Current methods, concepts and theories regarding mobile power meters in cycling A critical review of the physiological and pedagogical implications for training, racing and performance testing Student: Fredrik Ericsson Kopparvägen 49B 791 41 Falun 0707-797169 [email protected] Supervisor (Exercise physiology): Michail Tonkonogi, Högskolan Dalarna Supervisor (Sports Pedagogy): Tommy Gustavsson, Högskolan Dalarna Abstract Aim This critical review is aimed at the methods, concepts and theories currently employed and advocated by users of mobile power meters (PM) in cycling and the physiological and pedagogical implications they have for training, racing and performance testing. Method The methods, concepts and theories reviewed were chosen since they generated the most hits from a search on the Google Groups Wattage (http://groups.google.com/group/wattage) discussion forum, which is the largest internet forum for PM-related discussions. After the selection of methods, concepts and theories a search in the data bases available at College of Dalarna was made to find if they had any support in the scientific literature. Results The methods, concepts and theories included are: 1. Pacing strategy and racing tactics 2. General considerations for performance testing with a PM. Tests for alactic anaerobic and maximal neuromuscular power, anaerobic lactic power, maximal aerobic power and power related to VO2max and anaerobic threshold power. Performance profiling, scaling and ratios for power output and interpreting changes in testing results. 3. Quantifying the power output demands of racing for designing training programs and other preparations. 4. Andrew Coggans and Richard Sterns power based training zones and the relationship between power output and perceived exertion. 5. Analysis of training and racing power output with tools such as Normalized Power™, Intensity Factor™, Quadrant Analysis™, energy expenditure and how pedaling dynamics affect this analysis. 6. Planning, monitoring and managing the training process with tools such as Training Stress Score™, Performance Manager Chart™ and “power-to-heart rate decoupling”. 7. Theoretical basis for the role of the PM in the inter-personal and intra-personal communication. Conclusions This review has shown that there are several very promising methods, concepts and theories related to the use of PM’s in cycling. Presently, however, most of these are in need of further research to investigate their affect on performance and how to improve their validity and reliability. Sammanfattning Syfte Den här forskningsöversikten syftar till att undersöka de metoder, praktiker och teorier som för närvarande används och förespråkas gällande effektmätare (PM) inom cykelsport samt vilken fysiologisk och pedagogisk betydelse dessa har för träning, tävling och testning. Metod Metoderna, praktikerna och teorierna som undersöks blev utvalda för att de gav flest träffar vid en sökning på Google Groups Wattage diskussionsforum (http://groups.google.com/group/wattage), som är det största forumet på internet för diskussioner rörande effektmätare. Efter att metoder, praktiker och teorier valts, genomfördes en sökning i de vetenskapliga databaser tillgängliga på Högskolan Dalarna för att undersöka vilket stöd dessa har i den vetenskapliga litteraturen. Resultat Metoderna, praktikerna och teorierna som inkluderades är: 1. Farthållningsstrategier och tävlingstaktik. 2. Generella riktlinjer för prestationstester med effektmätare. Tester för alaktacid anaerob och maximal neuromuskulär effekt, anaerob laktacid effekt, maximal aerob effekt och effekten vid VO2max samt effekten vid anaerob tröskel. Kapacitets profilering, skalor och förhållanden för effektutveckling och hur man tolkar dessa resultat. 3. Kvantifiering av effektutvecklingen vid tävling som stöd för att utveckla träningsprogram och övriga förberedelser. 4. Andrew Coggans och Richard Sterns effektbaserade träningszoner samt förhållandet mellan effektutveckling och upplevd ansträngning. 5. Analysering av träning och tävling genom verktyg som Normalized Power™, Intensity Factor™, Quadrant Analysis™, energianvändning och hur faktorer gällande tramptaget påverkar dessa. 