Running Science

by Owen Anderson

  In a separate study, experienced cyclists completed a 60-minute time trial that included six maximal sprints.9 As predicted by the anticipatory regulation hypothesis, there was a reduction in power output and IEMG activity from the second through the fifth sprint as the nervous system cautiously tempered intensity in order to avoid physiological failure. However, both power and IEMG magically revived—and increased significantly—during the sixth sprint, which took place during the last minute of the overall ride. There was no real magic in the revival, however. Rather, the nervous system simply took the brakes off and allowed nonfatigued muscles to operate at high levels. The muscles were not fatigued during the second through fifth intervals—they were simply reined in by the nervous system.

  Nervous system control of training intensity is a familiar phenomenon to many runners even though the dominant role is often not clearly grasped. Faced with an interval workout consisting of 6 × 800 meters, runners find the first interval to be fast and the second through fifth intervals to be progressively slower. The sixth interval, however, is often the quickest of the entire workout even though peripheral (i.e., muscular) fatigue should be the greatest and body temperature the highest. As the last work interval is reached, the brain is anticipating the ending of the workout and recognizing that physiological limits will not be exceeded even if a high running intensity is maintained. Thus the running pace over that last interval is fastest even though peripheral fatigue should be at its highest point.

  The anticipatory regulation model of fatigue may help explain the dominance of Kenyan endurance runners. Various studies have shown that elite Kenyan athletes can sustain a higher percentage of O2max in their races than runners from the rest of the world.10 While most highly competitive runners toil away at about 90 to 92 percent of O2max during their 10K races, elite Kenyans have the ability to complete the distance at an intensity of 94 to 95 percent of O2max. Traditionally, this difference has been explained as being due to greater resistance to fatigue, but the actual, physiological nature of this heightened resistance has never been detected or adequately explained.

  Swiss researcher Bengt Kayser suggests that in elite competition, the difference between the winner and loser may not be the result of differences in O2max but “rather in how big a safety margin the CNS (central nervous system) imposes in order for the organism to stay clear of serious damage (to the heart and muscles).” Kayser postulates that one reason Kenyans do so well is that “they are able to push the limits imposed by the CNS closer to the danger zone . . .”11 To put it another way, the Kenyans’ governor of exercise intensity is more permissive.

  Training the Brain for Racing

  If the central nervous system regulates performance, it begs this question: “Can you train your brain to allow you to go faster?” To answer this question, first note that anticipatory regulation is of more than esoteric interest to the serious endurance runner: It should also shape racing strategies and training-program creation. It is clear that fatigue and thus distance-running performance are influenced not just by factors related to oxygen consumption, body temperature increases, and muscle metabolite accumulation but also by muscle recruitment by the nervous system and the consequent production of propulsive force—and in which the nervous system anticipates unwanted disturbances in overall physiological equilibrium.

  It is also certain that when runners move up to higher speeds, their nervous systems are recruiting more motor units in their leg muscles and recruiting those motor units more quickly. When runners slow down, they are using fewer motor units and recruiting those units less quickly. Electromyographic studies reveal that EMG values go up during 5Ks as runners speed up and drop as runners decelerate. Since EMG recordings reflect neural input to the muscles, it is clear that pace changes during the race are not the result of fatigue within the muscles but rather are the outcome of changes in stimulation of the muscles by the nervous system. Thus, training that teaches the nervous system to sustain higher outputs, and thus greater inputs to the muscles, should help improve race performances. It is doubtful that this teaching can be best accomplished by long, slow distance training, which features and rehearses low neural inputs.

  Runners who can keep their muscle recruitment by the nervous system at the highest-possible levels fare the best in endurance competition.12 Based on past experience of running, a runner develops the capacity to set the optimal velocity for a competitive effort.13, 14 This again points to the importance of high-quality training, as well as to specific training. That is, those runners who have religiously practiced goal race paces over suitable interval distances during training will have nervous systems that are most ready and willing to lock in those paces during actual race situations.

  High-quality and high-intensity training not only prepare the muscles but also the nervous system to sustain a faster pace over time.

  High-speed training improves motor-unit recruitment and also advances the synchronization of motor units;15 it is best for promoting neuromuscular attributes and for enhancing nervous system tolerance of high-quality running. High-intensity strength training with challenging resistance also enhances neural output to the muscles during activity. Contrary to popular belief, high-quality training is also optimal for advancing aerobic attributes since high training speeds are generally closer to O2max than long-run pacings. The constant proximity to O2max forces the heart to become a better oxygen pump and the leg muscles to become better oxygen users, raising aerobic capacity and even vO2max since fast-pace training also enhances economy.

