Running Science

by Owen Anderson

  One caveat is in order: Although blood-lactate tests do not appear to be sensitive indicators of changes in fitness, the study did find an apparent link between running velocity at lactate threshold reproducibility and high fitness levels. Thus, truly elite athletes may have fairly low natural variations in running velocity at lactate threshold; consequently, their blood lactate tests might have greater power. Further research will have to establish this, however; we cannot assume that this is the case based on one study.

  Reproducibility of Rating of Perceived Effort

  As mentioned, in the Glasgow-Galway study, heart rate at running velocity at lactate threshold was also not highly reproducible. Unfortunately, the story for rating of perceived effort (RPE) was not much better. In the Glasgow research, RPE at running velocity at lactate threshold was found to average 14.1, while RPE at a blood lactate level of 4 mmol/Liter (72 mg/dl), a blood lactate concentration often recommended for training sessions focused on improving lactate threshold, settled at 17.2 out of a maximal score of 20. However, there was again rather wide variability, suggesting that the use of RPE to prescribe workout intensity would be unwise. Overall, an athlete would have to lower RPE at a specific running velocity at lactate threshold by about 3 Borg-scale units (!) in order to assume that a real change in running velocity at lactate threshold had taken place. As the researchers pointed out, “This wide range highlights that the use of RPE to prescribe intensity at [lactate-threshold velocity] has severe limitations.”

  The RPE story is interesting in its own right. Like lactate, RPE varies according to emotional state and diet. High-carbohydrate diets tend to produce lower RPE scores, for example, while high-fat diets shoot RPE upward. Interestingly, the sex of the athlete appears to have no significant, repeatable effect on RPE, but RPE is influenced by the interaction between the sex of the athlete and that of the experimenter. Men and women revise RPE based on the gender of the person they are reporting to. So, in most cases, female scientists or lab assistants take RPEs from female athletes while males jot down the RPEs of male athletes.

  In addition, RPE seems to depend to some extent on personality type. Extroverts, for example, generally have lower RPEs during strenuous exercise compared with introverts. The theory underlying this phenomenon is that introverts are bothered to a greater extent by sensory information flowing into their central nervous systems, including the sensations associated with strenuous exercise.

  Conclusion

  Because running velocity at lactate threshold advancement is a key element of middle-distance and endurance running, a process to maximize improvements should continue throughout the training year. The good news for coaches and runners is that complicated training techniques and sophisticated mesocycles, or periods, of training are not necessary to optimize this variable. Rather, steady use of high-quality workouts throughout the year will keep running velocity at lactate threshold advancing. That being said, an important key is to employ a variety of high-quality workouts, alternating sprint, vO2max, superset, lactate-stacker, circuit, and 5K-paced sessions throughout the year; make these workouts more difficult with faster speeds and more reps, for example, as fitness improves.

  Chapter 28

  Increasing Maximal Running Speed

  For endurance runners, there is considerable uncertainty about how to improve maximal running speed, which is the top velocity that a runner can achieve during an all-out sprint lasting from 20 to 300 meters from a running start. This lack of certainty is partly the result of the traditions of long-distance running that emphasize prolonged submaximal runs as a key element of training while ignoring, or at least deemphasizing, high-speed efforts (chapter 11); these latter efforts are often thought to be anaerobic in nature and thus antithetical to the development of aerobic capacity and the enhancement of endurance. As a result of these traditions, many distance runners and coaches do not take a systematic approach to the development of a higher maximal velocity.

  Research reveals that this is a mistake. As described in chapter 11, researcher Kris Berg and his colleagues at the University of Nebraska at Omaha demonstrated that 300-meter sprint time; near-maximal velocity; and plyometric leap distance, also associated with maximal muscular power, were able to explain most of the variation in 10K running performances.1 Additionally, in an investigation carried out with 17 experienced endurance runners with 5K performance times ranging from about 17:00 to 18:50, Heikki Rusko, Leena Paavolainen, and Ari Nummela of the KIHU Research Institute for Olympic Sports in Finland discovered that 20-meter race speed (i.e., maximal velocity) was an excellent predictor of 5K finishing time, far better than that vaunted variable O2max.2 This was true even though 20-meter velocity—8.15 meters per second—was 76 percent faster than the runners’ mean 5K speed of 4.63 meters per second. If 8.15 meters per second seems unusually fast for an endurance runner, bear in mind that the runners in this study were given a flying 30-meter head start before embarking on the 20-meter efforts.

  Training for Maximal Speed

  While some long-distance runners do recognize the importance of developing a higher maximal running speed, the training approach taken to improve maximal speed often revolves around carrying out intervals on the track at 5K pace or a similar intensity. While this kind of preparation can certainly upgrade O2max, enhance running economy, and velocity at lactate threshold, there is no evidence to support the idea that such running improves maximal speed.

