Running is a hugely popular sport with millions of athletes across the world clocking up miles each week in pursuit of adventure, fitness and freedom. One of the challenges associated with it however is to remain robust enough to withstand its repetitive loading, in order to mitigate injury risk whilst maximising health and performance.
A common myth in the running community is that simply running by itself is enough when it comes to planning a training programme. This article aims to highlight the benefits of strength training and how it can benefit runners of all levels.
Why do injuries happen?
In simple terms, an injury in the body occurs when the demand placed on it outstrips the capacity of the body to deal with the demand. Demand can come in the form of magnitude, frequency, density or volume of load. A good example would be a runner completing a weekly running volume that they are unaccustomed to, and much greater than they had completed in any previous weeks. The body will undergo stresses that it is not prepared for, which it would have been had the increase in running volume been more gradual. Overuse injuries such as medial tibial stress syndrome or a form of tendinopathy can occur in this scenario, amongst a range of other possible injuries.
The solution therefore is to try to bring our capacity as close to or above the demands that we are likely to encounter during running.
Why is strength training important?
This is largely where strength training comes in for a runner. Due to the high volumes associated with the sport, the ability to tolerate these loads is paramount if a runner is to remain injury free. Strength training increases the amount of force that our tissues can both tolerate and express, whilst improving our running economy. If we can produce greater forces, we can operate at a lower percentage of our maximal output. An analogy here is to imagine ‘raising the ceiling’ of a room.
As well as this, research has consistently demonstrated that strength training can improve neuromuscular efficiency, lactate threshold and muscle power. This means that you can expend less energy and run faster when you need to. Long story short, the benefits are significant and become even more impactful the less experienced with strength training that you are. This is because the body will adapt more quickly to a new stimulus that it is unaccustomed to - great news! This should provide some reassurance if the idea of strength training is a little intimidating for you.
The following section will provide some insight into the muscles that are heavily involved in running, and how we can strengthen them to enhance running performance and overall health.
Soleus
The soleus muscle is the major force producer of the lower limb, contributing up to 8 times body weight of force (a lot!) during high speed running. This is largely due to its large cross sectional area (size) and orientation of its fibres. Combined with the calf muscle, it exerts force on the Achilles tendon in order to produce mechanical power during running. Given its significance in running propulsion, it often gets neglected in strength training programmes however. That’s a lot of untapped potential!
As it is a uni-articular muscle (it only crosses one joint), it is trained most effectively in positions of knee flexion. Exercises such as seated and bent knee calf raises are the good options, using a high volume approach to loading. This is primarily due to its high proportion of slow twitch muscle fibres, which makes it relatively resistant to fatigue. An example could be 3-4 sets of 15-20 repetitions on a seated calf raise machine.
Glutes and Hamstrings
The hamstrings are a key muscle group in running due to their importance in both hip extension and knee flexion. Developing strength and capacity in these muscles is vital to ensure that they can attenuate the high forces experienced during running (particularly when running downhill). A combination of hip extension exercises (single leg romanian deadlifts and hamstring bridges) and knee flexion exercises (nordic curls and leg curls) will bulletproof them against load related injury. The glutes act as the primary hip extensor and therefore have a central role to play in running propulsion. Exercises such as hip thrusts are the best way to target this powerful muscle group.
Single leg exercises
Owing to the fact that running is a cyclical, unilateral movement pattern we should prioritise single leg exercises when designing a strength programme for runners. This allows us to address any imbalances that may exist between our legs that may contribute to injury risk, whilst also enabling heavier loads to be lifted. Due to something called the bilateral deficit, we can lift more on one leg than we can with 50% of the load on two legs. For example, if we can squat 60kg, we will be able to single leg squat more than 30kg. This means that we get more load out of our strength exercises, which is more good news.
Single leg exercises can be hip or knee dominant in nature, so it’s vital that we address both. Hip dominant exercises such as single leg romanian deadlifts are great as they challenge balance and proprioception in the foot/ankle whilst also providing a strength stimulus for the hamstring through large ranges of motion through hip extension. Knee dominant exercises such as high step ups challenge hip and ankle range of motion whilst developing strength of the adductors which stabilise the pelvis and knee.
Adductors
As already described, the adductors stabilise the pelvis and knee. They have an important role to play therefore in upright running, and weaknesses to this muscle group can lead to injury in the knee. Strengthening them through positions of deep hip flexion such as wide stance split squats and high steps ups, in combination with copenhagen variations is the best way to provide a well rounded strength stimulus for this muscle group.
