This article was downloaded by: [89.7.0.170]On: 29 October 2014, At: 04:42Publisher: RoutledgeInforma Ltd Registered in England and Wales Registered Number: 1072954 Registered office: Mortimer House,37-41 Mortimer Street, London W1T 3JH, UK

Journal of Sports SciencesPublication details, including instructions for authors and subscription information:http://www.tandfonline.com/loi/rjsp20

Comment on Dissociation between running economyand running performance in elite Kenyan distancerunnersJordan Santos-Concejeroa & Ross Tuckeraa UCT/MRC Research Unit for Exercise Science and Sports Medicine, Human Biology,University of Cape Town, Cape Town 7700, South AfricaPublished online: 29 Oct 2014.

To cite this article: Jordan Santos-Concejero & Ross Tucker (2014): Comment on Dissociation between running economy andrunning performance in elite Kenyan distance runners, Journal of Sports Sciences, DOI: 10.1080/02640414.2014.971048

To link to this article: http://dx.doi.org/10.1080/02640414.2014.971048

PLEASE SCROLL DOWN FOR ARTICLE

Taylor & Francis makes every effort to ensure the accuracy of all the information (the Content) containedin the publications on our platform. However, Taylor & Francis, our agents, and our licensors make norepresentations or warranties whatsoever as to the accuracy, completeness, or suitability for any purpose of theContent. Any opinions and views expressed in this publication are the opinions and views of the authors, andare not the views of or endorsed by Taylor & Francis. The accuracy of the Content should not be relied upon andshould be independently verified with primary sources of information. Taylor and Francis shall not be liable forany losses, actions, claims, proceedings, demands, costs, expenses, damages, and other liabilities whatsoeveror howsoever caused arising directly or indirectly in connection with, in relation to or arising out of the use ofthe Content.

This article may be used for research, teaching, and private study purposes. Any substantial or systematicreproduction, redistribution, reselling, loan, sub-licensing, systematic supply, or distribution in anyform to anyone is expressly forbidden. Terms & Conditions of access and use can be found at http://www.tandfonline.com/page/terms-and-conditions

LETTER TO THE EDITOR

Comment on Dissociation between running economy and runningperformance in elite Kenyan distance runners

JORDAN SANTOS-CONCEJERO & ROSS TUCKER

UCT/MRC Research Unit for Exercise Science and Sports Medicine, Human Biology, University of Cape Town, Cape Town7700, South Africa

(Accepted 26 September 2014)

AbstractMooses and colleagues suggest that running economy alone does not explain superior distance running performance in eliteKenyan runners. Whilst we agree with the multi-factorial hypothesis for Kenyan running success, we do not believe thatrunning economy can be overlooked to the extent that it was based on this particular study. Based on the methods used andthe range of athletes tested, in this response letter we question whether this study provides any basis for downplaying theinuence of running economy or suggesting that other factors compensate for it to enable superior performance.

Keywords: metabolic cost, African runners, association, anthropometry, middle-distance runners

Mooses and colleagues recently argued that sincethey found no association between running economy(RE) and running performance in elite Kenyan dis-tance runners, a superior RE per se could notaccount for the superior performance of the EastAfrican runners, and that RE is compensated for byother factors to enable superior distance runningperformance (Mooses et al., 2014).Whilst we agree with the multi-factorial hypothesis

for Kenyan running success, as acknowledged byMooses et al. (2014) and argued elsewhere (Larsen,2003; Tucker, Santos-Concejero, & Collins, 2013;Wilber & Pitsiladis, 2012), we do not believe thatRE can be overlooked or even downplayed to theextent that it was based on this particular study.Previous research in African runners in general(Weston, Mbambo, & Myburgh, 2000), and EastAfrican runners in particular (Lucia et al., 2006;Saltin et al., 1995) has shown that African runnersare more metabolically economical than eliteEuropean runners. Even studies that did not ndRE differences between elite Kenyan and Europeanrunners reported that RE, together with VO2max andthe fraction of the VO2max that can be sustained over

a race distance, are strong predictors of performance(Tam et al., 2012).The absence of such an association in the study of

Mooses et al. (2014) may be the result of a number ofmethod related issues which must be acknowledgedbefore any conclusions regarding RE can be made.First, Mooses et al. (2014) apply a questionable stan-dard to the denition of homogenous when deningtheir elite athlete sample, with respect to both abilityand the events they excel in. They analysed the bestperformances of 32 elite Kenyan runners, competingin distances ranging from 800m to themarathon. Evenif we accept, for example, that runners with 800 mpersonal best performances ranging from 1:47 to 1:53are homogenous, it seems conicting to group togetherand analyse athletes from distances as different as800 m and the marathon. Further, we would alsoquestion the characterisation of the athletes tested byMooses et al. (2014) as elite. The athletes are cer-tainly competitive and superior to almost all thosestudied in previous research, but may fall slightlybelow the elite level (La Torre, Vernillo, Agnello,Berardelli, & Rampinini, 2011). We do not howeverconsider this difference to affect the veracity of the

