Strength Training Repetitions – How Many Reps and How Much Resistance for Distance Runners?
There has been a theory around for many years called the strength – endurance continuum. Basically this theory is a scale starting with one repetition of the most weight you can lift (1RM or 1 rep of maximum weight) that progresses to many repetitions of a lighter weight. The logic behind the strength – endurance continuum is that performing 1RM will maximize strength gains and performing many reps of a very light weight will maximize muscle endurance. As you increase your number of repetitions and decrease the weight you improve your muscle endurance gains and decrease your strength gains. So how many reps should you do?
There have been many studies over the years that have proven that theory to be true. Doing just a 1 to 5 reps of a very heavy weight will maximize your strength gains while doing 20 or more reps of a lighter weight will maximize your muscular endurance gains. At first glance it seems obvious that doing just a few repetitions of a heavy weight is the way to go for strength gains. After all, that’s the goal of strength training – right? In my opinion, maybe not.
Don’t forget that you are performing strength training to improve your performance as a runner, not simply to improve your overall strength. Building up a lot of strength isn’t going to benefit you much as a runner if it doesn’t help you meet your running goals.
So what’s the matter with building strength? Won’t strong muscles make you a better more powerful runner? The answer to that is yes – if you build that strength in the right way. In order to make your strength gains beneficial to you as a runner they must be highly specific to your running movement patterns. The closer your strength training mimics your running movement patterns the greater the benefits you will reap as a runner. You need to build not only strength, but more importantly power. In physics text books, power is defined as “the time rate of doing work”. For our purposes as distance runners power more specifically refers to your ability to produce force at high speeds. In simple terms a high degree of power will allow you to produce a large amount of force in a very short amount of time – a perfect situation for building your running speed and efficiency.
It’s that very definition of power that presents a basic problem to distance runners when performing high weight low repetition strength training. Lifting heavy weights requires relatively slow muscle contractions which is in direct opposition to the rule of specificity that says your training should mimic your goal – in your case the many very fast repetitions of running. It is also in opposition to the definition of power which places a great deal of emphasis on the speed of your repetitions. For those reasons I am convinced that performing a high number of repetitions of a more moderate resistance level is more appropriate for a distance runner.
Is there any data to support my opinion? Yes there is. A study performed by the Department of Biomedical Sciences at Ohio University investigated the response of athletes to three different resistance training routines using leg press, squat and knee extension exercises.. The researchers divided their volunteers into four groups – a low repetition group, an intermediate repetition group, a high repetition group and a control group that did no strength exercises. The low repetition group did 4 sets of 3 – 5 reps with 3 minutes rest between sets. The intermediate group did 3 sets of 9 – 12 reps with 2 minutes rest between sets. The high repetition group did 2 sets of 20 – 28 reps with 1 minute rest between sets. The scientists monitored maximal strength, local muscle endurance, maximum oxygen consumption, maximal aerobic power and time to exhaustion both before and after 4 weeks of the routines.
As expected the low rep group showed the most increase in maximal strength. Of most interest to runners were the results that showed only the high repetition group showed significant increases in maximal aerobic power and time to exhaustion. In other words, only the high rep group showed improvements that would help them as distance runners. Another important factor in strength training for distance runners in avoid excessive hypertrophy or increase in muscle size which would cause some weight gain. This same study showed that “the low to intermediate repetition resistance-training programs induced a greater hypertrophic effect compared to the high repetition regimen.” The researchers went on to conclude that “The High Rep group appeared better adapted for sub maximal, prolonged contractions, with significant increases after training in aerobic power and time to exhaustion.”
Again, in my opinion, backed up by scientific data, a distance runners strength training routine should be composed of mostly high repetition – low to moderate resistance exercises. That doesn’t mean that you should never perform the low to moderate repetition – high resistance exercises. There are always times when you may need to maximize your strength gains or build lean muscle mass. During those times the low rep – high resistance regimen may be the way to go. But for general running performance and power increases I think you would see superior results with a high rep – low to moderate resistance routine.
Muscular adaptations in response to three different resistance training regimens: specificity of repetition maximum training zones, Eur J Appl Physiol. 2002 Nov;88(1-2):50-60.