Position eight hurdles in a row, 45 inches (1.1 m) apart, with the height of each hurdle set at 23 inches (58 cm). Starting from one end, jump over each hurdle (figure 23.25), landing and taking off on two legs until all eight hurdles have been cleared. Maintain continuous movement. Minimize ground-contact time with each landing and try to be as explosive as possible. Once you have cleared the eighth hurdle, jog back to the beginning point and repeat 4 more times for 5 reps in all. Avoid taking little hops between hurdles and making more than one contact between hurdles. This exercise ,may also be performed on one leg at a time as a progression.
Figure 23.25 Single contact with explosive take off.
One-Leg Hop in Place
Purpose
The purpose of this exercise is to promote explosiveness in a running-specific manner.
Execution
Stand with one foot forward and one foot back with feet about one shin-length apart front to back and hip-width apart from side to side. Place the toes of back foot on a block or step 6 to 8 inches (15 to 20 cm) high. Direct your weight through the middle to the ball of the supporting foot. Hop rapidly on the supporting foot at a cadence of 2.5 to 3 hops per second, or 25 to 30 foot contacts per 10 seconds for the prescribed time (figure 23.26). Lift the knee of the hopping leg about 4 to 6 inches (10 to 15 cm) with each upward hop; keep the other leg and foot stationary on the block. Keep the hopping foot striking the ground and springing upward rapidly as if in contact with a hot stove. Keep the hips fairly level and virtually motionless throughout the exercise with little vertical displacement. After completing the first set, rest for a moment, and then repeat the one-leg hops on the other leg. Rest again and perform one more set on each leg. A set is 60 seconds of continuous hopping on one foot.
Figure 23.26 One-leg hop.
Diagonal Hop
Purpose
The purpose of this exercise is to improve explosiveness, coordination, and ankle strength.
Execution
Jog a few strides and then move diagonally to one side (figure 23.27a). When the foot that moved to the side makes contact with the ground, hop once quickly in place. Then, explosively jump diagonally forward, landing on the other foot (figure 23.27b). When this foot makes contact with the ground, hop once quickly in place and then explode diagonally in the opposite direction. Repeat the cycle for about 40 meters. Stay relaxed at all times and move in a rhythmic, coordinated manner. Look straight ahead, not at your feet.
Figure 23.27 Diagonal hop (a) take-off and (b) landing on opposite foot.
Greyhound Run
Purpose
The purpose of this exercise is to improve maximal running velocity.
Execution
Use an area with 100 meters of unobstructed surface. Accelerate for 20 meters (66 ft), maintain a nearly maximal pace for 60 meters (196 ft), decelerate for 20 meters, rest for several seconds while walking, and repeat in the opposite direction. Complete 8 of these 100-meter greyhound runs, 4 in each direction.
Conclusion
Although strength training is excluded from many runners’ training programs or treated as occasional cross-training to be carried out on nonrunning days, it is the backbone of great endurance running training. When overall training is periodized to include phases of general strengthening, running-specific strengthening, hill training, and explosive work, running fitness can be maximized; each form of strengthening builds on the previously completed modalities. Within each phase, proper progressions are included to gradually expand resistance and overall exertion difficulty. High-quality running training wraps around the strength-training backbone and ensures that the seven key performance variables will be optimized: vO2max, tlimvO2max, running economy, lactate-threshold velocity, resistance to fatigue, running-specific strength, and maximal running velocity.
Part VI
Optimal Training for Specific Conditioning
Chapter 24
Increasing O2max
Most runners and running coaches believe that it is essential to build a base of strength, aerobic capacity, and fitness prior to embarking on a rigorous training program. A popular conception is that this base should include gradually increasing distance, most of which is conducted at easy to moderate tempos. It is generally believed that a runner’s body is not yet ready for high-quality work during an early, base portion of the training year and thus must be gradually acclimated to higher volume and intensity. The easy running is thought to provide a foundation of strength and serve as an upgrade of aerobic fitness that helps smooth the transition into higher-quality effort.1 However, evidence shows that this traditional approach and its alleged benefits may not be optimal for improving O2max and running specific strength.
