Wednesday, 26 August 2009
Resistance training for runners Part 1.
If you are looking for a simple list of the best exercises that you should do then stop reading now. If you want to understand in more detail the loads the legs are placed under when we run and how different exercises have different affects on the body and through that learn the types of exercises that will best improve your running performance then read on.
Resistance training for runners can have many benefits. Increased leg strength and endurance means our legs can tolerate more load ( running either faster or for longer), tolerate the demands of running downhill more effectively, increase power to run uphills, decrease our risk of injuries, strengthen our tendons and ligaments and improve our running efficiency to name a few.
To get the most out of resistance training the exercises performed should place the body under similar loads as running does. One of the key principles to resistance training is the SAID principle. - Specific Adaptation to Imposed Demands. What this means is the body will adapt to whatever training load ( imposed demand) you put on it by becoming more efficient at performing that particular task (specific adaptation). Each exercise we perform in the gym involves a complex series of muscular contractions throughout the whole body. Every exercise is different and the brain remembers what combination of muscles it has to activate and what forces it has produce to perform the exercise more efficiently next time. If we are training for a specific function i.e. running then it makes sense that we should ensure that the exercises we select place the body under as similar load to running as possible.
I often hear people say that certain exercises really burn their thighs so it must be a good for runners. Unfortunately this is far from the truth. Resistance exercises work the legs without doubt but that's where the similarities with running end for many of them. I know what you are thinking. “Surely resistance training which uses leg muscles must help our legs become stronger for running? They are not that different activities?” This depends on the type of resistance training and sometimes it can actually make you weaker for running not stronger.
Another key principle to consider is the difference between movement type muscles and stabiliser muscles. Some muscles in our body are designed to make us move and others are designed to keep our joints stable whilst we move. If our movement type muscles place our joints under more load than the stabilising muscles of our joints can handle then we end up injured. The brain tries to prevent this by decreasing the amount of force our movement muscles can produce. An easy way to understand this is think about how fast you can run on the track compared with running on a rocky undulating surface. On the rocky surface our brain knows our ankles are struggling to remain stable so it will decrease the amount of force the movement type muscles in our legs can produce which means we run slower.
If the stabilising muscles are weak then often the brain will try and make the movement type muscles try and act more as a stabiliser . So now you have the muscles that are responsible for moving you as quickly as possible as trying to stabilise you as well. The result is you tire more easily. If you can increase the strength of the stabilising muscles you allow the movement muscles to get on with the task of moving your limbs as fast as possible.
To understand which exercises are best for running we first need to understand the loads placed on our body when we run. We can then select particular exercises that emphasise these loads. There are three main points to consider.
1.Running is a one legged activity.
Running by definition involves one foot being off the ground at all times. What this means is that when we land we have to stabilise the foot, knee, hip, pelvis and spine against the landing forces of with one leg not two. We also have to stabilise the non landing side of the body against the forces of gravity. For example when we land on one leg, gravity continues to act on the other side of the body causing it to drop. The muscles on the landing side of the body have to control that drop so you don't end up swaying side to side.
So you can immediately see that any exercises done with two feet on the ground ( or machine) is not going to place the body under a similar load to running. The muscles that control the gravitational force on the other side of the body wont have to perform any work at all as there is no force on that side since the leg is already on the ground. So what do you think will happen to those particular muscles? Well if they are not being placed under any load then there is no stimulus to become stronger and if they are not needed then they will become weaker.
Let me be very clear on this point so there is no confusion. Doing 2 legged exercises will make the muscles that stabilise your body when on one leg WEAKER.
2.Running involves landing on one leg.
The biggest load on the body when running is the one that occurs when we land. This seems obvious but how many exercises in the gym do you see involving landing on one leg? Standing on one leg and squatting up and down is not the same as the foot is already on the ground.
3.Muscles have more strength when they are lengthened and loaded first.
To illustrate this point try this simple test. Stand up and then jump. Now try and and jump a little higher. What you will have noticed is the first movement you made to jump up was to squat down. When you tried to jump higher you would have squatted lower. Why would you squat lower when the aim is to jump higher?
By squatting lower you increase the length and load on the big muscles of the hip which are responsible for jumping, allowing you to jump higher.
Think of trying to fling a rubber band , the further back you pull the band the further forward it flys. The tendons and ligaments in your legs operate in much the same way. The more they are stretched under load the more power they have when released. The good news for runners is gravity can provide this load so we effectively recieve energy for free.
A good example of this is the Achilles tendon. As we land our lower leg continues to travel forward which places a stretch and load on the calf muscles and Achilles tendon. The Achilles stores this energy which is then released as our calf muscles contract and we push off the ground.
