In this study, we compared specific anthropometric, neuromuscular, and biomechanical lower-body measures and explored relationships between measures in a large sample of well-trained male and female distance runners in an attempt to identify key determinants of running economy. Athletes such as distance runners rely on efficient utilization of available energy to facilitate optimum performance. The results of this investigation suggest that differences in running economy between distance runners seem in part to be the result of select modifiable and nonmodifiable lower-body characteristics, which may also explain differences in performance.
It is well known that stiffer muscles, or tendons, are more economical at transferring energy (10,16,34,53). The stiffness values in our 63 well-trained runners (male, 9.4 kN·m−1; female, 13.3 kN·m−1) were similar to those of Dumke et al. (20) (11.8 kN·m−1) and Fukashiro et al. (22) (9.6 kN·m−1) using well-trained and untrained men and women, respectively. Similar to other studies (2,20), the present data demonstrated that lower-body stiffness is substantially related to running economy of well-trained runners (Table 3; Figure 3). Although it remains to be determined the trainability of stiffness across varying levels of fitness, emerging evidence suggests that runners and coaches may want to focus on strategies to improve lower-body stiffness to enhance performance. Indeed, previous evidence has also shown that running economy is strongly related to performance times at distances >800 m (15,39). This study also showed that lower-body stiffness was related to the moment arm of the Achilles tendon (Figure 3). This is a unique finding not previously reported in the literature and suggests that the Achilles moment arm may affect stiffness properties after training. The relationship between resistance training and plyometric training and running economy is not a new concept. In fact, several research investigations have shown that strength training (both high resistance and explosive) can improve running economy by modulating lower-body stiffness (3,46,53).
The results of previous studies have identified a number of biomechanical variables that relate to running economy, including stride length that is freely chosen (11,13,14,38,42,54), low vertical oscillation of body center of mass (13,54), and low peak ground reaction forces (54,55). In this study, we considered the basic biomechanical characteristics most often reported in the literature. Stride length was moderately correlated with running economy in this study. Relationships between running economy and stride length, expressed as an absolute or relative to height or leg length, have also been low to moderate (13,14,54). The most striking and ubiquitous finding regarding stride length and running is that a freely chosen stride length is most economical (12,24,38,42,55). Experimentally induced deviations from this freely chosen stride length have invariably evoked increased oxygen cost (14,24). There is a natural reciprocal relationship between stride length and stride rate, suggesting that runners naturally acquire an optimal stride rate based on perceived exertion (14). It is not surprising then that stride rate was also small-moderately correlated with running economy. The balance between the time during which the foot is in contact with the ground (contact time) and not in contact with the ground (flight time) has been studied in relation to running economy, but with no consistent findings. Likewise, we found small correlation between contact time and running economy in men and a large correlation in women; furthermore, there was no correlation between flight time and running economy in men, but very large correlation in women. Previous studies have found that longer contact times and shorter flight times were associated with poorer economy (54), which our female results support, whereas others have found the opposite relationship (43), and others no relationship (13,55), which our male results support. There is an intuitive link between running mechanics and energy cost of running, but research to date has not established a clear mechanical profile of an economical runner. The results of this study corroborate this statement. It seems that through training, individuals are able to integrate and accommodate their own unique combination of dimensions and mechanical characteristics so that they arrive at a running motion that is most economical for them.
In summary, despite some substantial correlations between some lower-body measures and running economy, it seems that no single lower-body measure can completely explain differences in running economy within and between genders. Other factors such as body lengths, mass distribution, fiber type, vertical oscillation, footstrike patterns, and other kinetic and kinematics are also likely to affect running economy. Running economy is therefore likely determined from the sum of influences from multiple lower-body attributes.
Many of the lower-body characteristics measured in this study represent specific or independent qualities of running economy that can be assessed and trained independently. Given the strong relationship between running economy and stiffness as indicated by our results, perhaps a greater efficiency of training can be achieved by targeting interventions that increase leg stiffness to improve running economy. The Achilles moment arm length is a nonmodifiable determinant related to running economy and seems to provide the practitioner with information about the stiffness of the lower body, which may elucidate an athlete's potential to improve their running economy, however more data are needed to validate this. The data we have presented here for a variety of lower-body measures commonly measured in athletes give an indication of normative ranges for well-trained male and female runners.
The authors would like to thank the subjects for their participation. The authors have no professional relationship with a for-profit organization that would benefit from this study and no financial assistance with the project was received.
1. Anderson T. Biomechanics
and running economy
. Sports Med 22: 76–89, 1996.
2. Arampatzis A, De Monte G, Karamanidis K, Morey-Klapsing G, Stafilidis S, Bruggemann GP. Influence of the muscle-tendon unit's mechanical and morphological properties on running economy
. J Exp Biol 209: 3345–3357, 2006.
