Running Science

by Owen Anderson

  Explosive Strength Workout

  There has been little research concerning the effects of specific explosive drills on improving maximal running speed, but this workout contains a variety of running-specific, explosive movements that should be beneficial. Many of the drills in this session are similar to those used in the Rusko, Paavolainen, and Nummela hallmark study2 on explosive training, maximal-speed improvement, and 5K performance. (The techniques for many of the drills in this workout are described in detail in chapter 23.)

  At least initially, make sure that all activities that enhance explosiveness are completed on a forgiving surface (e.g., soft dirt, grass, cushioned artificial turf, compliant track, or wooden gym floor). The session should be conducted twice a week during periods of training that emphasize maximal-speed development.

  Warm-up. Run easily for 12 minutes.

  Perform warm-up drills, including toe walking (chapter 23), heel walking (chapter 23), leg swings, skips, jumps, hops, and 60-meter stride-outs (relaxed yet fast running with a high cadence).

  Run easily for 2 or 3 additional minutes.

  Intense running for 1 minute, counting the number of times the foot on one side hits the ground. Count the number of foot strikes on the other foot, if you prefer, but do not count both feet.

  If the number of foot strikes is fewer than 90, rest for a moment and repeat two more times, attempting to increase stride rate to at least 90 on each occasion. If your stride rate is 90 or more, move on to step 3. If you don’t rech 90, continue to work on this in future sessions.

  Enhance this drill by using an electronic metronome. Set the metronome at 90 to 95 and make sure your right or left foot strikes the ground with the beeping. Relax and settle into a rhythm that is fast but smooth. Repeat this drill throughout each training week, making sure your stride rate is at 90 or above even during easy workouts. Use a midfoot strike pattern at all times.

  Skipping on the balls of the feet for 30 seconds (chapter 23): Rest for a moment, and then repeat. Use quick leg action.

  Keep the feet on the ground for a minimal amount of time.

  Spring jogging (chapter 23). Spring jog for 1 minute, then regular jog for 10 seconds.

  Spring jog alternating three consecutive contacts with one foot with three contacts with the other foot for 20 meters, then regular jog for 10 seconds.

  Spring jog on one foot for 20 meters and then on the other foot for 20 meters.

  Two-leg hurdle hop (chapter 23): Complete five passes over 8 hurdles. Set the hurdles 45 inches (1.1 m) apart and set the hurdle height at 6 inches (15 cm); progressively increase the height to 18 inches (46 cm) over time as coordination and leaping ability improve.

  Once two-leg hurdle hops are handled successfully, change this drill to one-leg hurdle hops with the reps carried out first on one leg and then on the other. Begin with 6-inch hurdles.

  Complete 6 passes of one-leg hurdle hops on each leg.

  One-leg hop in place (chapter 23): Complete 2 sets of 40 each on each leg.

  Diagonal hop (chapter 23) for 45 seconds, rest for 15 seconds, and then diagonal hop for 45 more seconds.

  Greyhound run: Complete 6 on an inclined surface (similar to the greyhound run described in chapter 23). Use an area that 100 meters of unobstructed, smooth inclined surface; a slope of about 5 to 6 degrees is best. On the downward slope, accelerate downhill for 20 meters, hold the pace close to maximal speed pace for 60 meters, and then decelerate for 20 meters.

  Rest for several seconds by walking around; repeat the high-speed running in the opposite direction back up the slight slope.

  Complete 6 reps, 3 down and 3 up. Cautiously increase the number of reps over time.

  One-leg squat with lateral hops (chapter 23): Perform 2 × 12 on each leg with a 1-minute break between sets.

  High-knee explosion (chapter 23): Complete 15, rest for a few seconds, and repeat. Progress with this exercise to eventually perform high-knee explosions on one leg at a time.

  Shane’s In-Place Acceleration (SIPA) (chapter 23): Perform 3 × 20 seconds.

  Cool-down: about 2 miles (3.2 km) of light running.

  Conclusion

  As an endurance runner, even a marathon runner, don’t enhance your maximal running speed just to improve your finishing kick even though upswings in maximal speed will spike your kick; rather, upgrade your maximal running speed to be a better distance runner. Maximal running speed is a strong predictor of endurance performance and needs to be systematically developed. Maximal speed can’t be reached after 6 weeks of training that is faster than usual; thus, work toward maximal speed throughout the year. Explosive training, fast running on slight downhills and uphills, and running-specific strength training combined with quality running should all propel maximal running speed upward.

  Chapter 29

  Promoting Resistance to Fatigue

  In order to understand which training techniques are best for promoting improved resistance to fatigue during running, it is first necessary to review some points from chapter 12. As explained in that chapter, athletes often become fatigued while running before they reach maximal rates of oxygen consumption, topmost heart rates, or highest levels of blood lactate. Thus, fatigue during running cannot be well explained by oxygen limitation, cardiac limitation, or excessive lactic acid. A more logical explanation is that there are neural-output settings in a runner’s brain that do not permit specific intensities, or speeds, of running to be continued beyond fixed durations. Neural output consists of the motor signals sent to the muscles by the brain and spinal cord during running. These signals control the magnitude of muscular force production and the rate at which the force is applied—and thus control running velocity.

