The possible relationships between foot strike pattern and running performance are controversial topics of discussion (16,18,22,25). Although foot strike pattern can be variable, three patterns are commonly distinguished (8): 1) rearfoot strike, in which the heel contacts the ground first; 2) midfoot strike, in which the heel and ball of the foot contact the ground simultaneously; and 3) forefoot strike, in which the ball of the foot contacts the ground before the heel. It was observed during a half-marathon race (16) that 78%, 20%, and 2% of runners adopted rearfoot, midfoot, and forefoot strike patterns, respectively. Recently, an even higher percentage of rearfoot strikers (approximately 94%, 5%, and 1%, respectively) was observed during a marathon race (19). Furthermore, the percentage of rearfoot strikers increased from 88% to 93% when the same competitors were analyzed at 10 and 32 km of a marathon, respectively (21).
There is controversy about the influence of foot strike pattern on running performance, and recent studies have shown contradictory results (19,21). Some of them observed a lower percentage of rearfoot strikers among elite performers than low performers (16,19), whereas others did not observe this tendency (21). Both midfoot and forefoot patterns may enable a better stretching of the foot arch and a better storage and release of elastic energy from tendons, ligaments, and muscles of the lower limbs during the first part of ground contact (22,25). Forefoot and midfoot strikers also have shorter contact time with the ground (5,13,16,24), increasing leg stiffness and possibly improving running economy (10). To the contrary, three previous studies demonstrated that changing the foot strike pattern (from rearfoot to forefoot and vice versa) did not have any acute effect on running economy (1,7,25). However, these studies were not performed with the natural foot strike pattern of the runners, which may have influenced their results. Further, the biomechanical and physiological implications of a change of the natural foot strike pattern are still unknown (26).
Most of the aforementioned studies did not take into account runners’ physiological characteristics or performance level (5,13,22,24), which could have affected their findings. A recent study has simultaneously compared biomechanical and physiological parameters of runners who naturally used different foot strike patterns (13). It showed no significant differences in running economy between rearfoot and forefoot strikers, although rearfoot pattern tended to be more economical than forefoot one (13). The four studies that analyzed the influence of foot strike pattern on running economy were performed on recreational runners (1,7,13,25) when, paradoxically, forefoot strike pattern seems to be more common among high-level performers (16,19).
The purpose of the present study was to analyze the influence of foot strike pattern (rearfoot vs midfoot) on running economy and biomechanical characteristics (contact and flight times, step rate, and step length) in subelite long-distance runners with similar performance level. The hypothesis was that habitually rearfoot striking runners would have longer contact times and better running economy than midfoot strikers.
Twenty healthy athletes participated in the study. All were well-trained, long-distance runners and competitors with 12± 6 yr of training experience. Their typical training volume during the month preceding the study was 91 ± 24 km·wk−1. Following the criteria of Hasegawa et al. (16), runners were divided into two groups according to their foot strike pattern: rearfoot (n = 10; mean ± SD; age = 26.2 ± 6.5 yr, body mass = 68.1 ± 4.7 kg, height = 1.80 ± 0.06 m) and midfoot/forefoot (n = 10; mean ± SD; age = 28.7 ± 6.6 yr, body mass = 66.1 ± 5.7 kg, height = 1.77 ± 0.04 m). The following inclusion criteria were applied: runners must have competed at least one half-marathon during the 6-wk period before the study; their performance level must be between 1:05:00 and 1:15:00 hh:mm:ss, determined by the “chip time” (time from the start to the finish line after 21,097 m). In fact, the range of performance was very narrow (between 1:06:40 and 1:14:09 hh:mm:ss). Subjects were informed of the procedures, methods, benefits, and possible risks involved in the study before their written consent was obtained. The study was approved by the University Ethics Committee and met the requirements of the Declaration of Helsinki.