3. Barnes KR, Hopkins WG, McGuigan MR, Northuis ME, Kilding AE. Effects of resistance training on running economy
and cross-country performance. Med Sci Sports Exerc 2013. In press.
4. Bhambani Y, Singh M. Metabolic and cinematographic analysis of walking and running
in men and women. Med Sci Sports Exerc 17: 131–137, 1985.
5. Bonacci J, Chapman A, Blanch P, Vicenzino B. Neuromuscular adaptations to training, injury and passive interventions: Implications for running economy
. Sports Med 39: 903–921, 2009.
6. Bransford DR, Howley ET. Oxygen cost of running
in trained and untrained men and women. Med Sci Sports 9: 41–44, 1977.
7. Brooks GA, Fahey TD, White TP. Exercise Physiology: Human Bioenergetics and its Applications. Mountain View, CA: Mayfield Pub. Co., 1996.
8. Bunc V, Heller J. Energy cost of running
in similarly trained men and women. Eur J Appl Physiol Occuo Physiol 59: 178–183, 1989.
9. Cavagna GA, Franzetti P, Heglund NC, Willems P. The determinants of the step frequency in running
, trotting and hopping in man and other vertebrates. J Physiol 399: 81–92, 1988.
10. Cavagna GA, Kaneko M. Mechanical work and efficiency in level walking and running
. J Physiol 268: 467–481, 1977.
11. Cavagna GA, Willems PA, Franzetti P, Detrembleur C. The two power limits conditioning step frequency in human running
. J Physiol 437: 95–108, 1991.
12. Cavanagh PR, Kram R. The efficiency of human movement—A statement of the problem. Med Sci Sports Exerc 17: 304–308, 1985.
13. Cavanagh PR, Pollock ML, Landa J. A biomechanical comparison of elite and good distance runners. Ann N Y Acad Sci 301: 328–345, 1977.
14. Cavanagh PR, Williams KR. The effect of stride length variation on oxygen uptake during distance running
. Med Sci Sports Exerc 14: 30–35, 1982.
15. Conley DL, Krahenbuhl GS. Running economy
and distance running
performance of highly trained athletes. Med Sci Sports Exerc 12: 357–360, 1980.
16. Dalleau G, Belli A, Bourdin M, Lacour JR. The spring-mass model and the energy cost of treadmill running
. Eur J Appl Physiol Occuo Physiol 77: 257–263, 1998.
17. Daniels JT, Daniels N. Running economy
of elite male and elite female runners. Med Sci Sports Exerc 24: 483–489, 1992.
18. Daniels JT, Krahenbuhl G, Foster C, Gilbert J, Daniels S. Aerobic responses of female distance runners to submaximal and maximal exercise. Ann N Y Acad Sci 301: 726–733, 1977.
19. Davies CT, Thompson MW. Aerobic performance of female marathon and male ultramarathon athletes. Eur J Appl Physiol Occuo Physiol 41: 233–245, 1979.
20. Dumke CL, Pfaffenroth CM, McBride JM, McCauley GO. Relationship between muscle strength, power and stiffness
and running economy
in trained male runners. Int J Sports Physiol Perform 5: 249–261, 2010.
21. Franklin DW, Burdet E, Osu R, Kawato M, Milner TE. Functional significance of stiffness
in adaptation of multijoint arm movements to stable and unstable dynamics. Exp Brain Res 151: 145–157, 2003.
22. Fukashiro S, Noda M, Shibayama A. In vivo determination of muscle viscoelasticity in the human leg. Acta Physiol Scand 172: 241–248, 2001.
23. Hoff J, Helgerud J, Wisloff U. Maximal strength training improves work economy in trained female cross-country skiers. Med Sci Sports Exerc 31: 870–877, 1999.
24. Hogberg P. How do stride length and stride frequency influence the energy-output during running
? Arbeitsphysiologie 14: 437–441, 1952.
25. Holloszy JO, Rennie MJ, Hickson RC, Conlee RK, Hagberg JM. Physiological consequences of the biochemical adaptations to endurance exercise. Ann N Y Acad Sci 301: 440–450, 1977.
26. Hopkins P, Powers SK. Oxygen uptake during submaximal running
in highly trained men and women. Am Correct Ther J 36: 130–132, 1982.
27. Hopkins WG. A spreadsheet for deriving a confidence interval, mechanistic inference and clinical inference from a p value. Sportscience 11: 16–20, 2007.
28. Hopkins WG. A spreadsheet to compare means of two groups. Sportscience 11: 22–23, 2007.
29. Hopkins WG, Marshall SW, Batterham AM, Hanin J. Progressive statistics for studies in sports medicine and exercise science. Med Sci Sports Exerc 41: 3–13, 2009.
30. Howley ET, Glover ME. The caloric costs of running
and walking one mile for men and women. Med Sci Sports 6: 235–237, 1974.