  A competing view is that loss of muscle function during running is the main cause of fatigue, with the nervous system simply toning down neural output as the muscles begin to lose the ability to generate propulsive force. This is an attractive hypothesis, but it fails to explain a key aspect of competitive running: Runners with similar levels of cardiovascular function, O2max, and lactate-threshold speed often begin races at different speeds before loss of muscle function can occur. The best explanation for this situation is that neural output has been preset for each runner at the beginning of the race and is then simply maintained or gradually diminished as the race proceeds. Those runners with the highest settings, that is, those who can sustain the highest levels of neural output during the competition, are the top finishers.

  The neural-output theory also best explains the surge that takes place during the last work interval in endurance training, or the phenomenon in which endurance runners become fatigued and gradually slow down over the course of an extended interval workout but then magically burn the last work interval at the fastest pace for the entire session. If the fatigue in such sessions were truly the result of a crisis in the muscles as discussed in chapter 12, it would be impossible for the last work interval to be the highest-quality segment of the workout. A better explanation is that neural output is carefully controlled over the course of an intense session in order to minimize potential physiological problems—and then raised to a high level during a safe final work interval. It’s safe because of its relatively short duration and the impending end of the workout.

  Trainability of Neural Output

  If neural output governs competitive and quality workout velocities, then there must be a control center in the nervous system, a center that might aptly be called the neural governor. As outlined in chapter 12, there is strong evidence that this neural governor actually creates fatigue during intense or very prolonged running and attempts to limit performances. Fortunately, there is also evidence that the neural governor responds to training. That is, runners can train in certain ways in order to set their governors to allow quicker paces during their races.

  The strategy of carrying out long runs at submaximal paces is not a good approach for increasing the neural governor’s set point—unless one is preparing for an
ultramarathon—since such workouts correspond with submaximal neural outputs. A general rule in exercise physiology is that a well-trained system must be stressed at its limits in order to produce adaptation. Calling on the nervous system to produce minimal levels of neural output is thus unlikely to reset the neural governor to a higher intensity of running although it might somewhat dampen the governor’s tendency to create fatigue during very long efforts.

  Strength-training research reveals that high-intensity, explosive strength training augments neural output more than other forms of strengthening.1, 2 This is not surprising since explosive training calls for high levels of neural output, and thus the specific, desired result is being rehearsed in training, perhaps teaching the nervous system that high levels of output are safe and manageable.

  For runners, it seems certain that intense, high-quality running would enhance neural output to a greater extent than submaximal effort because fast running speeds are closer to the limit of the nervous system’s ability to regulate running. Not surprisingly, explosive training—the combination of high-velocity sprints and explosive drills and exercises—has been demonstrated in a number of different scientific studies to enhance endurance performance.2 It is possible that such training makes high-speed running more permissible and manageable to the neural governor.

  Methods for Improving Resistance to Fatigue

  Research concerning the promotion of resistance to fatigue is still in its infancy, but scientific explorations suggest that there are several ways for runners to improve their ability to resist fatigue. Conducting workouts at race velocities, modifying recovery durations during interval sessions, enhancing muscle’s oxidative capacity and upgrading lactate-threshold velocity, and engaging in running-specific strength training all appear to be viable strategies for optimizing resistance to fatigue. Even nutritional tactics can be beneficial: Avoiding hypoglycemia, maximizing glycogen repletion, and taking specific supplements have all been linked with greater contravention of fatigue.

  Extending Training at Race Speed

  Extended periods of training at a specific running velocity hike resistance to fatigue at that specified speed. For one thing, such running enhances economy at the chosen velocity (chapter 25). It is clear that confidence in the ability to manage a particular pace will also increase as that tempo is practiced relentlessly. Another effect should be that the neural governor will accept the selected, well-rehearsed speed as one that can be maintained for a more extended period of time. When a runner is preparing for an important 10K, therefore, frequent running at goal 10K pace should promote greater resistance to fatigue at 10K tempo especially if the 10K work intervals are fairly lengthy. Intervals of 2,000 meters (1.24 mi) should function more effectively than 800-meter intervals, for example, because the former teach the governor that goal 10K pace can be handled continuously over relatively long periods. Shortening the recovery periods between the 2,000-meter (1.24 mi) intervals should be an effective strategy for promoting resistance to fatigue, too, because doing so begins to simulate actual race conditions more closely.