Weaknesses of Traditional Approaches to Base Training
In their book Better Training for Distance Runners, David Martin and Peter Coe suggest that base periods should contain “sizable volumes of continuous, longer-distance running at below race pace for any of the middle- and long-distance running events.”2 Martin and Coe indicate that base running should be “conversational” in nature—slow enough to permit easy talking during a workout. They recommend a base training intensity of between 55 and 75 percent of O2max, which would be well below marathon pace for most runners, and they even provide a method for runners to use to determine whether their training speeds fall within this range of intensities. Martin and Coe caution against running faster than 75 percent of O2max during a base period because such effort “causes the beginning of anaerobic glycolytic activity, which may mark the beginning of lactic-acid accumulation that is not appropriate for training emphasis in this zone.”2 No evidence is provided to demonstrate that lactic-acid accumulation is counterproductive during base periods, however.
In his book Daniels’ Running Formula, coach and exercise physiologist Jack Daniels indicates that base training, which he calls “phase-one” work, should consist of easy running plus a few strides (i.e., brief intervals of accelerated running) regardless of whether one is a middle- or long-distance runner.3 For Daniels, an optimal duration for a base period is about 6 weeks, and the easy running performed during such a period is believed to foster “cell adaptation and injury prevention.”3 Unfortunately, Daniels cites no research that documents optimal cellular adaptation and enhanced injury prevention with this approach compared with other forms of base training that include higher-quality running or strength training.
Coach Arthur Lydiard was also a proponent of base periods that keep intensity at a moderate level while gradually increasing mileage.4 Lydiard’s theory was that such running improves runners’ aerobic capacities dramatically by enhancing cardiac output, increasing aerobic enzyme concentrations inside muscle cells, and expanding the number of capillaries around individual muscle cells. Capillaries are the tiniest blood vessels in a runner’s body; they are the components of the cardiovascular system that actually deliver oxygen to working muscle fibers. Lydiard eschewed fast running during base periods, believing that such efforts promoted the production of lactic acid—his favorite muscle nemesis—with consequent damage to muscle cells. As discussed in chapter 7, scientific research reveals that lactic acid does not actually harm muscle fibers.
Cell adaptation, prevention of future injuries, increased cardiac output, advanced aerobic enzyme concentrations, and greater capillarization appear to be appropriate—if limited—goals to aim for during base periods. Scientific research indicates that such changes would at least improve O2max and thus place subsequent running training on a higher plain of fitness.
There are two basic problems with these approaches, however. First, running science has not been kind to the traditional idea that easy training intensities are optimal for O2max improvement during base periods. Second, these approaches represent old-school thinking with the focus of training centered almost entirely on cardiovascular and oxygen-usage development and almost no emphasis placed on neuromuscular progress, that is, the ability of the nervous system to recrui
t the leg muscles in ways that enhance coordination and quickness and thus boost maximal running speed. It is difficult to comprehend why this critically important, latter process should be ignored.
Aerobic Development Through Capillary Growth
To fully understand the impact of different types of base training on O2max improvement, it is important to examine research that pertains to aerobic development during base periods. In 1934 exercise scientists were first able to show that endurance training increases capillary densities within animal muscles; the same effect was finally observed in human subjects in the 1970s.5 This important capillary adaptation was apparent when scientists measured either the number of capillaries per muscle fiber or the density of capillaries per square millimeter of muscle tissue, and investigators estimated that the additional capillaries that sprung up around muscle cells as a result of training could spike intramuscular blood flow by 50 to 200 percent.6 While this study was completed with rodents, the changes are likely similar in humans. This would have a profound impact on O2max by increasing the rate of delivery of oxygen to muscles.
