Before beginning, I must mention that my current thoughts on strength training for endurance athletes have been built on an understanding of exercise physiology that’s largely been shaped over the years by a dude named Jamie Scott — he’s got an awesome blog discussing many aspects of human health.
Now, onto talking about the subject at hand. Find me a runner, and 9 times out of 10, you’ve just found somebody that doesn’t lift weights.
I see it all the time, like there’s a choice one has to make between being a runner or lifting weights. I’m sure the 9/10 is an exaggeration, but even so there are far too few people that engage in running as their form of training that don’t completely neglect strength training. They’ll dabble in some high rep resistance training on their “off-days” because they’ve read somewhere that they should, but it’s rarely given a serious consideration as a part of one’s routine.
There are many reasons why a runner might not want to strength train (I think they’re all BS), and it’s pretty obvious that the way most people go about recommending strength training for runners is a waste of time — which doesn’t help convince them to do it.
I think that lifting weights is an important aspect of training for all people, and this includes those that enjoy running. I’m going to try and look at things from a different perspective and shed some light on this much-debated subject: should runners lift weights?
What makes somebody good at running. There are a few things that instinctively come to mind when we think of a good runner, of course, but there’s also a lot of things that most people would never think about. In this part of the series, I’m going to talk about a few of the things I think make up a good runner, and how strength training would affect all of those things either positively or negatively. Basically, the purpose of this part is to determine whether or not strength training would be good or bad for runners. Let’s go.
Often touted as the king of endurance characteristics, the maximal oxygen consumption is basically the amount of oxygen that can be used during exercise, and is important because our muscles need high amounts of oxygen during intense activity in order to sustain their performance. If we cannot deliver a high amount of oxygen to our muscles during intense work outputs, then they will not be able to work very hard for very long periods of time.
Our muscles obtain energy either aerobically (with the use of oxygen) or anaerobically (without the use of oxygen). It takes longer to produce ATP (energy) from the aerobic metabolic pathways than it does to produce ATP from anaerobic pathways, and so whenever our requirement for energy exceeds our ability to effectively transport oxygen, we move to primarily using anaerobic pathways because they are faster. The importance of understanding this lies with the inefficient production of ATP via anaerobic glycolysis, in that the chemical reactions that take place to convert carbohydrate to ATP without the use of oxygen will end up producing lactic acid. When lactate levels in the muscles become too high, beyond our capacity to metabolize it, it contributes (along with many other things) to muscular fatigue.
This is why we cannot run our 400m sprint pace for 5km — we cannot produce energy anaerobically for long enough. This is why having a higher VO2max can help us run faster for longer periods of time — it allows us to transport more oxygen to our muscles, making the intensity at which we switch over to anaerobic metabolism higher, delaying the point at which our muscles become fatigued.
As long as we have known that VO2max was an important indicator of whether or not a person would be able to perform an endurance activity well, it has been known that the highest VO2max values don’t necessarily represent the best endurance performers; but it is a determining factor in the maximum intensity that a person can perform.
Unfortunately, there is no good evidence to suggest that strength training could improve one’s VO2max in this recent review nor otherwise that I could find.
I’ll give Strength Training a 0 for this category, because although there were no specific improvements in VO2max from strength training, there were no negative outcomes that could be found either.
Lactate threshold is the point at which lactate begins to accumulate in the blood of an athlete — when we starts to produce energy anaerobically. If a person’s lactate threshold is higher, then that person will perform at higher intensities before lactate accumulates in the blood; which means that they are able to go faster whilst still producing energy aerobically, allowing them to move at a higher intensity for longer periods of time than someone with a lower lactate threshold.
Most of the training involved with improving our lactate threshold is going to be from endurance-type training and not from strength training.
We can, however, improve our power output at the lactate threshold from strength training! A quote from the above-mentioned review:
Numerous studies report a high relationship between long-term performance and velocity/power output at the lactate threshold in… running…”
So although there’s probably not a whole lot that strength training can do to improve our lactate threshold, it can make us stronger allowing us to exert more force whilst at our lactate threshold, which allows us to move faster at that intensity.
I’ll give Strength Training a +1 for this category.
Fairly self-explanatory, this is how fast a person can run. Numerous factors will come into play that are involved with the speed at which a person can run, and especially so when discussing longer distances. But very simply in order to run faster we must produce more power.
The muscle-fiber type that produces more force are type II muscle fibers, compared to type I muscle fibers. Strength training will increase the composition of type II fibers (even the oxidative ones) in endurance athletes, according to this paper.
