Do Runners Need to Strength Train?

 

I was having a conversation with someone tonight at the track after the San Diego Track Club workout, and she brought up strength training as a way to become a better runner. This is not the first time someone has tried to convince me that runners need to strength train. I have written and spoken extensively about this. I, and many other coaches who have come before me, starting with Arthur Lydiard in the 1950s, believe that runners can get a lot more out of running hill sprints or bounding up a hill than by doing lunges while holding dumbbells. Rather than repeat what I already have written, here, in its entirety, is one of my articles on the topic, reprinted from Running Times magazine.

When I was in eighth grade, I broke the school record for chin-ups. I still have the certificate of achievement from the school’s principal proudly displayed on my wall. I still brag about the accomplishment to others. It doesn’t matter that it was so many years ago or that some tough kid has probably come along since to break my record. At the time, I had the strongest biceps and forearms in junior high. I used chin-ups to show off to the girls in class. My mother even bought a chin-up bar and attached it to my bedroom doorframe so I could train at home. I did chin-ups every day. Until I became a distance runner.

At first glance, distance running doesn’t seem to have much to do with big, strong muscles. Indeed, the best runners in the world are quite small, with slim legs and arms that would make actress Lara Flynn Boyle drool. But, as I tell my athletes, it’s not what your muscles look like; it’s what they do that matters. And, if trained properly, muscles can be taught to do some amazing things. Just ask the Kenyans and Ethiopians with the skinny little legs.

These days, athletes in all sports lift weights to supplement their sport-specific training. Even distance runners have jumped on the bandwagon. Indeed, much has been written about strength training for the runner—everything from lunges while holding dumbbells in your hands to calf raises on the edge of a stair to endless repetitions of abdominal crunches while balancing on a big, lime green exercise ball. Does anyone else listening to these training suggestions ever wonder if they will really lead to a new 5K or marathon personal best?

My research on the training characteristics of the 2004 U.S. Olympic Marathon Trials qualifiers, published in International Journal of Sports Physiology and Performance in 2007, found that these marathoners do little, if any, strength training. During the year of training leading up to the Olympic Trials, the men averaged less than one strength workout per week and the women averaged 1.5 strength workouts per week. About half of the athletes did not do any strength training at all. One of two conclusions can be drawn from this—either the U.S.’s elite marathoners do not believe that strength training will make them better marathoners, or they do not have the time to strength train given the time they devote to running. 

Why Strength Training Won’t Make You Faster

Unlike most sports, which require strength, speed, and power to be successful, distance running performance is primarily limited by the delivery and use of oxygen. There are no studies showing that strength training improves oxygen delivery from lungs to muscles, which is largely dictated by your athletes’ cardiac output (the amount of blood pumped by the heart per minute), their muscles’ capillary and mitochondrial volumes, and many other physiological traits. Oxygen wouldn’t recognize a dumbbell if it were hit on the head with one. The physiological changes resulting from strength and endurance training are also contradictory. For example, when the volume and intensity are high enough, strength training stimulates muscle fiber hypertrophy (growth in muscle size). This may increase body weight, which increases the metabolic cost of running. Larger muscles also have a smaller density of capillaries and mitochondria, which is detrimental to endurance. It is well known that endurance training causes muscles to respond in an opposite fashion by increasing the number of capillaries and mitochondria to facilitate the diffusion and use of oxygen. Endurance training also decreases body weight, optimizing oxygen use. Contrary to strength training, which has a “pressure effect” on the heart, endurance training has a “volume effect” on the heart, increasing the size of the left ventricle so it can eject more blood (and oxygen) with each beat.

Despite the different physiological adaptations between strength and endurance training, many runners still lift weights, typically with light to moderate loads and a high number of repetitions, programs that are geared toward increasing muscular endurance (the ability to sustain or repeat a submaximal force) rather than strength (the maximal amount of force muscles can produce). But is performing a few sets of 10 to 20 repetitions going to increase muscular endurance over and above what you already achieve from your weekly running or what you would achieve by running more miles? Think about how many repetitions you perform while running just 5 miles. Surely a mere 20 to 60 reps extra in the gym is not going to make you faster. While some studies have found that this type of strength training may help inexperienced runners who have a low fitness level improve their performance, other studies have shown it to be ineffective. Traditional strength training also may not benefit experienced, highly-fit runners and may even hinder them, especially if it is performed at the expense of more sport-specific training. The fact is that most runners, unless they are highly-trained and have maximized their running training, don’t need to strength train to improve their distance running performance. A 20-minute 5K runner is better served by improving the cardiovascular and metabolic parameters associated with endurance than by strength training.     

