The Science of Running
- Running is an individual and complex task that comprises three main factors; cardiovascular fitness, strength/capacity and motor skill.
- Cardiovascular endurance is important in both short distance and long distance running.
- Strength is an important component of running and various major muscle groups have high loads that they need to withstand as running speed increases
- The high demands of hip flexors, hamstrings and glute max as running speed increases to sprinting
- The importance of soleus in the calf complex for all speeds of running
- Exercise selection can be used to help target muscle groups to get the most out of your strength training
- Motor skill is important in coordinating the way you run
- Video analysis is great way to measure and observe motor skill and can be carried out to help understand whether your running gait may be affecting your performance or injury
Running is an incredibly individual and complex task that has been an important form of movement for humankind. It has been an important part of survival, fitness and the foundation movement for many forms of sports. Running mechanics and gait analysis has been a topic of conversation for many years. As technology and sports performance has improved over the years, the use of 3D biomechanics, electromyography (EMG) testing and force plate testing has catapulted running mechanics to a new level. Since the COVID lockdown, we have had an influx of recreational and amateur runners all around Australia. This is a beautiful thing. However with the increase in running, comes the increase in injuries.
This article will hopefully explain the basics of running and give you an appreciation of the demand that running takes on your body. To begin with, the diagram below illustrates the three main components that need to be considered in running.

Cardiovascular fitness is an important component for any form of running, whether it be sprinting, or long distance running. The ability for your heart to circulate blood to your major muscles and extremities is crucial to running well. One of the key measures that we can use to gauge how hard a running session is using your heart rate. With almost everyone using high tech watches, this is an extremely useful tool to measure your running progress and the intensity of your sessions.
Strength and capacity is perhaps the foundation of being able to perform any complex task. Running is a highly demanding activity that requires the activation and force production through multiple muscle groups in sequence to help you move forward. There are two factors that matter the most when running:
- Stride Length
- Stride Frequency.

The Dorn (2012) article had nine individuals whose peak muscle contributions were measured during different speeds of running. The graphs below help paint a picture of the different demands on the major lower limb muscle groups that increasing running speed had on the major muscle groups of the lower limb.
These graphs can be quite confusing to understand but the vertical axis represents the force measured relative to each individual’s bodyweight. For example, if there is an athlete with 100 kilograms in weight and they were running at 8.99 m/s (34 km/h) you are expecting to get 9 times the body weight instantaneously through the hip flexor muscles and hamstring muscles. That is equivalent to 900 kilograms of force that would load through the hamstrings of that specific athlete at that running speed. Hopefully, one can appreciate the strength and force demands that muscles in the lower limb require to be able to stay functioning and uninjured with complex demands.
Furthermore, you can see the high demands of hip flexor and hamstring muscles as running speed increases. It is no surprise then that hip flexor and hamstring injuries tend to be the most common amongst high speed athletes (Danielsson et al., 2020)

(Dorn, Schache & Pandy, 2012) Image source: (Sendic, G – Kenhub)
The quadricep muscles tend to have a lot of loading through all speeds of running but there is a clear increase in rectus femoris muscle demands with increasing running speed. This also makes sense as the rectus femoris muscle crosses both the hip and knee.

Finally, the last graph demonstrates the high loads through the calf complex as running speed increases and more importantly it puts a spotlight on the soleus muscle. The soleus muscle is typically not known to the general public and is under-appreciated in strength training. It is a powerful flat muscle that sits underneath the gastrocnemius muscles and generates more than 3 times the amount of force compared to the gastrocnemius muscles. The soleus muscle is more targeted with bent knee calf exercises and is crucial to power generation in all speeds of running.

So what does all the data mean to you?
It means that we have a good estimate of the baseline strength values that muscle groups need to have. It is important to remember that the peak force numbers are instantaneous and we are not going to do a hamstring curl at six times your body weight. However, we have a good idea of what muscle groups to target with your strength training and what numbers you need to achieve. Below are electromagnetic graph readings of different exercises and how much activation you get in various muscle groups.

Soleus electromyography (EMG) activation through different exercises (McCullough, n.d.)
Gastrocnemius electromyography (EMG) activation through different exercises (McCullough, n.d.)


Hamstring EMG activation during lower body resistance training exercises (Ebben, 2009)
Quadriceps EMG activation during various exercises (McCullough, n.d.)