  Conclusion

  These findings should lead to changes in the overall planning of workouts. The time-honored routine of the weekly Sunday long run should be replaced with a long run every third Sunday and explosive routines on the other two Sundays. These Sunday explosive days, featuring plyometric drills, high-speed and running-specific strength training, and high-velocity running intervals, would force the runner’s anticipatory regulation system to reset and would create a nervous system that would be much more permissive to high running intensities, allowing greater speeds to be maintained for longer periods. Such training recognizes the dominating impact of the brain in anticipating the velocity that is manageable for each quality workout and race and then regulating that speed throughout the overall exertion.

  Chapter 49

  Psychological Strategies for Improved Performance

  A runner’s psychological state has a profound effect on his or her physiological response to running. This basic truth has been known for more than 30 years. Initial research carried out by exercise scientists in the 1970s and 1980s revealed that individuals using meditation and relaxation techniques were able to walk significantly longer on a treadmill at an intensity of 80 percent of O2max compared with exercisers who did not use such techniques.1 Several other studies demonstrated that the use of simple stress management strategies significantly decreased oxygen consumption rates during exercise.

  The major role played by the mind in determining the physiological reaction to exercise was illustrated by a study in which individuals who were actually lifting 10- to 16-kilogram (22-35 lb) weights were told that they were either lifting 0.3- or 30-kilogram (0.66 or 66 lb) weights. When they were informed of the purported light loads, the lifters’ ventilation and oxygen consumption rates plunged by 20 to 30 percent; the deception that 30-kilogram weights were being used caused increases of about 50 percent in ventilation rate and oxygen usage.1

  The conclusions reached from such research were that emotions and thoughts can influence a runner’s physiological state rather dramatically during workouts and competitions—and that runners should develop mental strategies that decrease the energy cost of running at specific velocities as well as coping strategies for dealing with the fatigue and discomfort of strenuous effort. A fundamental concept is that a runner in the same physical condition as another athlete will hold a competitive advantage over that individual at any race pace by having more positive perce
ptions of his or her ability to continue and fewer negative and pessimistic thoughts concerning the feelings of pain and fatigue coming from the legs and other parts of the body.

  Mental Coping Strategies

  Early research suggested that there are three basic kinds of mental coping strategies that runners can use in an attempt to enhance performance:2

  Association occurs when runners constantly monitor body sensations (e.g., respiration rate, respiratory comfort, body temperature, muscle pain, muscle tightness), remind themselves to relax, and modify stride and pace in order to produce greater comfort and economy.

  Dissociation is when runners block out bodily feelings instead of focusing on them and ignore pain, fatigue, or boredom by concentrating on a favorite or pleasant subject or repeating a mantra.

  Positive self-talk involves repeating phrases such as “I can do it,” “I’m not really tired,” or “I’m going to make it” at key points during a hard workout or competition.

  A classic study suggested that elite runners tend to use association during intense running while less-experienced runners prefer to engage in dissociation.3 Research concerning the effectiveness of these strategies has produced conflicting results. In one study, treadmill runners listening to a tape recording of street sounds (an example of dissociation) experienced reduced fatigue and a lower frequency of sore muscles compared with runners who were running at the same pace but concentrating on the sounds and feelings associated with their breathing (an example of association).4 Dissociation has also proved to be better at delaying feelings of strong discomfort during exercise.4 However, such investigations have seldom looked at the effects of coping strategy on actual performance.

  In an investigation in which running performance was monitored, 60 runners who ordinarily ran about 15 miles (24 km) per week were divided into four equal groups and asked to run as far as possible on a track in 30 minutes.2 One group attempted to ignore feelings of exertion and imagined themselves engaged in a pleasant activity unrelated to running during the 30-minute effort (dissociation). A second group constantly monitored body sensations while running and paid close attention to feelings related to breathing, fatigue, and the conditions of the stomach and leg muscles, altering running velocity according to how they were feeling (association). Members of the third group gave themselves pep talks during the 30-minute exertion (positive self-talk) while the runners in the fourth group received no instruction about mental strategy.

  The four groups performed equally well on the track, covering about the same distance with similar heart rates and feelings of fatigue, challenging the principle that coping strategy plays a large role in performance. However, for a psychological strategy to alter performance, a runner would probably have to not only use the strategy but also believe that it would be effective. Such belief would probably only be acquired after adequate training while using the strategy—and as a result of successful racing with the strategy in play. In the 30-minute, four-group study, instruction in the use of the various strategies was quite brief in nature.

  Attention Control

  Association and dissociation are examples of attention control, a topic of great interest to sport psychologists. Despite the rather unconvincing research concerning the effectiveness of association and dissociation, the optimization of attention control may produce significant gains in running performance.5 Feelings of fatigue, day-to-day concerns, anxieties about family and business affairs, and thoughts of past poor performances or unsatisfactory training sessions tend to intrude into runners’ thoughts, making it hard to relax and focus on the coordination of running gait. It is possible that negative thinking might also decrease neural output to the muscles during strenuous efforts, thus diminishing running pace. In theory, once distracting thoughts are minimized through the development of proper attention control, a runner’s nervous system can focus completely and freely on the act of running at a best-possible pace.