Although new capillary growth is often considered to be one of the slower adaptive processes associated with endurance training, an interesting finding was that capillaries began to proliferate around muscles even before the sinews exhibited increased concentrations of intracellular aerobic enzymes in response to training.7 The discovery that new capillary growth is a relatively quick process carried with it the implication that many weeks of steady, moderate running were not required to boost capillary densities.
Advanced capillary density is usually tightly connected with a burgeoning O2max, and a higher aerobic capacity permits training to be conducted for more prolonged periods and at higher intensities. Both of these outcomes are ideal developments for base training periods that are supposed to prepare runners for tougher times ahead. Since these early studies were conducted, exercise scientists have searched for the best ways to promote optimal capillary growth and produce the greatest upswings in O2max.
Impact of Volume, Frequency, and Intensity
Many scientific studies have attempted to sort out the effects of volume, frequency, and intensity of training on O2max. In an important inquiry, Dr. T. Jurimae and his Finnish colleagues asked two groups of university students to engage in 8 weeks of base running training.8 The total volume of training was identical for the two groups, but the intensities were significantly different. One group of runners carried out their base training at an easy intensity of 140 to 150 heart beats per minute while the second group used a higher intensity of 165 to 175 beats per minute. Average maximum heart rate for both groups was about 200, so the easy-running group worked at approximately 70 to 75 percent of maximum heart rate while the harder-running group trained at 82 to 88 percent.
Base periods should improve a runner’s physiological status; they should not simply preserve the status quo. The underlying idea in base training is to move forward and prepare for the more strenuous impending training by upgrading basic fitness. As this Finnish study showed, 8 weeks of training at the lower, traditional base intensity (i.e., 70 to 75 percent of maximum heart rate) failed to improve O2max at all; working more intensely (i.e., at 82 to 88 percent of O2max) enhanced O2max significantly. There was no increased risk of injury at the higher intensity. This study suggested that the lower intensities commonly chosen for base training periods are actually poor choices since they had no positive impact on O2max and presumably capillarization, too. This would be especially true for experienced runners who already have relatively high aerobic capacity.
Advocates of easy running during base periods might argue that the lower-intensity group in this Finnish study could have achieved the same O2max spike as the high-quality runners by boosting their volume (i.e., distance run) during the base period. However, the best predictor of injury in endurance runners is the total time spent training.1 Thus, major increases in distance run during base periods, undertaken in hopes of raising aerobic capacity, might produce a result that is the exact opposite of one of the fundamental goals of base training: Instead of lowering the risk of subsequent injury, such base training might increase the risk of injury.
In a separate study, Glenn Gaesser and Robert Rich of the University of California at Los Angeles asked two groups of healthy young men to initiate base training.9 All the subjects worked out three times a week for 18 weeks, but a high-intensity group trained for 25 minutes per workout at an intensity of 80 to 85 percent of O2max, while a low-intensity group trained for double the amount of time—50 minutes per session—at an easy intensity of 45 percent of O2max.
In this study, the use of light intensity and the doubling of total training time were not advantageous. After 18 weeks and 1,350 total minutes of training, the high-intensity group had improved O2max by almost 20 percent, while the low-intensity group had upgraded O2max by 17 percent with 2,700 minutes of workouts. In other words, the slow-paced, traditional base training tended to produce less improvement in aerobic capacity than the higher-quality base training even when the low-intensity trainees increased total workout time by 100 percent. This study suggested that traditional base-training plans are inefficient ways to bolster running fitness.
Key information about the type of training necessary for O2max expansion during base training periods is also available from studies that have looked at training-related changes in muscle cells’ aerobic enzyme concentrations. An important discovery through this work is the so-called saturation response, which indicates that there is a specific workout duration beyond which little further stimulus for aerobic enzyme improvement can be created. The research has been carried out with rodents, not humans, but it suggests that about 60 minutes of training per workout represents the saturation point beyond which the postworkout adaptive process will produce no further increases in aerobic enzymes.10 Shifting from 60 to 90 minutes per session does not increase aerobic enzyme concentrations by 50 percent, nor does changing from 60 to 120 minutes double enzyme levels. The saturation response strongly implies that such workout expansions will have little effect on aerobic enzyme concentrations.