All runners were evaluated during their preparatory period (September–December). They reported to the laboratory on two different days, with an interval of at least 1 wk. On the first day, anthropometric characteristics were registered and an incremental treadmill V˙O2max test was performed. On the second day, a submaximal test at different running speeds was performed. All testing sessions were conducted at the same time of day (between 10:00 a.m. and 1:00 p.m.), under similar environmental conditions (∼800 m altitude, 20°C–25°C, 20%–35% relative humidity), and after a 24-h period of no hard training. On these days, a correct intake of carbohydrate and rehydration was recommended (23). Both running tests were preceded by a standardized warm-up (treadmill running at 10–12 km·h−1 for 10 min followed by 5 min of free stretching). All runners wore the same running shoes in every testing session (250–300 g weight for each shoe) to prevent this variable from affecting running economy (12,15).
Running tests were performed on a treadmill (HP Cosmos Pulsar; HP Cosmos Sports & Medical GMBH, Nussdorf-Traunstein, Germany) with 1% of slope in an attempt to mimic the effects of air resistance on the metabolic cost of flat outdoor running (23). Two fans were placed around the treadmill (∼50–100 cm) to cool the subjects during running (one in front and one on the left side) (23). Respiratory gases (Medisoft Ergocard; Medisoft Group, Sorinnes, Belgium) and HR (Polar Team; Polar Electro Oy, Kempele, Finland) were monitored throughout the tests. As suggested in previous studies (24), a contact laser platform (SportJUMP System PRO®, DSD Inc., León, Spain) installed in the treadmill was used to obtain running biomechanical parameters. Specific software (Sport-Bio Running; DSD Inc., León, Spain) allowed the analysis of contact and flight times, step rate, and step length during running. A minimum recording time of 20 s was set at each running speed to obtain at least 32–64 consecutive steps and thus reduce the effect of intraindividual step variability (2). Runners’ foot strike pattern was determined using a high-speed video camera (Casio Exilim Pro EX-F1; Casio Europe GMBH, Norderstedt, Germany) placed on the right side of the treadmill (∼1 m), perpendicular to the sagittal plane at a height of 40 cm. All runners were analyzed by the same observer, who identified their foot strike pattern at 18 km·h−1. This running speed was chosen as representative of intense training (23) and coincided with the runners’ pace in the half-marathon (∼3 min 20 s·km−1). Because of the low percentage of midfoot and forefoot strikers during long-distance races, most studies classify them in the same category (16,21). Therefore, in this study, runners who appeared to land on the ball of the foot first (i.e., forefoot) or who landed with the heel and ball of the foot simultaneously (i.e., midfoot) were grouped together as midfoot strikers (5).
Before the incremental test, each subject’s body mass and height were recorded, together with six skinfold measurements (triceps, subscapular, suprailiac, abdominal, front thigh, and medial calf) using standard equipment (HSB-BI; British Indicators LTD, West Sussex, UK). The total leg and lower leg (shank) lengths were obtained (Harpender anthropometer; CMS Instruments, London, UK). Maximal thigh and shank (i.e., calf) circumferences as well as minimum ankle circumference were measured (Holtain LTD; Crymych, UK). All measurements were made by the same researcher following the criteria of previous studies (23).
The test started at 6 km·h−1, and treadmill speed was increased 1 km·h−1 every 1 min until volitional exhaustion. V˙O2max and HRmax were recorded as the highest values obtained in the 30 s before exhaustion (11). The ventilatory threshold and the respiratory compensation threshold were identified according to the criteria of Davis (9). Biomechanical parameters were only analyzed between 10 and 20 km·h−1 to ensure that all subjects were running (i.e., with flight time) and reached at least that top speed. Biomechanical parameters were registered in the last 20 s of each running speed.
Subjects performed 6 min of running at 11, 13, and 15 km·h−1 with a 5-min rest in between. V˙O2 and HR were continuously registered during the test, considering the average of the last 3-min period of each set as representative data (23). Running economy was determined as the V˙O2 cost at a given running speed (i.e., mL·kg−1·min−1 and mL·kg−1·km−1 ). Biomechanical parameters were registered for a minimum of 20 s during the fifth minute of each set.