  Famed men’s basketball coach John Wooden of UCLA was a noted proponent of proper attention control development. The Westwood legend permitted large numbers of boisterous spectators to attend UCLA practices and instructed the UCLA pep band to play the upcoming-opponent’s fight song during important practices before road games even though the raucous sounds drowned out coaching instructions and communications between teammates. Wooden believed that regular exposures to distracting circumstances enhanced the ability of his athletes to concentrate during games, and his Bruin players were noted for their unflappability and mistake-free play.

  The use of attention control appears to be beneficial to endurance runners. In one attention-control study, 18 collegiate distance runners were divided into three equal groups.6 Over a 6-week period, six of the runners were given psychological skills training (PST), which included guidance in the use of attention control, relaxation techniques, and self-instructional tutoring. Six other runners were told about the potential value of psychological skills training and were given a description of what it entailed—but did not practice attention control or any of the PST techniques. Six other runners served as controls: They received no instruction or practice in PST and were not informed of its possible value.

  Running training was identical in the three groups; not surprisingly, O2max and percent body fat did not change in any of the groups during the 6-week study. At the beginning and end of the study, all 18 runners participated in a continuous exercise test that contained the following elements:

  Six minutes of treadmill running at a moderate intensity of 50 percent of O2max

  Six minutes of treadmill running at an intensity of 60 percent of O2max

  Six minutes at an intensity of 70 percent of O2max

  Four minutes at 80 percent of 2max

  Four minutes at 90 percent of O2max

  One minute at the lofty intensity of 98 percent of O2max

  After the challenging minute at 98 percent of O2max, the 27th minute of continuous running, the treadmill grade was changed from level to 2 percent, and the athletes ran for as long as they could, simulating a final drive to the finish line in the closing minutes of a 10K race. Once the treadmill incline was lifted to 2 percent, the runners were actually exercising at an intensity of 100 percent of O2max.

  At the beginning of the research, all 18 athletes were able to run for about 60 seconds after the treadmill grade was raised. After the 6 weeks of psychological skills and attention-control training, PST participants were able to run for 115 seconds during this rugged final stage of the test, a 55-second improvement. The other 12 runners were not able to improve their performances.

  Running economy also improved significantly for the six runners who had taken part in PST, with oxygen demand dropping by 4 percent at moderate intensities of 50 to 70 percent of O2max. This allowed runners engaged in PST to run about 15 seconds per mile faster after the 6 weeks of training—without any significant increase in effort. At higher intensities (80 to 98 percent of O2max), there was a tendency for the PST runners to be more economical. None of the non-PST athletes managed to improve running economy.

  Body Checking

  The attention-control skills developed by the PST runners included body checking, a practice in which a runner systematically checks in with his or her head, neck, shoulders, chest, stomach, back, hips, thighs, knees, lower legs, ankles, and feet to see if they are complaining about tension, fatigue, or pain. Each body region is relaxed as it is checked. During body checking, family disputes, checkbook balances, a troublesome week at work, and all other intruding thoughts are not permitted: A runner’s entire focus is on checking, relaxing, and regulating the body.

  According to principal researcher Jeffery P. Simons, body checking prevents runners from dwelling on their worst nemesis: fatigue.7 During a body check, the part of the body that is feeling the most fatigued is quickly identified and remedial action is immediately taken. If the legs feel uncomfortable, unresponsive, and fatigued, for example, a runner can concentrate totally on relax
ing the lower limbs and on changing or quickening strides slightly. This seems to immediately relieve discomfort and would cause the leg muscles to be used in slightly different ways, potentially recruiting less-fatigued motor units. The focus on the legs might also increase neural output to the leg muscles.

  Many of the PST trainees who performed well during the maximal exercise test reported that they ran at such a high level because they “had something to think about” as they attempted to deal with the rugged intensity and its associated discomfort. They were thinking about their bodies and about ways to relax and change their strides, at the same time refusing to get carried away by performance-crippling sensations of pain and fatigue.

  Attention control, used in this manner, is a clear example of association rather than dissociation. “The trouble with dissociation,” says Simons, “is that it causes a loss of concentration and a decrease in self-monitoring, leading to a diminishment of self-control and thus poorer running performances. If you want to run well, it’s much better to stay on top of what’s happening in your body. Eventually, PST runners get so good at self-awareness that a coach can yell ‘body check’ and see an immediate response from the standpoints of more-relaxed, more-economical running.”