Kyle Dalmau (B.Pod, MAPodA)
Running is fun. Well it should be!
As widely reported in the media, Eliud Kipchoge’s recent run in Vienna breaking the two-hour barrier for the marathon while wearing Nike Vaporfly next% shoe has created a lot of buzz and discussion. Internet forums and blog sites around the world are awash with information in the strategies elite athletes employ to better their performance. When concerning the long-distance runner, performance is often related to ones running economy. The Vaporfly shoe as an example has been shown to improve the running economy of its user by 4-5% in independent research. This has had a noticeable effect on running times, where in recent years both the men’s and women’s marathon record has been blown apart.
I believe it is great that events such as Kipoche’s run in Vienna has led to further attention and discussion regarding the use of technology in order to improve performance. At the elite level, where you would assume most athletes have access to the best training strategies and conditioning programs, it is looking like tech improvements in footwear is the next frontier.
Not many of us are going to have the privilege of having a purpose-built shoe – or in fact get access to the retail variation of the Nike Vaporfly shoe when it’s released. However, at the recreational to sub elite level, if improving your performance is one of your motivations in running, you may be missing one of the most accessible, yet effective interventions. Strength/resistance training.
At the sub-elite level, it is frequently observed that most middle- and long-distance runners do not partake in an effective strength training program and often do not engage any strength training at all. Many of you will understand the importance of resistance training (RT) for the prevention and rehabilitation of musculoskeletal injuries, but there is no doubt it is an underutilised modality to improve running performance (1).
An issue I often observe with runners, is that they love running, but only running.
Runners have traditionally feared strength training. One of most commonly reported reasons runners have abstained from RT, is the thought that heavy RT will slow them down, possibly due to the fear of ‘bulking up’. This belief has emphatically been proven to be incorrect within the literature. Many studies have shown that when RT programs are combined with existing running training, an improvement in running economy occurs without body composition changes (increase in muscle size) (2,3,4,5).
This article’s focus is to explain how neuromuscular traits can change following a period of RT and how this will improve your running performance through positive changes to running economy.
But firstly, I need to get some of the boring statistics and definitions out of the way. This content can be pretty dry, but for all you running nerds out there I hope it will enhance your understanding behind resistance training principles.
What is Resistance Training (RT)?
RT exercises are prescribed to move your body against a force. The force could be anything from your own body weight, gravity, TheraBand’s, gym equipment and free weights. Various methods of RT aim to induce several neuromuscular changes. The amount and how the force is applied will determine the outcomes of training.
Muscular endurance (END) exercises are prescribed with low or no weight, usually with many reps and often performed in a circuit.
Explosive (EXP) or plyometric training (PLY) usually have rapid movements such as jumping and hopping, performed with low to moderate resistance. PLY training will aim to improve the stretch shorten cycle (SCC) – more on this later.
Strength training or heavy RT involves moving a large resistance over fewer repetitions, with the aim to increase muscular power and strength.
What is Running Economy (RE)?
RE is measured by the amount of oxygen we use to maintain a steady velocity at submaximal running. It is one of the largest physiological determinants on running performance, even more so than maximal aerobic capacity (V02max) (6). Having a better RE allows runners with a similar VO2max to use less oxygen at submaximal running speeds, and thus reach and maintain a higher running velocity (2,7,8,9,10). RE is considered a ‘trainable’ factor that can be improved, usually without an increase to VO2max (7). Therefore, if we can improve our RE, that will ultimately contribute to a better running performance. For this reason, this article will relate the effects of resistance training on RE.
What are the physiological changes that will be induced following RT?
Runners of all abilities who aim to improve their running economy (RE) will see some improvement with each method of RT previously described. However, only following heavy RT do we significantly improve RE where it will aid performance (1,2,5). Some studies suggest heavy RT may be complemented by EXP and/or PLY training, particularly in well trained athletes (1,9,10,5,6). Muscular endurance (END) or cross training such as high intensity interval, or hill running, does not induce maximal activation of our muscles, and therefore neuromuscular change associated with improved performance is less likely to occur (11).
When combining Heavy RT or PLY training with existing running training, there will be neural adaptations within the muscle (without muscle hypertrophy), improving certain neuromuscular characteristics that aid running performance (5,10).
The improved characteristics see a change in the following:
Increased muscle-tendon stiffness
The role of tendons in running is to minimise the energy cost of muscle contraction (12). Energy demand during running is significantly related to the stiffness of the propulsive leg; that is, stiff tendons store and release elastic energy more efficiently (5). RT has been shown to increase muscle-tendon stiffness (1,4,5,12).
Better storage and return of elastic energy/Improved stretch shorten cycle
Elastic energy plays an important role on RE. It is estimated that oxygen consumption might be 30-40% higher without efficient elastic return (8,10). During the running gait, preparatory muscle activity at the leg and ankle occurs prior to footstrike, contributing to stiffer tendons absorbing elastic energy. As this energy builds during the braking phase of gait, efficient runners can return this energy effectively via elastic recoil, contributing to the force of propulsion. This rapid exchange of energy behaves much like a spring and is described as the stretch shorten cycle (SCC) (5,8).
