Running economy (RE) refers to the energy demand for a given running velocity, and improvements in RE mean an athlete can go faster or further with less energy demand. RE is therefore a crucial determinant of endurance performance and team-sports performance (1-3). In the context of team sports, having a better running economy is important considering the large running distances that many athletes cover during a game at submaximal speeds (e.g. 8-12 km for soccer players (4); ~8 km for elite Gaelic football players (5); ~13 km for elite Australian Rules football players (6, 7)). For athletes involved in sports requiring multi-directional speed, such as soccer, basketball, or tennis, optimising RE is thus crucial not just for (repeated) straight-line sprinting but also for (repeated) change of direction performance.
While most research on RE focuses on endurance running, the principles can be applied to any sport where efficiency of movement is key. In this blog I will therefore delve into the relationship between running technique and RE, based on the findings of a recent very comprehensive review (2) and additional recent papers on this topic (8, 9). I will also discuss practical applications, including exercises to potentially enhance RE, making this an actionable guide for athletes and trainers.
Understanding Running Biomechanics and Running Economy
Running biomechanics encompass the movement patterns (i.e., kinematics) and forces (i.e., kinetics) involved in running. This includes joint angles, spatio-temporal characteristics such as ground contact and flight times, and muscle activation. The systematic review and meta-analysis I recently did with colleagues highlighted several key biomechanical factors that influence RE, and offered insights into how small adjustments in technique may lead to improvements in running economy and thus potentially athletic performance (2).
The most important findings of this review are shown in Figure 1. I will summarise the key findings in the sections below, and thereafter discuss some potential implications. In brief: The review revealed that lower vertical displacement and higher leg stiffness are positively correlated with better RE. Essentially, minimising unnecessary “up-and-down” motion and maximising the elastic return of energy from the tendons can help conserve energy. Joint angles, particularly at the knee and hip, also play a role in the energetic cost of running; more optimal angles such as less knee flexion during swing and stance may reduce the metabolic cost of running.
k = number of effect sizes for the specific outcome.
Figure adapted from (2).
Spatiotemporal outcomes
Spatiotemporal outcomes such as ground contact time, flight time, and duty factor (i.e., ground contact time relative to stride time) showed trivial and non-significant associations with running economy. This is important as these outcomes are often relatively easy to measure by wearables and are often key performance indicators to evaluate during technical sprint analysis. Indeed, several wearables claim to estimate running economy based on these outcomes. However, our findings show that this approach is not justified by current evidence.
Among the spatiotemporal outcomes, only a higher step frequency was weakly associated with a better RE. This finding is also in line with the findings of studies showing that most recreational runners often select a step frequency that is below their mathematical optimum. Athletes and coaches may use wearable technology to increase running economy by having athletes adopt a higher step frequency, while maintaining the same running speed. For example, if you are an athlete, you can simply use a wearable watch with a metronome that is set 5 or 10 steps/min higher than your self-selected step frequency to increase your self-selected step frequency. Alternatively, you may run to the beat of music that has a beat frequency set 5 or 10 beats/min higher than your self-selected step frequency to increase your step frequency (10).
Vertical oscillation
Vertical oscillation refers to the upward and downward movement of your body. A higher vertical oscillation was moderately associated with a higher energy cost (poorer running economy) in the review (2). Similarly, a lower leg stiffness was moderately associated with a higher energy cost. This means that athletes who flex more at their hip, knee, or ankle during the stance phase, and who propel vertically higher into the air during the flight phase have a poorer RE. While the biomechanical reasons for this are beyond the scope of this blog, there are some important implications to this finding. However, as an example explanation: a higher vertical oscillation requires more muscle force, which in turn requires the recruitment of more energy costly motor units.
First, adopting a higher step frequency can reduce the vertical oscillation, and this is therefore one approach to improve RE. However, the magnitude of the correlation for stiffness was larger meaning that other factors also contribute. Indeed, we also observed that the magnitude of knee extensor muscle activation was associated with running economy, albeit non-significantly. Specifically, a higher activation of selected knee extensor muscles was associated with a better running economy, probably because a higher activation ensured a higher stiffness of the legs and thus lower vertical oscillation. This higher stiffness in turn improves the use of elastic energy in tendons and reduces the work that muscles need to produce. It may therefore be worthwhile to focus on exercises that increase knee (and hip and ankle) extensor muscle activation and thereby increase vertical/leg stiffness. Exercises that may be useful to this purpose might include plyometric exercises, such as (double legged) bounds (Figure 2) and low hurdle runs (Figure 3), but may also include resistance training exercises, such as isometric strength training, maximal dynamic strength training and Olympic lifting derivatives. Specifically, the plyometric exercises such as ankle bounds and hurdle runs may predominantly increase the ability to active the ankle extensors, whereas the strength-based exercises may contribute more to neural and morphological adaptations in the knee and hip extensors, thus both contributing to increasing lower-limb stiffness.