  Adjusting Recovery Times

  Resistance to fatigue is important in training as well as racing. High levels of resistance to fatigue during training sessions permit challenging sessions to be completed at target paces, providing an optimal stimulus for physiological adaptation, especially neuromuscular optimization. When high-quality interval workouts are carried out during the initial stages of training, increasing recovery intervals can thwart fatigue and thus upgrade the capacity to hit target speeds during work intervals.3

  However, expanding recovery intervals simultaneously makes a training session less specific to competitive situations, and there is evidence that shortening recoveries is ultimately better for promoting resistance to fatigue. Anecdotally, recovery manipulation is a relatively popular strategy among elite Kenyan runners. When Yobes Ondieki, for example, was preparing to break the world record in the 10K, he completed interval workouts with the work intervals set at exact world-record pace. Over time, he shortened the recoveries between work intervals until recovery time deteriorated to a meager 10 seconds! At that point, Ondieki was running almost world-record 10Ks during his training sessions, and upon breaking the world record, he reported that the record-setting race was actually easier than his preparatory workouts.4

  Runners who sprint 200 meters (.12 mi) can also improve resistance to fatigue and overall performance by using relatively short recoveries. In research carried out at Aristotle University in Greece, speed sessions were conducted three times a week for 6 weeks. Sprinters who used 10-second recovery intervals during workouts that featured 10-second work intervals at maximal speed were quicker during the second 100 meters of all-out 200-meter efforts than those who employed 60-second recovery intervals. In other words, a 1:1 work-to-recovery ratio produced better performances at 200 meters than a 1:6 work-to-recovery ratio. Concentrations of key anaerobic enzymes—glucose-6-phosphate and fructose-6-phosphate—were also significantly higher in the short-recovery sprinters.5

  Enhancing Muscle’s Oxidative Capacity and Lactate-Threshold Velocity

  Elite East African runners have the same O2max values as elite Caucasian runners but have considerably greater resistance to fatigue; the best runners from East Africa can run 21 percent longer at a high-quality velocity (92 percent of maximal speed) compared with topmost Caucasian runners.6 These same East African runners have greater oxidative enzyme activity in their muscles despite not having higher O2max levels, particularly with regard to a key oxidative compound—citrate synthase—that is 50 percent higher in East African runners than in elite Caucasian runners.6 The East Africans also accumulate less blood lactate during strenuous running, indicating that lactate-threshold velocity is higher.6 Thus, it is logical to argue that high skeletal-muscle oxidative capacity and lactate-threshold speed, in concert with heavy neural drive, are factors that promote resistance to fatigue.

  Two different types of workouts enhance skeletal-muscle oxidative capacity and lactate-threshold speed. One type includes sessions that incorporate significant segments at 100 percent of O2max and above, including the following:

  vO2max workouts

  Interval workouts at best 1,500-, 1,000-, and 800-meter race paces

  Maximal-speed sessions with relatively short recoveries

  Demanding circuit-training workouts with tough running components

  Hill repeats and fartlek efforts

  A second type includes sessions that incorporate a warm-up and then about 45 minutes of intense and primarily sustained running that significantly depletes glycogen. The latter is significant because depleted intramuscular glycogen stores create a strong stimulus for aerobic enzyme synthesis within the muscles. An example of such a session for an elite Kenyan might be 7K (4.35 mi) of steady, hard running followed by a short break lasting 5 or 6 minutes and then 6K (3.73 mi) of intense effort.

  Additional Strategies

  Other workout strategies for promoting greater resistance to fatigue include consuming a carbohydrate-rich meal a few hours before the session begins to avoid hypoglycemia and eschewing the common tendency to blast through the first repetition of an interval workout at a speed far greater than the runner’s goal. The faster the first interval, the more likely fatigue is to appear in later intervals within a workout.3 Maintaining motivation is a key factor, too, especially since research reveals that fatigue during workouts can result from reduced neural output.3

  When fatigue is experienced during running, there is often a simultaneous loss of running economy (i.e., an increase in oxygen-consumption rate). Recent research has revealed that runners with excellent muscular-strength endurance, or the ability to maintain muscular-force production by the quads and hamstrings over extended periods during nonrunning tests of strength, suffer smaller decrements in economy during continuous high-intensity running. Thus, it appears that an improvement in muscular-strength endurance preserves running economy during tough
efforts and should thereby augment resistance to fatigue.7 Running-specific strength training is highly recommended for enhancing muscular-strength endurance (chapter 14).

  Various nutritional supplements have been marketed as being energizing fatigue fighters. One of the most interesting of such products is a compound rather mysteriously called (-)-epicatechin. In a recent study carried out at the University of California San Diego, (-)-epicatechin supplementation (1 milligram per kilogram [2.21 lb] of body weight twice daily) boosted running performance by 50 percent and enhanced resistance to fatigue by 30 percent.8 Impressively, oral (-)-epicatechin supplementation had powerful effects on mitochondrial development, muscle capillarity, and muscular oxidative capacity. (-)-Epicatechin is a flavonol naturally found in cacao and tea, but before readers rush to a supplement shop to purchase the product or begin consuming copious amounts of cocoa and green tea, they should be aware that no study has ever linked (-)-epicatechin intake with higher performance in human runners. The San Diego study was carried out with novice athletes—specifically, previously untrained mice. The same is true for most other commercial products marketed as energy promoters. (See chapter 46 for the few exceptions to this rule.)