Running is effectively repeated movements in the SCC. An efficient SCC delays muscular fatigue, as energy being returned elastically is generated with little increase to metabolic energy (oxygen consumption) (8). Superior athletes are thought to have proficient capabilities to the SCC, and this is also thought to be how they can tolerate higher loads demanded as running velocity increases.
Utilizing training principles to enhance the SSC is encouraged. Naturally PLY training is a method thought to exaggerate the SCC (7,8,9,13). However, some studies have compared the effectiveness of heavy RT vs PLY training on the SCC. Interestingly, the results would indicate that programs that predominantly focus on heavy RT have a greater influence on developing and improving movements that utilise the SCC (10,11).
Increased strength and power effects
With an increase to muscle strength and power, fewer motor units within the muscle are required to be activated to produce a given force. Runners with an increase to strength have a lower physical demand to their muscles and as such, have fewer motor units recruited per stride whilst running (4,5). This contributes to a superior running velocity and allows for a more powerful muscle group to be called upon for a sprint finish at the end of the race (2).
With increased power, another advantage is observed through better circulatory flow and oxygen consumption within the muscle. Shorter muscle contractions can produce enough force to maintain a certain running speed. The result is a gait with greater relaxation time within the muscle between each stride, therefore allowing more time for oxygenated blood to refill the muscle (4,5).
Central nervous system (CNS) changes
Interestingly, some research has suggested that fatigue is not only reliant upon physical muscular work, but also on the CNS’s ability to drive the motor neurons (4). They hypothesise that increasing muscular strength through RT not only results in a reduction of motor unit recruitment but may represent a more optimal activation of motor neurons.
Possible biomechanical changes
The benefits of RT could improve lower limb coordination to enhance biomechanical characteristics observed in high performance runners (e.g. muscle pre-activation for SCC). All runners will have their own individual biomechanical idiosyncrasies (where there are too many to mention in the confines of this article), however there are some common threads when assessing elite runners.
As an example, several biomechanical characteristics of elite runners may include shorter ground contact times, better transition from the braking phase to propulsion (SCC) and increased stride frequency (5,13). The combination of certain characteristics observed in elite runners is thought to generate a ‘sweet spot’ with a balance between running power and an economical gait.
For trained runners, their self-selected gait is usually very close to their ‘most efficient’ gait, so it would be unwise to make wholesale interventions to their gait, as RE would suffer. Novice runners can afford to make greater change without economy suffering. As RE is a ‘trainable’ parameter, subtle biomechanical changes over time could help in the process to improve RE in runners with less experience.
So now that we have discussed the physical adaptations that occur following heavy RT, lets discuss the principles of the training methods that will get you there.
What would my resistance training involve?
Firstly, like anything it is important to find the right balance. An individual’s training plan would also depend on several factors, including running experience, injury history and goals. I will not be able to cover specific examples of training exercises and dosage in this article, however some general advice on training methods will be outlined.
The main takeaway for the reader is that performing RT once a week is not enough to induce neuromuscular changes associated with an improved RE (1).
To safely improve RE, a RT program needs to consist of the following:
- 2-3 sessions per week
- 2-4 lower limb exercises per session
- Heavy resistance i.e. >70% 1RM(the load needs to be at 70% of your max effort for each rep)
- Single leg variations of exercises are best to complement running
- A range of single joint and multi-joint exercises can be helpful
- Plyometric exercises can also be used when appropriate.
- Weekly load should include an overall 3:1 endurance:resistance training ratio – for every 3 hours of running, 1 hour of RT.
Planning sessions around running events that require >90%VO2max (e.g. race day) is very important. In order to allow full recovery, and to be at your most efficient, it is recommended to perform any RT sessions a minimum of 24 hours prior to the event. For events and training sessions that don’t require maximal oxygen uptake (<90%VO2max), RT sessions will not impair RE (3).
How much will resistance training improve my performance?
Following a period of appropriate RT, RE can be improved by 6.5%-8.1%, without increasing running training volume – a superior effect when related to the Nike Vaporfly shoe (4,5,8,14). These results were demonstrated across many studies that either used heavy RT or PLY training over a period from 6-40 weeks. The improved RE allows athletes to reach a running velocity 14% quicker at their V02max (2). A 2.2-2.6% improvement in RE will produce direct performance changes to running times (8). Most studies have measured performance using time trials with distances ranging from 3-5km. Results would indicate a 3% improvement in times over these distances with as little as 6 weeks training, without changing running volume. Over the same period, control groups that didn’t do heavy RT and increased their training load by increasing running volume saw no improvement to their running performance (5). Additionally, when heavy RT training is reduced or ceased, a return to baseline pre-training levels of RE and other performance indictors occur (11).
