Muscles make up more than 40 percent of an individual’s body mass, even in the thinnest of distance runners (Fahey, Insel, & Roth, 2011). Muscles consist of individual muscle fibers connected in bundles. This number of fibers is inherited, meaning it cannot be changed through training. It is the number of muscle fibers that allows some people to look “ripped” without even trying, while others may try effortlessly with little change. Thus, a person’s somatotype (or physique) is relatively stable and difficult to change. Although the number of muscle fibers is stable, the size of each muscle fiber can change. As a result of strength training, individual fibers increase the number of myofibrils, resulting in hypertrophy (muscle growth).
Due to genetic and hormonal differences, men are typically capable of building more muscle mass than women, but both genders make about the same percent gains in strength through a good training program. But is strength training necessary for long distance runners? Are the risks of injury worth the cost? These are just some of the questions as many coaches and runners are hesitant to engage in formal strength training programs.
THE IMPORTANCE OF STRENGTH TRAINING
Most people hold strong views regarding the importance of strength training for distance runners. Opponents to strength training argue that the relative risk of injury outweighs any benefit—and that running alone is enough. Because strength training for distance runners is a controversial issue, it is worth discussing. While strength training does not necessarily improve a runner’s ability to use and deliver oxygen (a key predictor of distance running performance), evidence shows it should be included in any competitive distance running program.
Although strength training should never come at the expense of running training, it does improve distance running performance and prevent injury more than running alone. Injury rates among runners are extremely high, with rates varying from 2.5 to 12.1 injuries per 1000 hours of running (Van Mechelen, 1992). Most running injuries are lower extremity injuries, frequently the result of muscular imbalance which can be prevented through strength training. The point is that, contrary to popular belief, strength training rarely results in injury for most distance runners. Van Mechelen also reports about 50 to 75% of all running injuries appear to be overuse injuries due to the constant repetition of the same movement. One of the most effective means for minimizing tissue trauma associated with distance running is to develop stronger muscles, tendons, fascia, ligaments, and bones. This is the primary reason that every runner should perform regular strength exercise. Strength training contributes to prevention of shin splints, stress fractures, lower back discomfort, knee problems, and hip injuries common to distance runners. Greater muscular strength decreases the risk of joint injury or overuse strain by minimizing connective tissue stress (bone, ligament, tendon, or cartilage), which plays a part in maintaining joint integrity (i.e., durability).
In addition to its role in important aspects of injury prevention and athlete preparation for the upcoming more intense training, strength training can have a beneficial effect on distance running performance, especially through an increase in running economy and neuromuscular characteristics, including motor unit recruitment and ground contact time. In middle and long distance running events, increases in speed are produced by an increase in stride length. This is the result of applying more force during foot contact rather than increasing stride frequency. Runners who are capable of keeping consistent running mechanics (i.e., with the lowest decrease in stride length) are those who are able to sustain competition speeds for longer time periods. Thus, strength and plyometric training exercises improve force production and stride length.
There is a great deal of evidence that explosive plyometric strength training improves running economy and muscle power and that running training supplemented by strength training are better than running training alone. Spurrs, Murphy, and Watsford (2003) observed a 2.7% improvement in 3K running performance following six weeks of plyometric training in conjunction with participants normal running training, while no changes in maximal oxygen consumption (VO2 max) were recorded. Paavolainen, Hakkinen, Hamalainen, Nummela, & Rusko (1999) observed an average 3.1% improvement in 5K running time for well-trained athletes in a 9-week study. These improvements are thought to be the result of neural adaptations without observable muscle hypertrophy. Therefore, it appears strength training programs for distance runners must meet two requirements: (1) include full-range, running-specific movements for the prime movers and (2) emphasize training the stabilizers.
PERIODIZED STRENGTH TRAINING
Periodized training programs in general are overall more effective than non-periodized training programs for increasing maximal strength. However, less is known regarding the effects of periodized strength training on the performance of trained endurance runners. Periodization is the gradual cycling of blocks of time in which specificity, intensity, and training volume are varied to achieve peak levels of fitness. Periodized running-specific strength training minimizes the loss of stride length that typically occurs in endurance runners during fatiguing bouts (Esteve-Lanao, Rhea, Fleck, & Lucia, 2008) and is therefore recommended for all competitive distance runners.Strength training for the runner can be divided into three phases: pre-competition, competition, and off-season. During these periods, the volume and number of sets performed changes to meet the different seasonal demands of a running program.
The greatest benefits of strength training for distance runners should be gained during the pre-competition period. Volume should be the highest during this time of year, which compliments the lower intensity of running. When trying to increase strength maximally, a protocol of three sets per exercise (with about a two minute rest between sets), and five to six repetitions per set has been shown to be effective for most athletic populations. A common mistake for distance runners is that they do not challenge themselves appropriately, typically avoiding heavy workloads in the weight room. Determining the amount of weight to use is somewhat a trial and error process. The last repetition should feel as if you couldn’t do another. If your last repetition seems easy, add five to ten percent more weight. Total body training two to three times a week during the pre-season will suffice, giving adequate time for full recovery after workout.
The competition period for most runners comprises the portion of the year where you are racing the most. The goal of this in-season strength training period is to maintain as much strength as possible. In-season lifting mainly requires one or two weight-training sessions per week with only one or two sets of eight to ten repetitions per exercise. Since weight training should never take place at the expense of running training, avoid overtraining by limiting the number of sessions to two days per week, limiting the training load—and avoiding strength training all together the last 3 or 4 weeks of the competitive season.
For competitive runners, the off-season period starts when your racing season is over. The first four weeks of the off-season serve as a time to recover both physically and mentally. During this time, weight training can be performed two times a week consisting of only one set of eight to 12 repetitions of each exercise with adequate rest periods between sets. After four weeks of recovery, increase your weight training volume to two or three sets of each exercise, with 60- to 90-second rest intervals as you also begin to increase running volume.
The nature of running creates muscular imbalance (e.g., strengthens quadriceps, neglects hamstrings) and inflexibility. To counter the effects of distance running, running-specific strength training is necessary. Muscles that are trained through a full range of motion are simply stronger and more flexible than those that are not. The stabilizer muscles are the small muscles responsible for balance and posture (lower back, gluteal, and hamstring muscles). Most distance runners are not strong enough in their core to excel in their sport. This is unfortunate because the stabilizers and postural muscles are the first to fatigue in a race or training. Once the stabilizers fatigue, the effect is a slight breakdown in running mechanics and a loss of efficiency.
Be prepared for the biggest moments by mastering the small ones off the field.