All the muscles in our legs operate in the same manner. As we land our leg muscles have to prevent our leg from collapsing into the ground. The muscles act as a breaking force against gravity. This obviously happens at speed and takes less than 0.5 of a second. During this process muscles are loaded and lengthened which is then released as we drive off the leg.
This is why good runners make running look effortless. They are actually putting in less effort than slower runners because they have become very efficient at loading and unloading their muscles..
Hopefully you can now understand that running is the process of landing on one leg, decelerating that movement by loading and lengthening the muscles in the leg and then pushing off again.
Lets now look at the different types of leg exercises commonly used in the gym and see if they are of any use to the runner.
Leg Press, Leg Curl , Leg Extension
Exercises such as leg press ( lying on your back pushing a weight with your legs) , leg curl (lying or seated curling your legs behind you) and leg extensions, (sitting straightening your legs in front of you) are all of very little value as they are all in a seated or lying position. This means all the hip, knee,foot and core muscles that are involved in supporting you when you stand on one leg don't have to work at all.
Yes these exercises might make your legs stronger and you might feel it burn in all the right places but that's not the point. Does it load your muscles in a similar way to running? The answer I hope you can see by now is a resounding NO. The likely result from doing these type of exercises is stronger movement based muscles and weaker stabilising muscles. This translates into weaker legs for running as your movement based muscles now have to take on the role of stabiliser muscles as well. A job they are not designed to do.
When choosing leg exercises ELIMINATE any that involve lying or sitting down using a machine. Remember by doing these types of exercises you are likely to make your muscles LESS able to handle the demands of running.
There are many different versions of the squat and done correctly even a two legged squat can be of some benefit. Particularly using it as an initial exercise to build strength for the more useful running exercises.
The obvious problem is squats are normally performed on 2 legs which negates the use of all the stabiliser muscles in the hip, feet knees and core.
The second problem is that when squatting we control the descent, typically taking 1-2 seconds. When we run the descent takes less than 0.5 of a second.
The third problem is when we squat our feet are already on the ground so we don't have to deal with the landing forces that occur 90 times a minute on each leg when we run. Whether squatting is done with a bar, dumbbells, bodyweight or ball behind your back it should only ever be done as a means of developing initial strength in your legs and hips. If you've been running for a while you'll have this already and should choose a more relevant running exercise.
One legged squats are obviously are better option than two legged as at least we have to involve the stabilising muscles of the hip, knee, foot and core. But even 1 legged squats miss out a crucial ingredient of a good running exercise. There are no landing forces involved as our feet are already on the ground.
The lunge is a much better option. For starters it looks similar to running with one leg forward and one leg back. If we start with feet together and step forward landing on one foot we have to deal with the landing forces as our foot hits the ground. The landing is relatively quick so simulates a similar load to running. The foot, knee, hip and core muscles all have to work to stabilise the body as we land. One of the down sides is the action of pushing back to the start position. During running we push forward not back.
This is the same as a normal lunge except instead of pushing back we continue forward. This is resembles running even more so but it still has it's limitations. The landing force is on one leg but the other leg is still on the ground so the landing forces and the stabilisation load on the opposite side of the body aren't as high as it would be during running. Another problem is when we land we typically land on our heel when we lunge ( or walk) whereas when we run we should land on the mid foot or toes ( see http://andydubois.blogspot.com/2009/06/running-heel-to-toe-in-supportive.html)
This involves starting in a lunge position and then jumping in the air and swapping legs over so you land on your other foot. This is a more dynamic exercise that increases the speed of the landing and therefore increases the landing forces. It also allows you to land on your toes so makes for an excellent exercise for runners. The deeper you go when you land the more the muscles of the hips and thighs are loaded.
Skipping and Jumping
Skipping and jumping are particularly useful for training the calves and the Achilles tendon. Deeper jumps can also effectively load the big muscles of the hips. Although landing on two legs there is still significant landing forces ( particularly when jumping higher and or longer distances) involved . Jumping and skipping make an excelletn introduction into one of the best exercises for runners.
Bounding is basically running but with REALLY long strides. The longer stride means increased landing forces and therefore greater demand on the leg hip and core muscles. Very effective exercise for runners.
Hopping is even more difficult than bounding as you hop from one leg to the same leg rather than landing on the other leg as you do when you run or bound. Landing forces are higher than for running. This is the ideal scenario. To be able to replicate running in the gym with an increased load so when you run outside it feels easier.
I have listed these exercises from easiest to most challenging and I would recommend most people start with Lunges and progress to walking lunges, jump lunges, jumping, bounding and finally hopping.
In part two of this article I will discuss running as a three dimensional activity. We think of running as a one directional activity ie. We run in a straight line. Our body direction might be in a straight line but every joint in our body is moving in three different directions at once. By adapting our exercises to load in each of these directions we can make our resistance training exercises even more effective.