Full video available from: https://www.youtube.com/watch?v=MLjNBCGGGUE
Footstrike pattern
Popular books and blogs will often tell you that it is more efficient to land on the front of your foot (i.e. fore-foot) as opposed to on your heel. We also investigated whether a so-called ‘front-foot or mid-foot strike’ is indeed more economical than a so-called ‘rearfoot strike’. The results of this analysis are shown in Figure 4. As you can see, the difference in running economy between the two footstrike is only -0.02 units (standard deviations), and it is clearly not significant. Therefore, the current scientific evidence does not support one footstrike type as being more economical than another one!
From a RE perspective, it is therefore probably not a good idea to change your footstrike pattern. Indeed, one study investigated whether changing footstrike pattern improved running economy over 14 weeks of training, but it did not make runners more efficient (11).
Challenges and Considerations
While the relationship between running biomechanics and RE is well-established, it’s important to note that individual differences in anatomy, strength, and flexibility mean that what works for one athlete may not work for another. It’s crucial to tailor training and technique adjustments to the individual. Additionally, while improving RE can significantly enhance performance, it’s just one piece of the puzzle.
Conclusion
By understanding and improving the biomechanics of running, athletes can enhance their RE, leading to better performance with less energy expenditure and fatigue. The practical exercises and strategies outlined in this blog provide a roadmap for athletes and coaches to improve RE, with applications extending beyond endurance sports to any activity requiring speed and efficiency.
Incorporating metronome-guided running, plyometrics, strength training, and technique drills into a training regimen can yield significant improvements in RE. Moreover, monitoring progress through testing, video analysis, and wearable technology ensures that these adjustments lead to tangible performance gains.
As such, we believe that understanding and applying the principles of running economy is essential for athletes at all speeds of movement. By integrating these approaches into your training, you can improve speed, endurance, and movement efficiency in your sport, whether you’re running a marathon, sprinting on the track or on a pitch.
References
1. Dolci F, Kilding A, Spiteri T et al. Characterising running economy and change of direction economy between soccer players of different playing positions, levels and sex. Eur J Sport Sci. 2022;22(8):1167-76.
2. Van Hooren B, Jukic I, Cox M, Frenken K, Bautista IJ, Moore IS. The Relationship Between Running Biomechanics and Running Economy: A Systematic Review and Meta-Analysis of Observational Studies. Sports Med. 2024;54:1269–316.
3. Helgerud J, Rodas G, Kemi OJ, Hoff J. Strength and endurance in elite football players. Int. J. Sports Med. 2011;32(9):677-82.
4. Bangsbo J, Nørregaard L, Thorsø F. Activity profile of competition soccer. Can. J. Sport Sci. 1991;16(2):110-6.
5. Malone S, Solan B, Collins KD, Doran DA. Positional Match Running Performance in Elite Gaelic Football. J Strength Cond Res. 2016;30(8):2292-8.
6. Coutts AJ, Quinn J, Hocking J, Castagna C, Rampinini E. Match running performance in elite Australian Rules Football. J. Sci. Med. Sport. 2010;13(5):543-8.
7. Janetzki SJ, Bourdon PC, Norton KI, Lane JC, Bellenger CR. Evolution of Physical Demands of Australian Football League Matches from 2005 to 2017: A Systematic Review and Meta-Regression. Sports Med Open. 2021;7(1):28.
8. Van Hooren B, Lennartz R, Cox M, Hoitz F, Plasqui G, Meijer K. Differences in running technique between runners with better and poorer running economy and lower and higher milage: An artificial neural network approach. Scand. J. Med. Sci. Sports. 2024;34(3):e14605.
9. Chen S, Segers V, Zhang Q, Zhang Q, Ding H, Li F. Lower extremity kinematic and kinetic characteristics as effects on running economy of recreational runners. Med. Sci. Sports Exerc. 2024.
10. Brake Mt, Stolwijk N, Staal B, Van Hooren B. Using beat frequency in music to adjust running cadence in recreational runners: A randomized multiple baseline design. Eur J Sport Sci. 2022:1-10.
11. Ekizos A, Santuz A, Arampatzis A. Short- and long-term effects of altered point of ground reaction force application on human running energetics. J. Exp. Biol. 2018;221(Pt 15):jeb.176719.