The results are expressed as mean ± SD. The Kolmogorov–Smirnov test was applied to ensure a Gaussian distribution of all results. A one-way ANOVA was used to analyze the differences between both groups of runners. Repeated-measures ANOVA was used to analyze the effect of running speed on biomechanical parameters. When a significant F value was found, the Newman–Keuls post hoc analysis was used to establish statistical differences between means. SPSS+ version 17.0 statistical software (SPSS, Inc., Chicago, IL) was used. Values of P < 0.05 were considered statistically significant.
No significant differences were detected between rearfoot versus midfoot strikers in performance level (1:10:59 ± 0:02:15 and 1:10:21 ± 0:01:42 hh:mm:ss, respectively), age (26.2 ± 6.5 vs 28.7 ± 6.6 yr, respectively), previous running experience (12.2 ± 7.0 vs 12.0 ± 5.3 yr, respectively), or weekly training volume (92.1 ± 32.6 vs 90.1 ± 13.3 km, respectively). No significant differences in anthropometric variables were observed (Table 1).
Table 2 shows the physiological variables obtained during the incremental and the submaximal tests. No significant differences between rearfoot versus midfoot strikers were observed during the incremental test. However, in the submaximal test, rearfoot strikers demonstrated 5.4% and 9.3% lower V˙O2 and better running economy at 11 and 13 km·h−1, respectively. At 15 km·h−1, the difference was not significant.
Figure 1 shows contact and flight times obtained during the submaximal and the incremental tests. Rearfoot strikers showed longer contact time (P < 0.01) and shorter flight time (P < 0.01) compared with midfoot strikers. Nevertheless, there were no differences in step rate and step length between the two groups of runners at any speed.
Overall, for both groups of runners together, flight time increased (P < 0.001) during the incremental test (n = 20), and contact time decreased (P < 0.001) as running speed increased. Figure 2 shows the effect of running speed on step rate (P < 0.001) and step length (P < 0.001). Step rate increased at 0.123 Hz·m−1·s−1, whereas step length did so at 0.284 m·m−1·s−1.
The main outcome of the present study was that subelite rearfoot striking, long-distance runners had better running economy at submaximal running speeds (between 57% and 81% of V˙O2max) than midfoot strikers (Table 2). Likewise, rearfoot strikers showed longer contact time (P < 0.05) and shorter flight time (P < 0.05) at all running speeds (Fig. 1). Both groups of runners presented the same performance level in a half-marathon, which allowed us to separate the effect of the foot strike pattern on running economy and biomechanics. This is the first study that simultaneously compared physiological and biomechanical characteristics of high-level runners who naturally used rearfoot versus midfoot strike patterns.
Previous studies observed that in long-distance races, a smaller percentage of the faster runners used a rearfoot strike pattern, suggesting that midfoot strike pattern is associated with a high performance level (16,19). However, another study did not detect this (21). In the present study, the two groups of high-level runners (rearfoot and midfoot strikers) showed no differences in performance, anthropometric (Table 1), or physiological (Table 2) variables other than running economy. In one of the most recent studies on this topic, Kasmer et al. (2013) made a claim for the possible causes of the discrepancy with respect to the results of Larson et al. (2011): different performance level, different sample size, different foot strike classification, and other technological considerations (type of camera, camera location, etc.). The results of the present study supported Larson et al. (2011) and showed no influence of the foot strike pattern on performance or on other associated factors such as physiological variables.