Strength training will also increase our ability to fully recruit muscle fibers thanks to the neuromuscular adaptations involved with strength training, which allows us to produce more force and will help to improve our performance in addition to the fiber-type changes. More neural recruitment of our muscles and stronger muscles make us run faster.
Another +1 for Strength Training.
There’s no doubt that being able to exert a great deal of force is required in order to perform well, and most people understand that in order to be fast over distances they must be strong in relation to how much they weigh. More force generation with less weight to move is a bonus for these type of activities. Most, however, will focus more on their weight than on their strength, and attempt to simply lose weight/be as light as they can. This is one of the main excuses I see for endurance athletes to avoid taking up strength training — fear of gaining weight.
If we’re trying not to put on a bunch of muscle but find that the program we’re following has us doing so, then perhaps we’re simply following an inappropriate program. Though it’s probably important to keep in mind that any extra weight we may put on (to a certain point) will come with an increase in force production, negating the gained weight’s negative outcome.
As I mentioned above, many of the increases in strength from lifting heavy things will come from adaptations of the nervous system, and may not even involve building muscle; and when it does involve building muscle, it doesn’t necessarily have to be a lot of muscle.
Resistance training is also an important part of losing fat, and so it can improve our strength-to-weight ratio both my increasing strength, and by decreasing weight (if we have fat to lose).
Another +1 for Strength Training if you ask me.
Efficient Fuel Usage/Storage
The ways that we can produce energy are as follows:
CREATINE-P <—> Creatine +P <—> ATP
GLYCOGEN <—> Lactic acid +P <—> ATP
GLYCOGEN —> P —> ATP
FATTY ACID —> P —> ATP
As you can see, we are able to use glycogen (aka stored carbohydrate) to produce energy both with and without oxygen, and are only able to use fatty acids to produce energy when there is oxygen available. Since there are probably going to be times during an event that require us to produce energy anaerobically, I think it makes sense to want to spare glycogen (since we have a limited storage capacity) for such times. Increasing our storage capacity for glycogen and becoming able to use less of it so that we have more glycogen available for when it’s needed is a major goal of improving fuel usage/storage.
The parts of our muscle cells that actually take in fats and carbs to produce energy are called mitochondria. Different types of muscle fibers will have different amounts of mitochondria, and different capacities for storing and using both glycogen and fatty acids.
Type I muscle fibers have lots of mitochondria, a great capacity to store triglyceride (storage form of fatty acids), and a very high oxidative capacity. They are the most fatigue-resistant muscle fiber.
Type IIa muscle fibers have a decent amount of mitochondria as well, a much larger capacity for glycogen storage, and a relatively high oxidative capacity. They are very fatigue-resistant and can produce high amounts of force.
Type IIx muscle fibers have a poor mitochondrial density and oxidative capacity, and are very quick to fatigue, storing mostly glycogen and creatine-phosphate. They are powerful, but short-lasting.
Ensuring efficient use of fatty acids in the oxidative muscle fibers will help to spare glycogen (not specifically related to lifting weights). Increasing the amount of type IIa fibers will help to store more glycogen (lifting weights can do this). Increasing the amount of type IIa fibers in proportion to type IIx fibers can help spare glycogen (lifting weights can do this).
Something that’s probably mostly overlooked regarding strength training is that increasing strength can decrease the number of activated muscle fibers that are required to produce the same force as a weaker fiber. If I can deadlift 300lbs, deadlifting 160lbsx10 will recruit less muscle fibers than it would if I was only strong enough to lift 200lbs. According to a 1994 paper, increased maximum strength reduces the amount of activated muscle mass required to generate the same absolute submaximal power. Weak muscles work harder to do what strong muscles can do easily.
Let’s think about what this may mean for endurance training and fuel usage. This would mean that a submaximal effort (running) will be using less muscle fibers. With less muscle fibers being used, this could mean that less energy is required at a certain pace for somebody that is stronger compared to somebody that is weaker. Sounds like a great way to save energy — get stronger! Through this mechanism, it could also theoretically delay fatigue by sparing muscle fibers, in addition to creating a higher proportion of the more fatigue resistant type 2 fibers that was mentioned above.
Definitely going to attribute another +1 to Strength Training for this category — more fuel storage, less fuel usage.
So it would seem that without even discussing the numerous benefits of strength training for general health benefits, or even for injury prevention, there is a case for taking it up if you are a runner solely for the potential increases in performance since 4/5 of the categories of performance I brought up can benefit from strength training.
Hope this helps to clear up some of the discussion.
Next comes the what to do, and the how to do it.