Correspondence: Jordan Santos-Concejero, UCT/MRC Research Unit for Exercise Science and Sports Medicine, Human Biology, University of Cape Town,3 Floor Sports Sciences Institute of South Africa, Boundary Road, Newlands, Cape Town 7700, South Africa. E-mail: jordan.santosconcejero@uct.ac.za

Journal of Sports Sciences, 2014http://dx.doi.org/10.1080/02640414.2014.971048

2014 Taylor & Francis

Dow

nloa

ded

by [8

9.7.0.

170]

at 04

:42 29

Octo

ber 2

014

conclusionsmade byMooses et al. (2014), and suggestthat the lack of homogeneity is the key factor under-mining their conclusions. This is not a trivial matter,for the contribution of RE to performance is differentfor an 800-m athlete and a marathon runner, as is themethod by which RE would be used to predict perfor-mance (Saunders, Pyne, Telford, & Hawley, 2004).First, it is widely known that the metabolic cost

and pulmonary VO2 kinetics differ between middle-and long-distance runners (Chapman et al., 2012;Kilding, Fysh, & Winter, 2007). Second, it is knownthat the speeds at which runners are tested inu-ences laboratory measures of RE, as middle-distancerunners are more economical at faster speeds andlong-distance runners at slower speeds (Daniels &Daniels, 1992). Since Mooses et al. (2014) tested allrunners at a speed of 16 km h1, we would questionwhether this satises the relative-speed range of run-ners in the sample group, and would suggest that itexplains why this apparently homogenous group hada range of VO2 from 55 to 67 ml kg

1 min1 atthat particular speed.In events such as in 800 m, the accumulated oxy-

gen decit alone can actually predict up to 89% ofrunning performance (Nevill, Ramsbottom, Nevill,Newport, & Williams, 2008). Similarly, whereas forthe 800m, aerobic pathways contribute approxi-mately 60% of total energy (Dufeld, Dawson, &Goodman, 2005), the marathon is almost exclusivelyaerobic (~100%) and its performance can be almostentirely predicted by the following equation (Tamet al., 2012):

VO2max VO2maxfraction that can be sustainedduring the marathon RE1

RE and VO2max can also explain up to 95% of thevariance in middle-distance running performance,but since the predicting model for middle-distancerunning is different a proportional curvilinear ratioof VO2max divided by RE (Ingham et al., 2008) analysing marathon and middle-distance runners aspart of the same group would hide any existing trendfor the different events separately. Therefore, since13 of the 32 participants tested were 800- or 1500-mrunners, we would question (a) the simple methodand resultant lack of association as an artefact of thegroup and testing model and (b) whether there was abasis for testing a RE-performance hypothesis insuch different athletes in the rst instance.Ideally, what Mooses et al. (2014) might have

done is to identify which runners in the samplebelong to the middle-distance compared to long-distance category, so that either a different methodof testing or performance prediction might be used.However, we appreciate that such a distinction

would likely have decreased sample sizes to thepoint of being statistically underpowered. The treat-ment of all runners in one group may however leadto falsely concluding that RE is not related toperformance.Further method issues may also inuence the nd-

ings. One of the ndings of Mooses et al. (2014) wasthat incremental running performance to exhaustionwas not correlated with RE. However, the protocolused in this incremental test is unusual and, wewould argue, not valid for the range of athletestested. First, the speed was increased only to17 km h1, relatively slow for an elite group.Thereafter, the load was increased by means ofincreasing gradient. The data on the nal gradientsreached are not provided, but we would expect thiscalibre of athlete to reach very high gradients atwhich point the biomechanical changes of steepuphill running may begin to confound the perfor-mance as the muscle activation proles dramaticallydiffer between horizontal and uphill running(Sloniger, Cureton, Prior, & Evans, 1997).Finally, whilst this study may be the rst to sys-

tematically explore the relationships of a vast num-ber of anthropometric parameters and RE in eliteKenyan runners, it is not the rst to analyse themajor putative anthropometric parameters thatmay explain RE and running performance in ahomogenous group of competitive Kenyan runners,as is claimed. Vernillo and colleagues recentlyreported a comprehensive range of directly mea-sured anthropometrical variables, including skind-folds, upper and lower body lengths, breadths,girths and even the somatotype (Vernillo et al.,2013). They did not link these to RE, as Mooseset al. (2014) have done, but this existing contribu-tion cannot be overlooked.In conclusion, the ndings of Mooses et al. (2014)

suggest that RE alone does not explain superior dis-tance running performance in elite Kenyan runners.This was never in question, since Kenyan runningsuccess is widely accepted as a multi-factorial phe-nomenon. However, based on the methods used,and the range of athletes tested, we would questionwhether this study provides any basis for downplay-ing the inuence of RE, suggesting that other factorscompensate for it to enable superior performance.