31. Johnston R, Quinn T, Kertzer R, Vroman N. Strength training in female distance runners: Impact on running economy
. J Strength Cond Res 11: 224–229, 1997.
32. Jung AP. The impact of resistance training on distance running
performance. Sports Med 33: 539–552, 2003.
33. Kyrolainen H, Belli A, Komi PV. Biomechanical factors affecting running economy
. Med Sci Sports Exerc 33: 1330–1337, 2001.
34. Lichtwark GA, Wilson AM. Optimal muscle fascicle length and tendon stiffness
for maximising gastrocnemius efficiency during human walking and running
. J Theor Biol 252: 662–673, 2008.
35. Maughan RJ, Leiper JB. Aerobic capacity and fractional utilisation of aerobic capacity in elite and non-elite male and female marathon runners. Eur J Appl Physiol Occup Physiol 52: 80–87, 1983.
36. Mayhew JL, Piper FC, Etheridge GL. Oxygen cost and energy requirement of running
in trained and untrained males and females. J Sports Med Phys Fitness 19: 39–44, 1979.
37. McGuigan MR, Doyle TL, Newton M, Edwards DJ, Nimphius S, Newton RU. Eccentric utilization ratio: Effect of sport and phase of training. J Strength Cond Res 20: 992–995, 2006.
38. Morgan DW, Baldini FD, Martin PE, Kohrt WM. Ten kilometer performance and predicted velocity at VO2max among well-trained male runners. Med Sci Sports Exerc 21: 78–83, 1989.
39. Morgan DW, Bransford DR, Costill DL, Daniels JT, Howley ET, Krahenbuhl GS. Variation in the aerobic demand of running
among trained and untrained subjects. Med Sci Sports Exerc 27: 404–409, 1995.
40. Morgan DW, Craib M. Physiological aspects of running economy
. Med Sci Sports Exerc 24: 456–461, 1992.
41. Morgan DW, Martin PE. Effects of stride length alteration on racewalking economy. Can J Appl Sport Sci 11: 211–217, 1986.
42. Morgan D, Martin P, Craib M, Caruso C, Clifton R, Hopewell R. Effect of step length optimization on the aerobic demand of running
. J Appl Physiol (1985) 77: 245–251, 1994.
43. Nummela A, Keranen T, Mikkelsson LO. Factors related to top running
speed and economy. Int J Sports Med 28: 655–661, 2007.
44. Nummela AT, Heath KA, Paavolainen LM, Lambert MI, St Clair Gibson A, Rusko HK, Noakes TD. Fatigue during a 5-km running
time trial. Int J Sports Med 29: 738–745, 2008.
45. Osteras H, Helgerud J, Hoff J. Maximal strength-training effects on force-velocity and force-power relationships explain increases in aerobic performance in humans. Eur J Appl Physiol 88: 255–263, 2002.
46. Paavolainen L, Häkkinen K, Hamalainen I, Nummela A, Rusko H. Explosive-strength training improves 5-km running
time by improving running economy
and muscle power. J Appl Physiol (1985) 86: 1527–1533, 1999.
47. Paavolainen L, Nummela A, Rusko H, Häkkinen K. Neuromuscular characteristics
and fatigue during 10 km running
. Int J Sports Med 20: 516–521, 1999.
48. Paavolainen LM, Nummela AT, Rusko HK. Neuromuscular characteristics
and muscle power as determinants of 5-km running
performance. Med Sci Sports Exerc 31: 124–130, 1999.
49. Pate RR, Macera CA, Bailey SP, Bartoli WP, Powell KE. Physiological, anthropometric, and training correlates of running economy
. Med Sci Sports Exerc 24: 1128–1133, 1992.
50. Raichlen DA, Armstrong H, Lieberman DE. Calcaneus length determines running economy
: Implications for endurance running
performance in modern humans and Neandertals. J Hum Evol 60: 299–308, 2011.
51. Saunders PU, Pyne DB, Telford RD, Hawley JA. Factors affecting running economy
in trained distance runners. Sports Med 34: 465–485, 2004.
52. Scholz MN, Bobbert MF, van Soest AJ, Clark JR, van Heerden J. Running biomechanics
: Shorter heels, better economy. J Exp Biol 211: 3266–3271, 2008.
53. Spurrs RW, Murphy AJ, Watsford ML. The effect of plyometric training on distance running
performance. Eur J Appl Physiol 89: 1–7, 2003.
54. Williams KR, Cavanagh PR. Relationship between distance running
mechanics, running economy
, and performance. J Appl Physiol (1985) 63: 1236–1245, 1987.
55. Williams KR, Cavanagh PR, Ziff JL. Biomechanical studies of elite female distance runners. Int J Sports Med 8(Suppl 2): 107–118, 1987.