Functional Threshold Power in Cyclists: Validity of the Concept and Physiological Responses

Abstract

Functional threshold power is defined as the highest power output a cyclist can maintain in a quasi-steady state for approximately 60 min (FTP₆₀). In order to improve practicality for regular evaluations, FTP₆₀ could theoretically be determined as 95% of the mean power output in a 20-min time trial (FTP₂₀). This study tested this assumption and the validity of FTP₂₀ and FTP₆₀ against the individual anaerobic threshold (IAT). Twenty-three trained male cyclists performed an incremental test to exhaustion, 20- and 60-min time trials, and a time to exhaustion at FTP₂₀. Power output, heart rate and oxygen uptake representing FTP₂₀, FTP₆₀ and IAT were not different (p>0.05), and large to very large correlations were found (r=0.61 to 0.88). Bland-Altman plots between FTP₂₀, FTP₆₀ and IAT showed small bias (–1 to –5 W), but large limits of agreement ([–40 to 32 W] to [–62 to 60 W]). Time to exhaustion at FTP₂₀ was 50.9±15.7 min. In conclusion, FTP₂₀ and FTP₆₀ should not be used interchangeably on an individual basis and their validity against IAT should be interpreted with caution.

Key words

cycling - time trial - performance - pacing strategy - noninvasive test - anaerobic threshold

• References

• 1 Abbiss CR, Quod MJ, Levin G, Martin DT, Laursen PB. Accuracy of the Velotron ergometer and SRM power meter. Int J Sports Med 2009; 30: 107-112
• 2 Allen H, Coggan A. Training and racing with a power meter. 2nd ed. Boulder: Velo Press; 2010
• 3 Baron B, Noakes TD, Dekerle J, Moullan F, Robin S, Matran R, Pelayo P. Why does exercise terminate at the maximal lactate steady state intensity?. Br J Sports Med 2008; 42: 828-833
• 4 Bishop D. Warm up II: performance changes following active warm up and how to structure the warm up. Sports Med 2003; 33: 483-498
• 5 Borg GA. Psychophysical bases of perceived exertion. Med Sci Sports Exerc 1982; 14: 377-381
• 6 Bossi AH, Lima P, Lima JP, Hopker J. Laboratory predictors of uphill cycling performance in trained cyclists. J Sports Sci 2017; 35: 1364-1371
• 7 Currell K, Jeukendrup AE. Validity, reliability and sensitivity of measures of sporting performance. Sports Med 2008; 38: 297-316
• 8 Davies MJ, Clark B, Welvaert M, Skorski S, Garvican-Lewis LA, Saunders P, Thompson KG. Effect of environmental and feedback interventions on pacing profiles in cycling: A meta-analysis. Front Physiol 2016; 7: 591
• 9 De Pauw K, Roelands B, Cheung SS, de Geus B, Rietjens G, Meeusen R. Guidelines to classify subject groups in sport-science research. Int J Sports Physiol Perform 2013; 8: 111-122
• 10 de Souza KM, Grossl T, Junior RJB, de Lucas RD, Costa VP, Guglielmo LGA. Maximal lactate steady state estimated by different methods of anaerobic threshold. Rev Bras Cineantropom Desempenho Hum 2012; 14: 125-275
• 11 Denham J, Scott-Hamilton J, Hagstrom AD, Gray AJ. Cycling power outputs predict functional threshold power and maximum oxygen uptake. J Strength Cond Res 2017; DOI: 10.1519/JSC.0000000000002253.
• 12 Dickhuth HH, Yin L, Niess A, Rocker K, Mayer F, Heitkamp HC, Horstmann T. Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: Relationship and reproducibility. Int J Sports Med 1999; 20: 122-127
• 13 Faude O, Kindermann W, Meyer T. Lactate threshold concepts: how valid are they?. Sports Med 2009; 39: 469-490
• 14 Gavin TP, Van Meter JB, Brophy PM, Dubis GS, Potts KN, Hickner RC. Comparison of a field-based test to estimate functional threshold power and power output at lactate threshold. J Strength Cond Res 2012; 26: 416-421
• 15 Grossl T, de Lucas RD, de Souza KM, Guglielmo LG. Time to exhaustion at intermittent maximal lactate steady state is longer than continuous cycling exercise. Appl Physiol Nutr Metab 2012; 37: 1047-1053
• 16 Harriss DJ, Macsween A, Atkinson G. Standards for ethics in sport and exercise science research: 2018 update. Int J Sports Med 2017; 38: 1126-1131
• 17 Hoefelmann CP, Diefenthaeler F, Costa VP, de Lucas RD, Shambrook P, Guglielmo LG. Test-retest reliability of second lactate turnpoint using two different criteria in competitive cyclists. Eur J Sport Sci 2015; 15: 265-270
• 18 Hofmann P, Tschakert G. Intensity- and duration-based options to regulate endurance training. Front Physiol 2017; 8: 337
• 19 Hopkins WG, Marshall SW, Batterham AM, Hanin J. Progressive statistics for studies in sports medicine and exercise science. Med Sci Sports Exerc 2009; 41: 3-13
• 20 Kuipers H, Verstappen FT, Keizer HA, Geurten P, van Kranenburg G. Variability of aerobic performance in the laboratory and its physiologic correlates. Int J Sports Med 1985; 6: 197-201
• 21 Miller MC, Moir GL, Stannard SR. Validity of using functional threshold power and intermittent power to predict cross-country mountain bike race outcome. J Sci Cycling 2014; 3: 16-20
• 22 Nimmerichter A, Eston R, Bachl N, Williams C. Effects of low and high cadence interval training on power output in flat and uphill cycling time-trialtime trials. Eur J Appl Physiol 2012; 112: 69-78
• 23 Nimmerichter A, Eston RG, Bachl N, Williams C. Longitudinal monitoring of power output and heart rate profiles in elite cyclists. J Sports Sci 2011; 29: 831-840
• 24 Nimmerichter A, Williams C, Bachl N, Eston R. Evaluation of a field test to assess performance in elite cyclists. Int J Sports Med 2010; 31: 160-166
• 25 Sanders D, Taylor RJ, Myers T, Akubat I. A field-based cycling test to assess predictors of endurance performance and establishing training zones. J Strength Cond Res 2017; DOI: 10.1519/JSC.0000000000001910.
• 26 Seiler S. What is best practice for training intensity and duration distribution in endurance athletes?. Int J Sports Physiol Perform 2010; 5: 276-291
• 27 Tomlin DL, Wenger HA. The relationship between aerobic fitness and recovery from high– intensity intermittent exercise. Sports Med 2001; 31: 1-11