Why Strength Training May Make Your Faster

Sometimes, science can be a tricky business. Although the value of strength training to improve distance running performance is not readily apparent, it may help you to become faster if done with the right type of program. That’s because increasing your muscular strength will increase your muscular power, which is the product of force (strength) and speed. Athletic performance is ultimately limited by the amount of force and power that can be produced and sustained. Force and power are influenced by a number of physiological traits, including neuromuscular coordination, skeletal muscle mechanics and energetics, efficiency of converting metabolic power into mechanical power, and the skeletal muscles’ aerobic and anaerobic metabolic capacities. 

Most movements in sports occur too quickly for muscles to produce maximal force; it is far more important to increase the rate at which force is produced. For example, while racing, your feet are in contact with the ground for only a fraction of a second, not nearly enough time to generate maximal force. The goal of strength training is to get your muscles to increase their rate of force production, so you can have stronger muscle contractions in a shorter time. Also, by increasing muscle strength, you will reduce the percentage of your maximal strength required for each contraction during running, delaying the recruitment of fast-twitch muscle fibers and the associated inevitable fatigue. This is where strength training comes in. Research suggests that strength training, when geared toward training for power, has some value for endurance athletes. Maybe the football player and the distance runner have something in common after all. Interestingly, power training has been shown to improve running economy, which is the oxygen cost of maintaining a given pace and is one of the three major players affecting distance running performance (the other two are VO2max and lactate threshold). 

Maximal/Explosive Strength Training

Recent studies have shown that running economy is improved when subjects include explosive or heavy weight training in their training programs. Two studies, one published in Scandinavian Journal of Medicine and Science in Sports and the other in Medicine and Science in Sports and Exercise, had their subjects perform lower body exercises using heavy weights (greater than 85% of one-rep max, the maximal amount of weight that can be lifted once) with fast speeds for 3 to 4 sets of 5 to 6 repetitions. Other studies have used 3 to 5 sets of 3 to 5 reps to muscular failure with greater than 90% one-rep max. In addition to improving running economy, the subjects of these studies got stronger without gaining weight. Admittedly, this type of strength training, which may be intimidating at first, is likely different from what runners have been told to do in the past. Unlike a muscular endurance training program, which incorporates many repetitions of a moderately light weight, lifting very heavy weights will overload the force-producing characteristics of muscles. Because of its strenuous nature, you should work with a partner to help you determine your one-rep max for each exercise and do the workouts together. Since heavy weights can’t be moved very quickly, focus on contracting your muscles, making sure you move the weight safely with proper form.

Plyometrics

Contrary to heavy weight training, which focuses on the strength component of power, plyometric training focuses on the speed component. Plyometric training, which includes jumping and bounding exercises involving repeated rapid eccentric and concentric muscle contractions, has also been shown to improve running economy. Muscles produce more force during the concentric (shortening) contraction if the contraction is immediately preceded by an eccentric (lengthening) contraction. In a study from the Australian Institute of Sport, a group of highly-trained runners that added nine weeks of plyometrics to their running training improved running economy and leg power more than did a control group that only ran. In another study from Finland published in Journal of Applied Physiology, one group of runners combined endurance training with plyometric exercises (5 to 10 reps of 20- to 100-meter sprints and jumping exercises) and lower body weight training with light weights (0 to 40% one-rep max) lifted quickly, while another group did only endurance training. Only the runners who did both the plyometric and endurance training improved their economy and 5K time.

None of the above studies using either heavy weights or plyometrics found changes in other cardiorespiratory measures important to distance running, such as VO2max or lactate threshold. This is an important finding because it suggests that the improvements in running economy do not result from cardiovascular or metabolic changes, but rather from some other mechanism. When lifting maximal weights (strength component), or when performing quick, plyometric movements (speed component), you recruit a lot of muscle fibers, which serves as a training stimulus for the central nervous system. The result is that the muscles increase their rate of force development, getting stronger, quicker, and more powerful, without the negative side effect of increasing muscle size. The more effective muscle force production translates into better running economy. While all runners can certainly benefit from an improved economy of movement, only a couple of studies have actually measured whether racing performance improved after power training. These studies found that performance did improve, using either a 3K or 5K time trial. The muscle power needed for these short distance races, which are run at or close to VO2max, is important. However, it is unknown whether power training will improve performance for longer races, such as the marathon.

If you’re planning on adding weight training to your program, periodize your annual training plan to circumvent the abovementioned incompatibility between strength and endurance training. Use specific periods of the year during which you focus on either endurance or strength/speed/power. Do the bulk of your strength training during your speed phase of training rather than during your aerobic endurance phase, since speed, strength, and power are more closely related physiological traits than are strength and endurance. Likewise, do your strength/power workouts on your speedwork days rather than on your recovery run or long run days.

If you have already increased your running volume and intensity as much as you can, or if you cannot handle the physical stress of running more miles, power training with weights and plyometrics may be the next step in your training program. And if you train hard enough, maybe you’ll even be able to break my middle school chin-up record.

 

 

 

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