TrainingConverting Science into Performance |
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Does Strength Training Improve Running Performance?
Should runners strength train? Will weight lifting make you a faster runner? Will it protect you against injury? These questions come up often and each time they do it sparks considerable debate as to whether resistance training provides any benefit to runners. In this article we will examine the available research to see if we can find some answers to the above questions. Strength training, Weight training, or Resistance Training? Sometimes people have different meanings for common terms. For example, do the terms strength training and weight training mean the same thing? The answer depends on how you define the terms. For example, some may define “strength training” as resistance provided by any method – free weights, exercise machines, body weight, etc. Others may define the term “strength training” to mean resistance training with resistance provided by something other than barbells, dumbbells, or machines. Push ups, chin ups, and hill running would be examples. So, you see, it depends on how you define the terms. However, no matter how you define the terms, the exercises all serve the same purpose – to increase muscular strength and/or power. For our purposes, we will use the term “resistance training”. Resistance training is any training designed to increase muscular strength and/or power. It does not matter what provides the resistance to the muscle – free weight, machine, body weight, etc. As long as the exercise is designed to provide resistance to the muscles with the intent of increasing strength and/or power, it is resistance training. Research There has been surprisingly little research on the effects of resistance training on endurance athletes that has actually studied changes in performance. Quite a few researchers have examined changes in physiological variables from resistance training, variables such as lactate threshold, running economy, or VO2max, but few have studied actual changes in performance as a result of added resistance training. The general assumption of these researchers has been that improvements in VO2max, lactate threshold, or running economy are indications that performance has also improved. However, that may not be the case. It could be that these variables improve with no corresponding improvement in actual performance. Conversely, these variables might not improve, yet endurance performance could improve. Generally speaking resistance training has been shown to increase VO2max, lactate threshold, and running economy in untrained subjects. In trained subjects, resistance training has only been shown to improve running economy. Based on these results, it is tempting to say that resistance training is a benefit to all endurance athletes. To be definitive though, we must examine changes in performance from resistance training and not just use the traditional markers of endurance as proxies for performance. When research actually examines changes in endurance performance, a slightly different picture emerges. Of the research that has studied changes in performance, the results have been less clear cut. Let’s take a look at just those studies that have evaluated changes in performance regardless of any changes in traditional physiological endurance markers. Table 1 is a summary of the studies I am aware of that compared changes in performance as a result of resistance training. Table 1: Research on the effects of resistance training on endurance performance
Notes Study 1: Significant increase in short term cycling and running performance (47% and 12% increase respectively) Study 2: Subjects were endurance trained and were at a steady-state level of performance. Significant improvement in both short and long term cycling performance (11% and 20% respectively). Significant improvement (13%) in short term running performance. 10k time was inconclusive because 2 of the 8 subjects were unable to complete the 10k run due to injury. However, 10km running improved by 43 seconds in the remaining 6 subjects (improvement did not reach a level of significance). Study 3: Slight increase in power output during one hour cycling test (did not reach a level of significance). Also, Bishop and Jenkins conducted a second study (6) of the effect resistance training had on critical power and time to exhaustion in untrained subjects that showed no improvement in performance. I don’t have access to this study and don’t know enough of the details to comment on it or include it in table 1. Study 4: Improved cycle time from 26:18 m:sec to 35:06 m:sec - an 8:48 m:sec or 33% improvement Study 5: Replaced 32% of run training with explosive strength training consisting of various sprints (5-100m) and jumping exercises (with and without added weights), and leg press and knee extensor-flexor exercises performed at high or maximal velocities. Significant improvement in 5-km performance. Discussion While more research needs to be conducted on this topic, the available research does provide some training guidance. First, note that at no time has the addition of resistance training had a negative impact on endurance performance. It either has a neutral or positive effect. The study by Bishop (and possibly a second study by Bishop, ref.6) showed no change in endurance performance when resistance training was added. Conversely, in the other four studies endurance performance was enhanced by the addition of resistance training. Of particular interest is the study by Paavolainen, which replaced 32% of endurance running with explosive strength training. Despite a 1/3 decrease in volume of training, 5k performance improved in elite runners with the addition of resistance training. The conclusion that can be drawn from these facts is that resistance training won’t hurt endurance performance, but is very likely to improve performance. Second, resistance training affects shorter distance/time performance more than it does longer distance/time performance. The addition of resistance training caused an improvement in short term endurance in each study that examined short term endurance. Medium distance performance was also improved by the addition of resistance training; the study by Marcinik (4) showed an improvement in medium distance performance (30 minutes) and Paavolainen’s study showed improved in the 5k. On the other hand, the two studies that evaluated longer distance performance (ref. 2 & 3) had mixed results. One study showed a 20% improvement in long distance cycling and one showed no significant change in cycling performance. 10k running time improved by 43 seconds in trained endurance athletes, but the improvement did not reach the level of significance. The conclusion we can draw from these results is that as the competitive distance increases, resistance training has a decreasing effect. Resistance training is likely to have a much more pronounced effect on running distances less than 10k than it does on performance at distances beyond 10k. It is also possible that resistance training has a greater effect on cycling performance than on running performance, but more research must be done before this conclusion can be safely drawn. The third thing, and I would add that it’s not fully represented in the research referenced in table 1, is that resistance training likely has a lesser effect on well trained or elite athletes than it does on untrained or novice athletes. Presumably this is because there is simply less room for improvement in athletes who are much closer to their genetic limits than those who are untrained or only lightly trained. Though the improvements may be too small to verify via scientific study, they can be significant to the individual athlete. For example, while a 43 second improvement in well trained runners who have reached a performance plateau was not large enough for it to reach a level of significance (ref. 2), it is still a considerable improvement to those athletes and could play a major factor in finishing results. Another example would be the outstanding performance of Paula Radcliffe in 2003. She set world records at the 5k, 10k, half-marathon, and marathon and credits her world record performances to the addition of strength training (7). Her improvements, though large enough to propel her from world-class to world’s best, are not large enough such that in a research study they would be considered to be at a level of significance. Summary While there has been considerable research on the effects of weight training on endurance performance, there has not been a large amount of research that has actually measured changes in performance when resistance training is added to an endurance athletes training program. Generally those research studies that have examined markers of performance such as VO2max, lactate threshold, or running economy find that weight training is a benefit to endurance athletes. Research that evaluates actual performance changes supports this view and indicates that resistance training is likely to improve performance, especially at running distances of 10k and less. As the competitive distance increases it is likely that resistance training has a decreasing effect on performance. Considering all the data, my recommendation is for the addition of 1-2 days per week of resistance training to your training program, especially if you typically compete at distances of 10k or less. Bonus Section – Why? For those who want to explore a bit further, this section delves into the reason why resistance training improves endurance performance. References:
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