, which is the efficiency that the distance runner uses food energy and oxygen in movement, is dependent on aerobic power because economy is heavily dependent on greater blood flow to the muscles.
Running economy improves with VO2 max training as does lactate threshold velocity. Improving aerobic power means developing a bigger heart, greater stroke volume, increased capillary beds, increases in mitochondria and enzymes. All of these are linked to improved running economy.
The most effective way to train to improve aerobic power is to train right at present day VO2 max velocity, Date pace 3200 meter velocity divided into interval training sessions of 800, 1000, or 1600 meter distances.
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The total workout volume should be between 5500 and 6500 meters. Recovery time is equal to work time during the session. These types of workouts should be done about once per week for the entire season.
Physiologists have given coaches considerable information on the concept of aerobic power. Scientific evidence shows that all aerobic races are shaped by aerobic power and its development both before and after the runner reaches genetic maturity. It is important these principles are applied to developing distance runners.
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FREE REPORT From Distance Expert Scott Christensen
Race Strategy and Tactics for the Endurance Events: 800m – 5000m
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