Tendons
Our tendons act as springs in order to transfer and recycle forces. Their viscoelastic qualities mean that they can exhibit viscous (stiff) or elastic (springy) characteristics depending on the mechanical stress that they undergo. Generally speaking, the faster that we run, the more elastic in nature our tendons will become, meaning that our muscles act isometrically to enable lengthening of the tendon and the muscle-tendon unit. The slower we exert force from a muscle, the greater the force we produce and the less elastic the tendon behaves. This is due to something called the force-velocity relationship of muscles. At slow contraction velocities, such as lifting heavy loads, our muscles are able to produce high amounts of force. Conversely at fast contraction velocities such as when we lift light loads, they are unable to do so.
If we want to increase the stiffness of the tendon, which will allow us to produce greater forces at the ankle joint, then heavy load isometric exercises are a great way to achieve this. For example, this single leg isometric exercise is a great way of achieving this outcome by providing a high load stimulus in relevant joint angles associated with running. Use a thick band to provide sufficient resistance, pushing hard for up to 5 seconds at a time.
If we want to increase tendon elasticity, then plyometric exercises can achieve this, as the tendon behaves more like a spring. You should be sure that you have developed a foundation of strength prior to this, but this type of exercise can provide a lot of value for runners. Exercises such as pogo jumps are a great way to develop the elasticity of the Achilles tendon. Aim to complete 3 sets of 10-12 repetitions.
Trunk
The muscles of the trunk act to stabilise the spine during running and prevent rotation that can cause unnecessary losses of energy. Our lateral trunk in particular plays a key role here, and therefore needs supplementary strength exercises to support running posture and mechanics. For our lateral trunk muscles (including our obliques), exercises such as side plank variations and lateral trunk holds are a great way to develop their capacity.
For our anterior trunk (front of the trunk), exercises such as single leg lowers, plank variations and isometric holds are good options. All trunk exercises should be completed at high volume and frequency, as this is what the trunk needs to develop its tolerance to loading.
Range of motion
The capability of each joint for active and passive range will have implications in other parts of the body. For example, if the ankle joint is limited in dorsiflexion (toes to shin), then it is possible that an athlete will rely on inversion (rolling) of the ankle to achieve the desired range. This will put greater stress on passive tissues and structures, increasing the risk of injury. As stress is related to the surface area over which it is applied, the greater the area that we can dissipate forces over the lower limb, the less joint stress we will experience.
The answer therefore is to ensure regular mobilisation of the key joints involved in running, including the ankle and hip. This can be achieved through stretching, soft tissue therapy and strength training through full ranges of motion.
How often should I be strength training?
As a ball park, runners should aim to complete some form of strength training 2-3 times per week in order to safeguard their bodies against injury. This is because it is difficult to include a running programme on top of a strength training programme given most people’s constraints such as work and other commitments. This does differ depending on the stage of the season, and if you are a competitive runner then you can ease off the strength training volume around important races to maximise recovery and freshness.
Loading
As endurance running has been shown to interfere with the adaptations from strength training, it is very difficult to gain much muscle size from doing so. This is a common concern amongst runners who are understandably keen to maintain a low mass to increase efficiency. With that in mind, runners should try to utilise relatively heavy loads to complement the overall training plan. More endurance work here is not the best solution, as this will be more than covered from the running being completed each week (dependent on weekly volume). Aim to use 5-8 repetitions on strength exercises (other than the calf, soleus and trunk) with no more than 2 reps left ‘in the tank’ after you’ve finished your set.
Example strength training session for a runner
This session is completely out of context, so is by no means right for everyone. However, it hopefully pulls everything together to provide an example of how a strength training session could look for a runner.
1) Mobility sequence targeting all of the key joints mentioned in the article (10 minutes)
2) Pogo jumps 3 x 12 reps
3a) High box step ups 3 x 6-8 reps each leg
3b) Standing calf raise 3 x 15 reps each leg
4a) Single leg romanian deadlift 3 x 6-8 reps each leg
4b) Seated calf raises 3 x 20 reps
5) Trunk circuit (aim to complete 8-10 minutes of total work)
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References
Beattie, K., Kenny, I. C., Lyons, M., & Carson, B. P. (2014). The effect of strength training on performance in endurance athletes. Sports Medicine, 44 (6), 845-865.
Bohm, S. Mersmann, F. Santuz, A. Arampatzis, A. (2019) The force–length–velocity potential of the human soleus muscle is related to the energetic cost of running. Proc. R. Soc. B. 286, 2560.
Ellis RG, Sumner BJ, Kram R. (2014) Muscle contributions to propulsion and braking during walking and running: insight from external force perturbations. Gait Posture. 40(4): 594-9.
Hamner, S. R., Seth, A., & Delp, S. L. (2010). Muscle contributions to propulsion and support during running. Journal of biomechanics, 43 (14), 2709–2716.