References

Chapman, R. F., Laymon, A. S., Wilhite, D. P., McKenzie, J. M.,Tanner, D. A., & Stager, J. M. (2012). Ground contact time asan indicator of metabolic cost in elite distance runners.Medicine & Science in Sports & Exercise, 44, 917925.

Daniels, J., & Daniels, N. (1992). Running economy of elite maleand elite female runners. Medicine & Science in Sports &Exercise, 24, 483489.

2 J. Santos-Concejero & R. Tucker

Dow

nloa

ded

by [8

9.7.0.

170]

at 04

:42 29

Octo

ber 2

014

Dufeld, R., Dawson, B., & Goodman, C. (2005). Energy systemcontribution to 400-metre and 800-metre track running.Journal of Sports Sciences, 23, 299307.

Ingham, S. A., Whyte, G. P., Pedlar, C., Bailey, D. M., Dunman,N., & Nevill, A. M. (2008). Determinants of 800-m and 1500-m running performance using allometric models. Medicine &Science in Sports & Exercise, 40, 345350.

Kilding, A. E., Fysh, M., & Winter, E. M. (2007). Relationshipsbetween pulmonary oxygen uptake kinetics and other measuresof aerobic tness in middle- and long-distance runners.European Journal of Applied Physiology, 100, 105114.

La Torre, A., Vernillo, G., Agnello, L., Berardelli, C., &Rampinini, E. (2011). Is it time to consider a new performanceclassication for high-level male marathon runners? Journal ofStrength and Conditioning Research, 25, 32423247.

Larsen, H. B. (2003). Kenyan dominance in distance running.Comparative Biochemistry and Physiology Part A: Molecular &Integrative Physiology, 136, 161170.

Lucia, A., Esteve-Lanao, J., Olivn, J., Gmez-Gallego, F., SanJuan, A. F., Santiago, C., Foster, C. (2006). Physiologicalcharacteristics of the best Eritrean runners-exceptional runningeconomy. Applied Physiology & Nutrition Metabolism, 31, 530540.

Mooses, M., Mooses, K., Haile, D. W., Durussel, J., Kaasik, P., &Pitsiladis, Y. P. (2014). Dissociation between running econ-omy and running performance in elite Kenyan distance run-ners. Journal of Sports Sciences, 11, 19.

Nevill, A. M., Ramsbottom, R., Nevill, M. E., Newport, S., &Williams, C. (2008). The relative contributions of anaerobicand aerobic energy supply during track 100-, 400- and 800-m

performance. Journal of Sports Medicine & Physical Fitness, 48,138142.

Saltin, B., Larsen, H., Terrados, N., Bangsbo, J., Bak, T., Kim,C. K., Rolf, C. J. (1995). Aerobic exercise capacity at sealevel and at altitude in Kenyan boys, junior and senior runnerscompared with Scandinavian runners. Scandinavian Journal ofMedicine & Science in Sports, 5, 209221.

Saunders, P. U., Pyne, D. B., Telford, R. D., & Hawley, J. A.(2004). Factors affecting running economy in trained distancerunners. Sports Medicine, 34, 465485.

Sloniger, M. A., Cureton, K. J., Prior, B. M., & Evans, E. M.(1997). Lower extremity muscle activation during horizontal anduphill running. Journal of Applied Physiology, 83, 20732079.

Tam, E., Rossi, H., Moia, C., Berardelli, C., Rosa, G., Capelli,C., & Ferretti, G. (2012). Energetics of running in top-levelmarathon runners from Kenya. European Journal of AppliedPhysiology, 112, 37973806.

Tucker, R., Santos-Concejero, J., & Collins, M. (2013). Thegenetic basis for elite running performance. British Journal ofSports Medicine, 47, 545549.

Vernillo, G., Schena, F., Berardelli, C., Rosa, G., Galvani, C.,Maggioni, M., La Torre, A. (2013). Anthropometric char-acteristics of top-class Kenyan marathon runners. Journal ofSports Medicine & Physical Fitness, 53, 403408.

Weston, A. R., Mbambo, Z., & Myburgh, K. H. (2000). Runningeconomy of African and Caucasian distance runners. Medicine& Science in Sports & Exercise, 32, 11301134.

Wilber, R. L., & Pitsiladis, Y. P. (2012). Kenyan and Ethiopiandistance runners: What makes them so good? InternationalJournal of Sports Medicine, 7, 92102.

Running economy and performance in Kenyan runners 3

Dow

nloa

ded

by [8

9.7.0.

170]

at 04

:42 29

Octo

ber 2

014

AbstractReferences