  There is an important distinction to be made between speed and maximal speed. As a result of an improvement in overall fitness, a runner might be able to complete a 10K race at a brisk tempo that was previously associated with his or her 5K or 8K (3.1 or 5 mi) competitions. This would of course lead to a 10K personal record, and the runner might pronounce that he or she is faster or has developed more speed. While it is true that this runner is moving at a faster average speed during the 10K, what the runner has actually done is to take a familiar pace and extend the distance over which he or she could sustain that tempo. He or she can run at a higher average speed over an extended distance but has not necessarily pushed the envelope and advanced maximal speed.

  The training path that needs to be taken to increase maximal speed is most likely different from the various strategies that can be used to extend a specific race pace to a longer competitive distance. Because maximal speed is such a strong predictor of finishing time among endurance runners, upgrading maximal speed should lead to additional improvements in distance performances beyond the gains associated with training at below the maximal speed. Training carried out by endurance runners should optimize maximal running speed.

  Training Modes Examined by Research

  Research investigating the ways in which endurance runners can increase maximal speed has not been very systematic, in part because it is nontraditional to think that upgrades in maximal speed promote improved running in long-distance events completed at submaximal intensities. Research has focused on four possible training modes that have been logically linked with the upgrading of maximal speed; the results have shown that some of these methods far exceed the others.

  High-speed uphill and downhill running

  Running against resistance (e.g., pulling a weighted sled)

  Strength training in conjunction with quality running

  Explosive training

  High-Speed Uphill and Downhill Running

  Scientific investigations suggest that fast running on slightly inclined uphill and downhill surfaces is a more effective way to improve maximal speed than fast training on a horizontal surface. In a study carried out in the department of physical education and sport science at the University of Athens in Greece, runners who carried out 8 weeks of training that involved running as fast as possible on slight uphill and downhill inclines improved their maximal running speed during 35-meter sprinting by 4.3 percent; those who ran similar distances explosively on a flat surface upgraded maximal speed by just 1.7 percent, and a control group failed to improve maxim
al speed at all.3 A key mechanism underlying the augmentation of maximal speed appeared to be a reduction in contact time (i.e., the amount of time spent on the ground by each foot per step) during fast running: Contact time fell by 5.1 percent after the uphill and downhill sprint training. A decrease in contact time increases stride rate during fast running and—provided there is no resulting decrement in stride length—thus improves maximal speed.

  Research has made a limited attempt to uncover the optimal slope for uphill and downhill training designed to increase maximal speed. A slope of 3 degrees has been proposed by various investigators as the best possible incline for such workouts. In a study carried out at Marquette University, 13 NCAA Division III athletes ran 40-yard (37 m) sprints on downhill slopes of 2.1, 3.3, 4.7, 5.8, and 6.9 degrees in random order.4 The 5.8-degree slope was best for developing the highest acute speed during the training sprints; it shortened 40-yard (37 m) sprint time by .35 seconds, a 6.5 percent decrease compared with results from flat-ground running. The slope that produced the next fastest times was the 4.7-degree decline, but times on that slope were about 2 percent slower than on the 5.8-degree slope. A presumption is that the advantage of slope running is that it permits higher training speeds compared with flat running and thus fosters special adaptations that enhance maximal running speed. If this assumption is accepted—and it is certainly reasonable to do so—then a logical choice for training would be the decline that allows the fastest possible running.

  During downhill running, the foot falls farther with each step compared with running on flat ground. Thus, the collision of the foot with the ground occurs at a higher speed during downhill running because of greater downward acceleration of the foot. This should force a runner’s nervous system to adapt in ways that enhance coordination of foot strike at high speeds. This is possibly the direct mechanism that produces the decreased contact times and thus higher stride rates observed after downhill training and could certainly produce a higher maximal speed. Since maximal running speed equals stride rate times stride length, any adaptation that produces a greater stride rate without harming stride length will increase maximal running speed.

  Running Against Resistance

  Some coaches and exercise scientists have theorized that running as hard as possible against resistance might increase maximal running speed. Theoretically, such training should increase leg strength in a running-specific way and thus lead to natural expansions in stride length, which could heighten maximal running speed as long as there were no counterbalancing decreases in stride rate.

  However, research suggests that running against resistance is actually less effective from the standpoint of improving maximal speed. In a study carried out in the department of physical education and sport science at Aristotelio University in Thessaloniki, Greece, one group of athletes followed a sprint-training program that involved pulling a 5-kilogram (11 lb) sled during sprint routines while a second group carried out all training without added resistance.5 For both groups, the training protocol involved 4 × 20-meter and 4 × 50-meter maximal speed runs three times a week for 8 weeks.

  Although the sled training improved acceleration during the first few meters of all-out 50-meter sprinting, it failed to upgrade stride rate, stride length, or maximal speed between meters 20 and 50. In contrast, training without resistance improved maximal running speed between meters 20 and 50 by the end of the study.