Glute maximum EMG activation with various exercises (Collings et al., 2023)
Glute medius EMG activation with various exercises (Collings et al., 2023)

Disclaimer: These exercises are not the only exercises that can be done to help with building strength and there is a lot more involved in the delivery of these exercises through a quality training programme, quality of technique and exposures through the week. Furthermore, the accuracy of this data needs to be validated but it is a good starting point.
Finally, the last component of running involves the coordination of all of these movements together to help produce an efficient and repeatable pattern that a runner can maintain over a long period of time.
This is the skill acquisition component running that is developed through coaching, practice and consistent running.
Part of assessing the skill component of running is what we aim to measure and assess at South Melbourne Physio. The running assessment service looks to analyse your running pattern and assess any motor control deficiencies and compensation strategies that you may have. These strategies may be relevant to any performance or injury that you may have. However, it is putting all three of these factors together to help you figure out what you need the most.

It is important to highlight that not everyone needs a running assessment. In fact, there are plenty of individuals who are able to run pain free with minimal interventions. Running injuries are a whole different topic that have multiple factors that influence them. Running technique is only the tip of the iceberg but often it is a great way to identify where the iceberg might be.
In conclusion, running is a highly complex task that involves a careful balance of your cardiovascular system, strength, endurance and motor control. There is a lot of information out there on the internet about running styles, technique, strength training and injury management. Our aim will be to provide evidence and practice based information to inform you about what to consider. We are aiming to provide more articles on strength training with running, recovery strategies and load management.
If you need any help with your running or are experiencing an injury related to your running please contact us at South Melbourne Physio.
Keep Moving.
Yomi
References
Cleveland Clinic Medical. (2021). Quad muscles: Function and anatomy. Cleveland Clinic. https://my.clevelandclinic.org/health/body/22816-quad-muscles
Collings, T. J., Bourne, M. N., Barrett, R. S., Meinders, E., GONçALVES, B. A. M., Shield, A. J., & Diamond, L. E. (2023). Gluteal Muscle Forces during Hip-Focused Injury Prevention and Rehabilitation Exercises. Medicine and science in sports and exercise, 55(4), 650–660. https://doi.org/10.1249/MSS.0000000000003091
Danielsson, A., Horvath, A., Senorski, C., Alentorn-Geli, E., Garrett, W. E., Cugat, R., … & Hamrin Senorski, E. (2020). The mechanism of hamstring injuries–a systematic review. BMC musculoskeletal disorders, 21, 1-21.
Dorn, T. W., Schache, A. G., & Pandy, M. G. (2012). Muscular strategy shift in human running: dependence of running speed on hip and ankle muscle performance. The Journal of experimental biology, 215(Pt 11), 1944–1956. https://doi.org/10.1242/jeb.064527
Ebben W. P. (2009). Hamstring activation during lower body resistance training exercises. International journal of sports physiology and performance, 4(1), 84–96. https://doi.org/10.1123/ijspp.4.1.84
Hébert-Losier, K., Wessman, C., Alricsson, M., & Svantesson, U. (2017). Updated reliability and normative values for the standing heel-rise test in healthy adults. Physiotherapy, 103(4), 446–452. https://doi.org/10.1016/j.physio.2017.03.002
McCullough, T. (n.d.). Training the Lower Body . Training the lower body: The quadriceps. https://www.texaspowerscene.com/articles/bodybuilding/quadriceps.html
Schache, A. G., Brown, N. A., & Pandy, M. G. (2015). Modulation of work and power by the human lower-limb joints with increasing steady-state locomotion speed. The Journal of experimental biology, 218(Pt 15), 2472–2481. https://doi.org/10.1242/jeb.119156
Sendic, G. (2023, October 30). Iliopsoas muscle. Kenhub. https://www.kenhub.com/en/library/anatomy/iliopsoas-muscle
Sendic, G. (2023, October 30). Gluteal muscles. Kenhub. https://www.kenhub.com/en/library/anatomy/gluteal-muscles
Sendic, G. (2023, October 30). Posterior thigh muscles. Kenhub.
https://www.kenhub.com/en/library/anatomy/posterior-thigh-muscles
Wikimedia Foundation. (2023, December 4). Triceps surae muscle. Wikipedia. https://en.wikipedia.org/wiki/Triceps_surae_muscle