Blog # 9 – The Demands of Running - Injury Prevention Series

Running is one of the most popular physical activities with over 620 million people participating in some form of running. Research shows that marathon participation has grown by 49% since 2008, while we are also seeing significant increases in the completion of 5km, 10km and half marathon races.

According to the Australian Sports Commission in the national sport and physical activity participation report in October 2023 participation levels within running remain higher than those recorded before the COVID-19 pandemic. There are numerous factors as to why this may be, but the most notable influence is the popularity of community focused run clubs which welcome in any level of runner.

For example, the Coogee Run Club in Sydney has grown to 2,500 members since its creation in 2022, emphasising the cumulative popularity in group-based running. Other factors would include social media and running apps like Strava and Nike Run club which create an environment for improvement and friendly competition. 

Running Reality

Whilst recreational running is enjoyable and has become increasingly popular, it has also attracted many less experienced/trained individuals. Therefore, its important to highlight potential injuries that may arise from running due to the repetitive demand and loads placed on certain structures. Running related injuries (RRI) can be as high as 73.9% (Van Gent et al, 2007). However, injury rates in runners vary by muscle group, with some areas being more prone to strain, overuse, and acute injuries depending on the type, duration, volume and intensity of running being performed.

Typically, lower leg injuries to the calf, achilles and shin make up 50-75% of running related injuries, whereas knee injuries (20-30%), hip/glute (5-15%) and core/low back injuries (5%) are less frequent. However, as started the type of running activity will impact the loading parameters of muscles, tendons and joints. For example, sprinting 100m is vastly different to a marathon runner and thus the speed of muscular contractions and loading of structures are vastly different.

Nevertheless, all types of runners can mitigate the likelihood of injuries and improve their running performance via two consistent features:

1. Strength and resistance training

2. An effective pre-run warmup/preparation protocol

Running Demands

Duration and running distance (5ks to marathons) generates a range of forces through various muscles, tendons and joints. Slower running has been shown to generate peak ground reaction forces of 6.7 x BW (bodyweight) in the soleus, a major contributor of propulsion during sustained running.

Additionally, other important musculature such as the glute medius, a muscle responsible for pelvic stability and weight transfer takes up to 4 x BW. The patellofemoral joint can take up to 5.2 x BW whilst lower limb tendons including the patellar and achilles can take up to 5.5 and 6-7 x BW, respectively (Lenhart et al., 2014, Almonroeder et al. 3013, Hart et al., 2022).

Interventions

Consequently, this highlights the need for muscles, tendons and joints to be strong and capable of producing large amounts of force but also have the capacity to endure repetitive forces for long durations. Enter - resistance training! A strength training program alongside your running is vital for mitigating injury risk due to improving the bodies capability to handle more stress and load (force).

Research has shown that integration of strength training programs can reduce the risk of overuse injuries by up to 50% (Lauerson, 2013). Additionally, strength training can be beneficial for improving bone density which helps to limit the potential for bone stress injuries. Bone health is a concern for runners who experience and accumulate a large amount of running volume each week.

Strength training helps target the bones that experience repetitive forces in runners such as the lower body (knees, ankles, hips, spine) to become more conditioned to handle repeated stress. This is achieved by directly and mechanically loading critical areas (lower limb, spine) through a variety of intensities and volume which stimulates bone remodelling and increases bone mineral density (BMD).

Therefore, its evident runners should include resistance training into their weekly training routine for enhanced performance and reducing the risk of injuries.

Other strength training benefits include:

• Improved muscle imbalances

• Improved joint stability

• Improved flexibility and elasticity

• Increased force production and absorption capabilities

• Increased muscular endurance

• Increased power output capability

• Increased tendon stiffness

Moreover, heavy resistance training 80%> of maximal voluntary contraction (MVC) can improve running efficiency and performance, particularly when performed with plyometrics (Lkanos-lagos et al, 2024). A systematic review of 24 studies concluded that strength training enhanced running efficiency by 2-8% and time trial performance by 2-5% (Blagrove et al. 2018). A more economic runner will be able to produce and transmit forces more evenly thus being faster and more durable whilst also reducing the potential of overuse.

Lastly, runners should incorporate a dynamic pre-run warmup protocol before each and every run they complete. A suitable warmup has many scientifically backed benefits that helps to improve performance through physiological and neuromuscular priming.

Some major benefits include:

1. Increased blood flow & oxygen delivery – warmups gradually increase the heart rate and dilates blood vessels which improves blood circulation to working muscles, an increased oxygen supply helps reduce fatigue of muscle fibres thus enhancing performance.

   
   

2. Improved Muscle Temperature & Elasticity – Enhanced elasticity decreases risks of ligament and muscular strains. A warmer muscle relaxes and contracts more efficiently leading to more economic mechanics and movement strategies.

   
   

3. Mobility and joint lubrication – Reduced friction/stiffens with increase of synovial fluid production, whilst increased joint mobility improves stride and running efficiency 

   
   

4. Activation of the Nervous System – priming the central nervous system (CNS) helps with quick coordination and reaction times and overall psychological readiness. Neuromuscular activation or firing helps with recruitment of muscle fibres which improves running economy and performance.

   
   

5. A steady Heart Rate and Breathing Increase – a gradual warmup will allow for a controlled raise in heart rate and breathing minimising a spike in blood pressure, dizziness and distress.

   
   

6. Decrease in Lactic Acid Buildup – a controlled increase in intensity improves muscled ability to clear lactic acid more efficiently thus delaying the onset of fatigue and a more sustained performance

   
   

Evidently, a dynamic warmup is an effective protocol in minimising the potential risks of injury whilst also being a performance enhancer. Skipping a warmup can have detrimental effects in terms of movement efficiency, performance outcomes, muscle function, stiffness and increased chances of an injury occurring.

Conclusion

Running has become increasingly popular but it does not come without its injury risks due to its large repetitive force demands and volumes. Therefore, here at Rehab Advantage we recommend runners to incorporate strength and resistance training alongside effective dynamic warmups to not only counteract these injury risks but to actually seek improved running economy and performance outcomes.