If you visit the Kenyan National Training Camp, you will see the best athletes in the world running high mileage at high altitude. What you won't see is Moses Kiptanui or Delilah Asiago lifting weights. In fact, the Kenyans are so secretive in their iron-pumping that no one has ever seen them lift. Travel to Ethiopia, and you will see an equally impressive absense of muscle-building.
Here in America, however, weight-lifting or "resistance training" is part of the culture of sport. Go to the local health club, and half the place is devoted to chrome-plated "resistance machines". Football players lift weights. Hockey players lift weights. All-around jocks lift weights. To be real athletes, the logic goes, runners should lift weights too.
The question is, will weight-lifting improve your running performances? The following are the arguments for, and against, weight-lifting for distance runners.
Why you should lift
Weightlifting can correct muscle imbalances and prevent injuries. Resistance training will get your upper body in shape, which don't get much benefit from running, and will improve your core stability. Weightlifting can even improve your running economy, so you use less oxygen at a given pace.
Why you shouldn't lift
Weightlifting will make you muscle-bound, will add extra bulk that you will have to cart around, will tighten up your muscles, and leave you injured. You want to be the classic vertical hyphen, with no extra baggage. Bill Rodgers and Frank Shorter aren't the guys you call when you need help moving. Look on the victory stand at any of the major races, there's not a bulging bicep in the bunch.
Does weight training improve endurance performance?
A 1988 study by Dr. R.C. Hickson and colleagues at the University of Illinois at Chicago investigated whether adding strength training to an endurance training program would improve endurance performance. The investigators had 8 well-trained cyclists and runners add weight-training to their exercise programs. The subjects performed 3-5 sets of 4 leg exercises, 3 times per week for 10 weeks. Leg strength increased by 27% for parallel squats, 37% for knee extension, and 25% for knee flexion, over the 10 weeks. The weightlifting, however, did not result in any change in the subjects' maximal oxygen consumption (VO2 max).
Short-term endurance was measured by having the subjects cycle and run as hard as possible for 4-8 minutes. When re-tested after weight-training, the subjects had increased their time to exhaustion by 11% during cycling and 13% during running. Similarly, the length of time that the subjects were able to cycle at 80% of VO2 max increased from 71 minutes before weight-training to 85 minutes after weight-training.
The effect of the weight-training on the subjects' running performances, however, were less clear-cut. Two of the 8 subjects were injured from the heavy-resistance training, and were unable to complete the post-weight-training 10 K run. Of the other 6 subjects, their 10 K times improved from an average of 42:27 before the weight-training to 41:43 after weight-training. While this improvement was not statistically significant, it does suggest that the weight-lifting had some positive impact on running performance.
A 1995 study, published in Medicine and Science in Sports and Exercise, found similar results concerning VO2 max. Dr. John McCarthy and colleagues at the University of Wisconsin-Madison Biodynamics Laboratory, found no increase in peak VO2 with the addition of strength training to an endurance training program. In this study, sedentary adult males were divided into 3 groups. One group strength trained, a second group endurance trained, and a third "combined" group both strength and endurance trained. Peak VO2 on the cycle ergometer, increased by 18% in the endurance-trained group and by 16% in the combined group. Neither this study nor the University of Illinois study, therefore, found an increase in max VO2 or peak VO2 with the addition of strength training to an endurance-training program.
A 1994 study from the Department of Kinesiology at the University of New Hampshire, however, strongly supports weight-lifting for distance runners. Exercise physiologist Ron Johnston found improvements in running economy after a 10-week weight-training program. In this study, 12 trained female distance runners were split into groups for 10 weeks of training. The experimental (Run & Lift) group continued to run, and added a strength training regimen consisting of 14 exercises working the upper body, abdominals, and legs, 3 times per week. The control (Run) group just ran.
The Run & Lift group improved their upper body strength by 24% and leg strength by 34%. VO2 max and lactate threshold VO2 did not change in either group, which is consistent with the results of the studies already mentioned. The most interesting finding in the UNH study was that running economy improved significantly in the Run & Lift group, but did not change in the Run group. Running economy improved by over 2% at the 3 running speeds used in the study. Johnston explains, "Strength-training improves running economy either due to a reduction in wasted motion, or because stronger legs allow runners to rely more heavily on their more economical slow-twitch muscle fibers." Johnston is no idle observer of the sport, having won the 1994 Maine 50-miler.
Running economy determines how fast you can run at a given level of oxygen consumption. Since the amount of oxygen consumption that you can maintain during a race is determined by your lactate threshold, your running economy really dictates how fast you can race. An improvement of 2% in running economy translates to a 2% increase in race speed, which represents an improvement of 48 seconds for a 40 minute 10K runner!
Sounds great. Run and lift, run faster, and look good at the beach. But what if you'd rather listen to 24 hours of Ross Perot commercials than be forced to lift weights?
What if you hate to lift?
Try hill running. A 1985 study by Svedenhag and Sjodin suggests that similar improvements in running economy can be gained by running hills. In this study, 16 elite male runners improved their running economy by 1-4% per year through a combination of long-distance running, intervals, and hills. Other studies that included just long-distance running and intervals found no improvement in running economy, which indicates that the hills were what led to the improvements found in Svedenhag and Sjodin's study.
Running uphill requires that your legs propel your bodyweight up against gravity. Moreover, they do so under conditions that more closely replicate racing conditions than does even the most well-designed weight-machine. Anecdotal evidence for the benefits of hill running comes from the Kenyan and Ethiopian runners of today, and goes all the way back to the great New Zealand runners of the 1960's and 70's. The best runners in the world run hills day after day. Of course, there may be genetic factors that separate elite runners from recreational runners, but it certainly appears that hill training is an important element that, unlike your genes, you can change.
Another advantage of hill running over lifting weights is that you are simultaneously building up your cardiovascular system. Hill running, therefore, can be viewed as another form of resistance training. In this case, your bodyweight is the resistance. To improve your leg strength, you can perform resistance exercises by moving lead and steel in the weight-room, or you can perform resistance exercises by moving your entire body uphill against the force of gravity.
The evidence indicates that improving the strength of your legs through resistance training will improve your running economy. You can resistance train by lifting weights or running hills. If you decide to lift weights, get advice from a coach or trainer who understands that you are weight-lifting to improve your running, not to look like Arnold. If you decide to weight-train your legs, schedule your weight sessions so they are not right before or after a hard running workout. Regardless of whether you choose to hit the hills or hit the weights, your running economy and racing performances should improve.