If a similar effect is present in human runners, the benefits of expanding workout durations beyond 60 minutes during base training periods would be questionable. It is possible that setting the workout duration at about 60 minutes during a base period and then attempting to increase the intensity of effort within that hour might work much more effectively in improving aerobic enzyme concentration, capillary density, and O2max compared with moving to a 75- to 120-minute workout at a lower intensity.
Improving O2max Through Intensity
Research suggests that manipulations of intensity—not volume—represent the most powerful ways to upgrade O2max and capillarization during base periods. In a rigorous investigation,10 Gary Dudley and his colleagues at the State University of New York at Syracuse made laboratory rats use a variety of different workout durations—from 5 to 90 minutes per day—and a range of training intensities from 40 to 100 percent of O2max. Dudley and colleagues examined the effects of duration and intensity on O2max and specifically analyzed how different training modalities influenced fast-, intermediate-, and slow-twitch muscle fibers.
As mentioned, these researchers were able to demonstrate that training for more than 60 minutes per day was without benefit in terms of increasing aerobic enzyme concentrations for all three muscle-cell types. The researchers also concluded that 10 minutes of running per day at an intensity of 100 percent of O2max were enough to roughly triple aerobic enzyme concentrations in fast-twitch muscle fibers over an 8-week period. In contrast, running for 27 minutes at 85 percent of O2max increased aerobic enzymes by only 80 percent, while 60 to 90 minutes of daily running at the traditionally preferred base intensity of 70 to 75 percent of O2max moved enzyme levels up by just 74 percent in fast-twitch cells.
In intermediate muscle cells, which are from a physiological standpoint roughly half-way between fast-twitc
h and slow-twitch fibers, training intensity also had the most powerful effect on aerobic enzyme improvement. Just 10 minutes of running daily at 100 percent of O2max increased aerobic enzyme concentrations just as much as running 27 minutes daily at 85 percent of O2max or 60 to 90 minutes at 70 to 75 percent of O2max. Presumably, using a workout containing 10 minutes of running at 100 percent of O2max broken into intervals plus approximately 20 minutes at 70 percent of O2max would have a far-greater impact on aerobic capacity than the conventional 60 to 90 minutes at 70 to 75 percent of O2max.
For slow-twitch fibers, running a total of 2,400 minutes (40 hours) at an intensity of 70 to 75 percent of O2max increased aerobic enzyme concentrations by approximately 40 percent. That change works out to be an improvement of .017 percent per minute of training. Running for a total of 1,080 minutes (18 hours) at 85 percent of O2max created a 28-percent upturn in aerobic enzyme levels, a change of .026 percent per minute of training. Finally, running fast for 400 minutes (6.67 hours) at close to 100 percent of O2max expanded aerobic enzymes in slow-twitch cells by 10 percent, a .025-percent per minute rate of improvement. When the change was expressed per minute of training, the two higher intensities were better at upgrading aerobic enzymes, even in the slow-twitch muscle cells, than the lower, traditional base intensity.
Note from this study that 38 minutes of running at 85 percent of O2max would produce a O2max upswing of 1 percent. To produce a similar change in maximal aerobic capacity, almost one hour of running at 70 to 75 percent of O2max would be required. If an athlete ran for just 20 minutes at 85 percent of O2max and for 40 minutes at 70 percent of O2max for a 1-hour workout, the upward movement on O2max would be 20 percent greater than running the whole hour at the slower intensity. It’s clear from such research that traditional base training is an inefficient way to build an aerobic base, that is, to expand O2max.
Running Science Page 35