This helps to validate the theory that ongoing RT is a vital part of a runner’s physical preparation. Although the improvements can be quite subtle, if performance is your main motivation to run, any advantage to run quicker should be explored.
The major take away for me regarding RT is the ability of runners to improve performance, without an increase to their running training output. “Runners love running and only running”, and therein lies the problem. The biggest risk towards injuries for running is running! If we do something too much, it can become harmful. Therefore, if we can achieve greater results without pushing running mileage to dangerous levels, risking overuse injury, it makes sense to train in a way that may result in less time lost through injuries and niggles whilst also improving performance.
As RT is commonly used in the prevention and management of musculoskeletal injuries, when you combine this with the more specific purpose to improve RE, theoretically you become an athlete who is able to train at a higher level for longer. As experienced runners are shown to have a superior RE, this may be because their training methods have allowed them to become more resilient to load and as such, have not missed large training blocks due to potential injuries.
In summary, numerous factors have been studied for their influence on RE and thus performance. Many interventions fail to have a positive effect on improving RE or are difficult to implement. As we all want to run better, faster and stronger, RT could be the most practical and effective tool to complement your running training. RT should not be feared and rather be viewed as a vital and ongoing component of a runner’s physical preparation.
Hopefully after reading this article you have learnt the following:
- Resistance training, when combined with existing running training, does not increase muscle bulk
- Improved neuromuscular characteristics increase muscular output during running, partly due to an increase to tendon stiffness, allowing for better recoil properties during gait (better springs)
- Resistance training improvements can be helpful to enhance running economy without an increase to running training volume
- Resistance training needs to occur at least twice a week to have an effect
- Best results were obtained using training methods that used heavy resistance
- Plyometric training can be used to complement heavy resistance training
- Results benefit runners of all levels
- Running economy returns to pre-training levels once resistance training has stopped
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If you would like to have your running gait assessed and learn about your running technique, economy and what we can do to improve it, I welcome you to visit the 3D RunLab at Melbourne Foot Clinic.
Whether you are a beginner, running for fitness or a seasoned veteran, running competitively, there is always room to improve. Having a 3D RunLab assessment, we can accurately record your running economy, biomechanical features and loading patterns with the statistics that contribute towards it.
The process will include a full Podiatric screening, instantaneous feedback on running form and retesting under different variables. A full report with test results and a recommended training/treatment plan will be emailed to you following the session.
References:
- Balsalobre-Fernandez, C; Santos-Concejero, J & Grivas, G. Effects of strength training on running economy in highly trained runners: A systemic review with meta-analysis of controlled trials. Journal of Strength and Conditioning research. 30(8):2361-2368. 2016
- Beattie, K; Carson, B; Lyons, M; Rossiter; A & Kenny, I. The Effect of strength training on performance indicators in distance runners. Journal of Strength and Conditioning research. 31(1):9-23. 2017
- Marcello, R; Greer, B & Greer A. Acute effects of plyometric and resistance training on running economy in trained runners. Journal of Strength and Conditioning research. 31(9):2432-2437. 2017
- Storen, O: Helgerud, J; Stoa, E & Hoff, J. Maximal strength training improves running economy in distance runners. American college of sports medicine. 40(6):1087-1092. 2008
- Barnes, K & Kilding, A. Strategies to improve running economy. Sports Med. 45(1):37-56. 2015
- Mikkola, J; Vesterinen, V; Taipale, R; Capostagno, B; Hakkinen, K & Nummela, A. Effect of resistance training on treadmill running and neuromuscular performance in recreational endurance runners. Journal of sports sciences. 29(13):1359-1371. 2011
- Moore, I. Is there an economical running technique? A review of modifiable biomechanical factors affecting running economy. Sports Med. 46(1):793-807. 2016
- Barnes, K & Kilding, A. Running economy: Measurement, norms and determining factors. Sports Medicine – Open. 1(8). 2015
- Turner, A; Owings, M & Schwane, J. Improvement in running economy after 6 weeks of plyometric training. Journal of Strength and Conditioning research. 17(1):60-67. 2003
- Saunders, P; Telford, R; Pyne, D et al. Short Term Plyometric training improves running economy in highly trained middle and long distance runners. Journal of Strength and Conditioning research. 20(4):947-954. 2006
- Taipale, R; Mikkola, J; Nummela, A et al. Strength training in endurance runners. International journal of sports medicine. 31(1):468-476. 2010
- Fletcher, J & MacIntosh, B. Running economy from a muscle energetics perspective. Frontiers in physiology. Open access published 22nd June, 2017
- Kyrolainen, H; Belli, A & Komi, P. Biomechanical factors affecting running economy. Medicine and science in sports and exercise. 33(8):1330-1337. 2001
- Paavolainen, L; Hakkinen, K; Hamalainen, I; Nummela, A & Rusko, H. Explosive-strength training improves 5km running time by improving running economy and muscle power. J Appl Physiol. 86(5):1527-33. 1999