In the present study, rearfoot strikers had lower V˙O2 and better running economy than midfoot strikers at 11 and 13 km·h−1 (Table 2). These results are not in line with previous studies that changed (1,7,25) or maintained (13) the natural foot strike pattern of the runners at similar submaximal running speeds (between 9 and 15 km·h−1). These studies did not observe any difference in running economy between both foot strike patterns, although a recent study showed a tendency of rearfoot pattern to be more economical than forefoot one (13). In the present study, two groups of 10 subelite male runners participated, whereas Gruber et al. (2013) used two groups of gender mixed runners with unknown performance level and unidentified physiological characteristics. Thus, both studies concur that midfoot strikers were not more economical than rearfoot ones, although more scientific evidence is necessary to confirm the better running economy of rearfoot strikers. The observed differences in running economy between rearfoot and midfoot strikers of the present study (5.4%, 9.3%, and 5.0% at 11, 13 and 15 km·h−1, respectively) were comparable with the differences (6%–7%) observed between elite male and female long-distance runners (6) and between African and Caucasian runners (28). Taking into account the results of the present study (Table 2), rearfoot strikers could run ∼1 km·h−1 faster than midfoot strikers with the same energy expenditure (between 11 and 15 km·h−1). Running economy at 15 km·h−1 was not significantly different (P = 0.07) between the two groups of runners, possibly because of a higher dispersion of both V˙O2 and running economy values in the rearfoot strikers. In this study, at 13 and 15 km·h−1, both groups of runners obtained between 60% and 90% of their V˙O2max, where running economy was steady.
The advocates of “barefoot running” or “minimalist running” speculate about the possible advantages of midfoot strike patterns on running performance (22,25). Theoretically, this type of foot strike pattern allows a better stretching of the arch of the foot and better elastic energy storage of tendons, ligaments, and muscles of the lower limbs during the first part of ground contact. However, to our knowledge, there is no scientific evidence of this advantage for running economy or even for running performance (25). The aforementioned advantages might only appear at very high running speeds, and not in submaximal running. Recent studies (18) observed that the prevalence of rearfoot and midfoot/forefoot strikers (31% and 69%, respectively) was reversed in middle-distance races (800–1500 m) compared with long-distance races (93%–94% and 6%–7%, respectively) (19,21). Training and competitive running speeds chosen by middle-distance runners (∼20–25 km·h−1) and long-distance runners (∼15–20 km·h−1) could justify this inversion of foot strike pattern prevalence. According to the results of this study, midfoot strikers did not show better running economy at submaximal running speeds (≤15 km·h−1), which are normally chosen by recreational runners.
The foot strike pattern did not influence step rate and step length at the same running speed. However, rearfoot strikers showed longer contact time (between 7% and 13%) and shorter flight time (between 13% and 35%) compared with midfoot strikers (Fig. 1). These contact time differences (∼10%) were in line with previous studies when comparing rearfoot versus midfoot strikers (5,13,16,18,24) and could explain the observed differences in running economy (between 5.0% and 9.3%). Roberts et al. (27) found that most (70%–90%) of the metabolic cost in running bipeds was due to the time available to generate force. Therefore, an inverse relationship between the metabolic cost of running and the time the foot applied force to the ground was described (20). The mechanism by which rearfoot strikers needed longer contact time was previously explained (18). These runners contacted the floor with a more extended leg and needed more time to reach the maximum knee flexion during the braking phase (18). On the other hand, in the present study, the midfoot strikers showed longer flight times and possibly a greater oscillation of the center of mass, which has been associated with poor running economy (14). Because this study only analyzed flight time and not the oscillation of the center of mass, future studies should examine this issue. In addition, because of the observed differences between rearfoot and midfoot strikers in contact and flight times, future studies should take into account runners’ foot strike pattern when associating contact time and running economy.