6. Planering, övervakning och styrning av träningsprocessen med hjälp av verktyg som Training Stress Score™, Performance Manager Chart™ och förhållandet mellan effektutveckling och puls. 7. Teoretisk bas för effektmätarens roll för inter- och intrapersonell kommunikation. Slutsatser Den här översikten har visat att det finns flera lovande metoder, praktiker och teorier kopplade till effektmätning inom cykelsporten. Däremot, är de flesta av dessa för tillfället i behov av ytterligare forskning och utveckling för att undersöka deras inverkan på prestationen samt förfina deras validitet och reliabilitet. Table of contents 1. Introduction and background 1 2. Aim and research question 4 3. Method 5 Data collection and material 5 Ethical considerations 8 4. Results, discussion and conclusions 9 5. Pacing strategy and racing tactics 9 Pacing strategy 9 Racing tactics 13 Conclusions 14 6. Performance testing 16 General on testing 16 Field based testing using a PM 18 Smallest worthwhile enhancement 20 Maximal neuromuscular and anaerobic alactic performance 23 Inertial-load test 23 Anaerobic lactic 30 Field based Wingate testing using a PM 31 Anaerobic Work Capacity (AWC) 33 Maximal aerobic power 36 Anaerobic threshold 37 Critical Power 39 3min all-out field test 40 Performance profiling 40 Scaling, ratios and changes 43 Conclusions 46 7. Quantifying the demands of competition 47 Conclusions 50 8. Power-based training zones 51 Coggan training zones 52 Stern training zones 53 The relationship between power output and perceived exertion 54 Conclusions 55 9. Analysis of training and racing 56 Normalized Power™ (NP) 56 NP-busters 57 Intensity Factor™ (IF) 58 Energy expenditure 58 Pedaling dynamics 59 Quadrant Analysis™ 62 Conclusions 65 10. Planning and monitoring the training process 66 Training Stress Score™ (TSS) 66 Performance Manager Chart™ (PMC) 68 Managing training load and fatigue with the PMC 73 Power-to-heart rate decoupling 75 Conclusions 76 11. Power meters in the inter-personal communication between coach and rider 78 Role and style of the coach 78 The structure and parts of the coaching process 80 Using a PM to increase the likeliness of achieving “flow” 93 Conclusions 95 12. Power meters in the riders intra-personal communication 96 Interoception, perceived exertion and pacing 96 Power meters as an aid for motor learning 98 Conclusions 101 13. Testing the theoretical framework for inter- and intra-personal communication with PM’s102 Conclusions 105 14. Summary of results 106 15. Discussion regarding methodology 108 References 109 Scientific articles 109 Non-scientific and quasi-scientific references 125 Books 125 Web sites 126 Material from conferences and symposiums 127 Tables and figures Table 1 6 Figure 1 24 Figure 2 25 Figure 3 28 Figure 4 34 Figure 5 41 Table 2 47 Table 3 52 Table 4 53 Figure 6 63 Figure 7 65 Figure 8 72 Table 5 102 Table 6 106 Table 7 107 Apendix 1 Survey on pedagogical applications of power meters 1. Introduction and background Research in cycling, in areas such as exercise physiology, sports psychology, training- and coaching methodology, biomechanics and aerodynamics, has increased exponentially the last decades, and doesn’t seem to diminish (Burke 2003, Faria et al 2005a and Faria et al 2005b). A scientific approach to training in cycling was actually almost taboo up until the late 1980’s (Jeukendrup 2002). At the moment, one of the biggest advances when it comes to research and training in the sport of cycling is the use of mobile on-bike power meters (PM), which make accurate measurement of the work load possible in the field (Wooles et al 2005) and enables the possibility of new and advanced post-ride analysis. 103000 hits on Google when searching for “power meter” and cycling (2008-10-12) shows the popularity of this new technology. The riders’ muscles can be seen as transformers of chemical energy (phosphorylated bonds) into mechanical energy (power output) (Billat et al 1999), which is then measured with the PM. The speed of a rider is a supply and demand function between the power output of the rider and the resisting forces acting against the same rider (e.g. aerodynamic drag, rolling resistance and gravity). The demand side is affected by many factors such as equipment, bike positioning, bike handling skills, positioning in the peloton (a group of riders) and individual and team tactics (Olds 2001). Bassett et al (1999) has calculated that, in the world hour record, 60% of the improvement to date has come from improved aerodynamics and 40% from increased ability of the rider. Thus, the competitive results are not always a result of the actual performance of the rider, i.e. power output. Knowledge of result is therefore not a valid prediction of changes in performance in most cycling disciplines and PM’s are extremely valuable as they give the rider true knowledge of performance (Rose 1999). Cycling is unique in this way as it is at the moment the only outdoor sport where accurate measurement of workload capacity, i.e. power output, is possible in the field. The beauty of power output is that it is the total product of physiological and psychological capacity and thus the functional capacity of the cyclist. In for example weight lifting it is possible to quantify training by measuring exactly how much weight is being lifted and how many times (repetitions).