  The apparent problem with using resistance is that it slows average training speeds, an effect that would fail to optimize the nervous system’s control of high-speed running. It is possible that training using resistance also changes running mechanics in an unspecified way and thus does not spike running speed. Research carried out by Rusko and C. Bosco has shown that running while wearing a weighted vest to provide additional resistance actually has a negative effect on running economy after the vests are taken off, suggesting that the use of increased resistance can alter running form in a negative manner.6

  Strength Training in Conjunction With Quality Running

  Research reveals that combining strength training with high-speed running workouts can upgrade maximal running speed. In a study carried out at the department of health and exercise science at the College of New Jersey, 25 male athletes were matched for 30-meter sprint times and assigned for 7 weeks of training to one of three groups: (1) sprint training only, (2) strength training only, or (3) combined sprint and strength training. The sprint training was conducted twice a week and consisted of 8 to 12 sets of maximal 40- to 60-meter sprints with rest intervals of 2 to 3 minutes. The periodized strength training, relying on squats and other related activities, was performed four times per week, with 3 to 4 sets of 6 to 10 repetitions of each exercise per workout. Combined sprint and strength work used both protocols for the 7-week period. All three groups upgraded 1RM (one-repetition maximum) squat strength, but 30-meter sprint times improved significantly only in the group that had combined sprint and strength training.7

  Explosive Training

  Research strongly supports the notion that maximal running speed can be enhanced by explosive training (i.e., work that focuses on fast sprints and extremely quick drills, especially exertions that bear a biomechanical resemblance to some aspect of the gait cycle of running). In an investigation carried out at the University Pablo de Olavide in Seville, Spain, students who performed just one explosive activity—drop jumping—twice a week were able to increase 20-meter sprint time significantly by about 3 percent compared with controls. Drop jumping involves falling from a box and then leaping forward at the instant of contact with the ground. The drop jumps were completed from three different heights (20, 40, and 60 cm [6, 16, and 24 in]), and about 60 drop jumps were performed per workout.8

  The classic study carried out by Paavolainen, Rusko, and colleagues at the KIHU Research Institute for Olympic Sports in Finland provided the strongest support for the use of explosive drills to improve maximal running speed in endurance runners.1 Over a 9-week period, a group of experienced 5K runners replaced about 32 percent of their traditional endurance training with explosive work involving high-speed sprints, bounding drills, bilateral countermovement jumps, drop and hurdle jumps, hops, and squats; the drop and hurdle jumps involved dropping from a box or platform to the ground and then leaping, or rebounding, over a hurdle. Despite the loss of 32 percent of their endurance training, which involved running long distances at submaximal paces, these runners improved 20-meter sprint time by nearly 4 percent and 5K performance by almost 3 percent without any uptick in O2max.

  Paavolainen and Rusko attributed the improvements in these performances to “improved neuromuscular characteristics” in the runners who received explosive training. They meant that these runners could produce greater amounts of propulsive force in shorter periods of time during the stance phase of running compared with control runners. Thus, in this study, stride rate increased without any decrement in stride length, elevating maximal velocity.

  In a follow-up study also completed by Rusko and colleagues at the KIHU Research Institute for Olympic Sports, 13 young distance runners replaced 19 percent of their traditional endurance training with explosive work involving jumps, hops, and sprints. This simple change enhanced 30-meter sprint time by 1.1 percent; the control group failed to improve at all.9 Tests revealed that the runners using explosive training had improved the force-time characteristics of their muscle actions (i.e., their muscles were producing more force in a shorter time), and that there was more rapid neural activation of their muscles following the explosive training. As Rusko pointed out, most of the improvement in sprint time could be explained by changes in nervous system activity.

  While most explosive training takes place without added resistance, there has been considerable speculation about the optimal resistance to use for explosive training. One school of thought suggests that relatively heavy loads (about 80 percent of 1RM, for example) are superior because they automatically induce a rapid, dramatic increase
in neural output in order to handle the greater resistance. A contrasting view is that lighter resistances are preferable since they permit quicker movement speeds. Specifically, it has been suggested that loads that maximize power output (i.e., permit the attainment of Pmax, the highest possible level of power) would be best.

  Surprising to some runners, such loads are not high percentages of 1RM since heavy resistance slows down movements and thus harms power, which is expressed as force produced per unit of time. It is commonly stated that Pmax for a specific movement occurs at about 30 percent of 1RM, but this may actually be far below or well above Pmax in individual runners. Since there is considerable variation among runners, this variation in Pmax probably depends on the movement under consideration.

  In a study that examined the effects of strength training with a heavy load versus strength training at Pmax on maximal running speed, 18 well-trained rugby players were randomly divided into two groups; each group had an equal volume of training for a 7-week period.10 One of the groups performed squat-jump training with heavy loads at about 80 percent of 1RM; the other carried out squat-jump work at Pmax at 20 to 43.5 percent of 1RM depending on the athlete. Sprint times for 10 and 30 meters improved by about the same amount for both groups after 7 weeks, leaving this question open for further research. It is possible that a combination of heavy load and Pmax training would be optimal for enhancing maximal speed since heavy-load training might optimize propulsive force during the stance phase of gait and Pmax training might optimize the rate of propulsive-force application during stance. The former would advance stride length, and the latter would increase stride rate.