In the present study, taking both groups of runners together (n = 20), the decrease of contact time with the increase of running speeds was ∼10 ms every 1 km·h−1 (Fig. 1), comparable with the ∼20 ms every 2 km·h−1 found in a previous study (24). Moreover, the increase of running speed (from 10 to 20 km·h−1) was due more to an increase of step length (from 1.01 to 1.79 m, 77%) than to an increase of step rate (from 2.75 to 3.10 Hz, 13%) (Fig. 2). It was well known that the increase in speed during submaximal efforts (i.e., endurance running) is due to an increase of step length, while during supramaximal efforts (i.e., sprint running), it is due to an increase of step rate (3,17). In this study, the increases found in step length and step rate (0.123 Hz·m−1·s−1 and 0.284 m·m−1·s−1, respectively) were similar to those shown in previous studies (0.115 Hz·m−1·s−1 and 0.299 m·m−1·s−1, respectively) with runners of similar anthropometric characteristics (179.3 cm) (4). Qualitatively, they were also similar to the quadratic relationships described in previous studies (17): concave upward between step rate and running speed, and concave downward between step length and running speed.
One of the limitations of this study was that runners’ foot strike pattern was determined at 18 km·h−1 (representative of the runners’ pace during the half-marathon), whereas running economy was tested at slower speeds (11–15 km·h−1). We assumed that foot strike pattern did not change during submaximal speeds, but future studies should verify this. Furthermore, the submaximal test could have been performed at 13, 15, and 17 km·h−1 instead of 11, 13, and 15 km·h−1. Energy expenditure at 11 km·h−1 did not reach the 60% of V˙O2max, whereas it was 78% and 81% of V˙O2max at 15 km·h−1 for rearfoot and midfoot strikers, respectively. Nevertheless, for some runners, the energy expenditure at 17 km·h−1 could be higher than 90% of V˙O2max, where running economy should not be assessed because of the contribution of anaerobic metabolism (1).
In conclusion, the results of the present study showed that rearfoot strikers were more economical than midfoot strikers at submaximal running speeds (57%–81% of V˙O2max). Biomechanically, the foot strike pattern did not influence either step rate or step length at the same running speed but affected both contact (longer in rearfoot runners) and flight time (longer in midfoot runners). The observed differences in these biomechanical parameters could explain the differences in running economy.
The authors thank the runners who participated in this study for their collaboration. The study was supported by the University of León and the Spanish Sports Council (CSD) (157/UPB10/12), Spain. They also thank the Basque Government for supporting Ana Ogueta-Alday with a predoctoral grant (2011–2014). The authors have no conflicts of interest to disclose.
The authors, Ana Ogueta-Alday, José Antonio Rodríguez-Marroyo, and Juan García-López, have no conflict of interest.
The results of the present study do not constitute endorsement by the American College of Sports Medicine.
1. Ardigò LP, Lafortuna C, Minetti AE, Mognoni P, Saibene F. Metabolic and mechanical aspects of foot landing type, forefoot and rearfoot strike, in human running. Acta Physiol Scand
. 1995; 155 (1): 17–22.
2. Belli A, Lacour JR, Komi PV, Candau R, Denis C. Mechanical step variability during treadmill running. Eur J Appl Physiol Occup Physiol
. 1995; 70 (6): 510–7.
3. Bramble DM, Lieberman DE. Endurance running and the evolution of Homo. Nature
. 2004; 432 (7015): 345–52.
4. Cavanagh PR, Kram R. Stride length in distance running: velocity, body dimensions, and added mass effect. Med Sci Sports Exerc
. 1989; 21 (4): 467–79.
5. Cavanagh PR, Lafortune MA. Ground reaction forces in distance running. J Biomech
. 1980; 13 (5): 397–406.
6. Chapman RF, Laymon AS, Wilhite DP, McKenzie JM, Tanner DA, Stager JM. Ground contact time as an indicator of metabolic cost in elite distance runners. Med Sci Sports Exerc
. 2012; 44 (5): 917–25.
7. Cunningham CB, Schilling N, Anders C, Carrier DR. The influence of foot posture on the cost of transport in humans. J Exp Biol
. 2010; 213 (5): 790–7.
8. Daoud AI, Geissler GJ, Wang F, Saretsky J, Daoud YA, Lieberman DE. Foot strike and injury rates in endurance runners: a retrospective study. Med Sci Sports Exerc
. 2012; 44 (7): 1325–34.
9. Davis JA. Anaerobic threshold: a review of the concept and directions for future research. Med Sci Sports Exerc
. 1985; 17 (1): 6–21.
10. 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
. 2010; 5 (2): 249–61.
11. Fletcher JR, Esau SP, Macintosh BR. Economy of running: beyond the measurement of oxygen uptake. J Appl Physiol
. 2009; 107 (6): 1918–22.
12. Franz JR, Wierzbinski CM, Kram R. Metabolic cost of running barefoot versus shod: is lighter better? Med Sci Sports Exerc
. 2012; 44 (8): 1519–25.
13. Gruber AH, Umberger BR, Braun B, Hamill J. Economy and rate of carbohydrate oxidation during running with rearfoot or forefoot strike patterns. J Appl Physiol
. 2013; 115 (2): 194–201.
14. Halvorsen K, Eriksson M, Gullstrand L. Acute effects of reducing vertical displacement and step frequency on running economy. J Strength Cond Res
. 2012; 26 (8): 2065–70.
15. Hanson NJ, Berg K, Deka P, Meendering JR, Ryan C. Oxygen cost of running barefoot vs. running shod. Int J Sports Med
. 2011; 32 (6): 401–6.
16. Hasegawa H, Yamauchi T, Kramer WJ. Foot strike patterns of runners at the 15 km point during an elite-level half marathon. J Strength Cond Res
. 2007; 21 (3): 888–93.
17. Hay JG. Cycle rate, length, and speed of progression in human locomotion. J Appl Biomech
. 2002; 18 (3): 257–70.
18. Hayes P, Caplan N. Foot strike patterns and ground contact times during high-calibre middle-distance races. J Sports Sci
. 2012; 30 (12): 1275–83.
19. Kasmer ME, Liu XC, Roberts KG, Valadao JM. Foot-strike pattern and performance in a marathon. Int J Sports Physiol Perfom
. 2013; 8 (3): 286–92.
20. Kram R, Taylor CR. Energetics of running: a new perspective. Nature
. 1990; 346 (6281): 265–7.
21. Larson P, Higgins E, Kaminski J, et al. Foot strike patterns of recreational and sub-elite runners in a long-distance road race. J Sports Sci
. 2011; 29 (15): 1665–73.
22. Lieberman DE, Venkadesan M, Werbel WA, et al. Foot strike patterns and collision forces in habitually barefoot versus shod runners. Nature
. 2010; 463 (7280): 531–5.
23. Lucia A, Esteve-Lanao J, Oliván J, et al. Physiological characteristics of the best Eritrean runners-exceptional running economy. Appl Physiol Nutr Metab
. 2006; 31 (5): 530–40.
24. Ogueta-Alday A, Morante JC, Rodríguez-Marroyo JA, García-López J. Validation of a new method to measure contact and flight times during treadmill running. J Strength Cond Res
. 2013; 27 (5): 1455–62.
25. Perl DP, Daoud AI, Lieberman DE. Effects of footwear and strike type on running economy. Med Sci Sports Exerc
. 2012; 44 (7): 1335–43.
26. Rixe JA, Gallo RA, Silvis ML. The barefoot debate: can minimalist shoes reduce running-related injuries. Curr Sports Med Rep
. 2012; 11 (3): 160–5.
27. Roberts TJ, Kram R, Weyand PG, Taylor CR. Energetics of bipedal running. I. Metabolic cost of generating force. J Exp Biol
. 1998; 201 (Pt 19): 2745–51.
28. Weston AR, Mbambo Z, Myburgh KH. Running economy of African and Caucasian distance runners. Med Sci Sports Exerc
. 2000; 32 (6): 1130–4.