Exercise Intensity of Cycle-Touring Events

Abstract

The aim of the study was to analyze the exercise intensity of recreational cyclists participating in a cycling-touring event. In 14 male healthy recreational cyclists heart rate (HR) monitoring was performed during the Ötztal Radmarathon 1999 (distance: 230 km; altitude difference: 5500 m) in order to evaluate the HR response and to estimate the cardiopulmonary strains for the less-trained athlete confronted with such a marathon. Four different exercise intensities were defined as percentages of maximal HR (HR_max) as follows: recovery HR (HR_re) < 70 % of HR_max; moderate aerobic HR (HR_ma) = 70 - 80 %; intense aerobic HR (HR_ia) = 80 - 90 %; and anaerobic HR (HR_an) > 90 %.

All athletes finished the competition successfully. The mean racing time was 10 h 14 min, the average speed 22.5 km/h. The mean HR_max was 188 bpm, the average value of the measured HRs (HR_average) was 145 bpm resulting in a mean HR_average/HR_max ratio of 0.77. Athletes spent 18.5 % (1 h 54 min) of total race time within HR_re, 28 % (2 h 52 min) within HR_ma, 39.5 % (4 h 02 min) within HR_ia, and 14 % (1 h 26 min) within HR_an. The vast majority of exercise was done under “aerobic conditions” (HR_re + HR_ma + HR_ia = 86 % or 8 h 48 min) - confirming the knowledge that the aerobic energy supply is crucial for the performance of long-term exercise. The large amount of high exercise intensities (HR_ia + HR_an = 53.5 % or 5 h 30 min), however, features the intense cardiopulmonary strains evoked by such competitions. The HR response was related to the course profile with HRs significantly declining in all subjects to an extent of 10 % during the course of race.

Our findings show that the exercise intensity borne by recreational cyclists during a cycle-touring event is high and very similar to that of professionals. With respect to the high cardiovascular strains a thorough medical screening is advisable for any participant of such an event combining both high volume and high intensity loads.

Key words

Heart rate - exercise intensity - long-term exercise - recreational cycling

References

• 1 American College of Sports Medicine .General principles of exercise prescription.  In: ACSM's guidlines for exercise and prescription. 5th ed. Baltimore (MD); Williams and Wilkins 1995: 153-176
• 2 Åstrand P Q, Saltin B. Oxygen uptake during the first minutes of heavy muscular exercise.  J Appl Physiol. 1961;  16 971-976
• 3 Boulay M R. Physiological monitoring of elite cyclists. Practical methods.  Sports Med. 1995;  20 1-11
• 4 Burke E R. Physiological characteristics of competitive cyclists.  Physician Sports Med. 1980;  8 79-84
• 5 Coyle E F, Coggan A R, Hopper M K, Walters T J. Determinants of endurance in well-trained cyclists.  J Appl Physiol. 1988;  64 2622-2630
• 6 Coyle E F, Feltner M E, Kautz S A, Mamilton M T, Montain S J, Baylor A M, Abraham L D, Petrek G W. Physiological and biomechanical factors associated with elite endurance cycling performance.  Med Sci Sports Exerc. 1991;  23 93-107
• 7 di Bello V, Talarico L, di Muro C, Santoro G, Bertini A, Giorgi D, Caputo M T, Bianchi M, Cecchini L, Giusti C. Evaluation of maximal left ventricular performance in elite bicyclists.  Int J Sports Med. 1995;  16 498-506
• 8 Fernandez-Garcia B, Perez-Landaluce J, Rodriguez-Alonso M, Terrados N. Intensity of exercise during road race pro-cycling competition.  Med Sci Sports Exerc. 2000;  32 1002-1006
• 9 García-Rovés P M, Terrados N, Fernández F, Patterson A M. Macronutrients intake of top level cyclists during continuous competition.  Int J Sports Med. 1998;  19 61-67
• 10 Gilman M B. The use of heart rate to monitor the intensity of endurance training.  Sports Med. 1996;  21 73-79
• 11 Gilman M B, Wells C L. The use of heart rates to monitor exercise intensity in relation to metabolic variables.  Int J Sports Med. 1993;  14 339-344
• 12 Hagberg J M, Mullin J P, Bahrke M, Limberg J. Physiological profiles and selected psychological characteristics of national class American cyclists.  J Sports Med. 1979;  19 341-346
• 13 Legge B J, Bannister E W. The Åstrand-Rhyming nomogram revisited.  J Appl Physiol. 1986;  61 1203-1209
• 14 Londeree B R, Moeschberger M L. Effect of age and other factors on maximal heart rate.  Res Q Exerc Sport. 1982;  53 297-303
• 15 Lucia A, Hoyos J, Carvajal A, Chicharro J L. Heart rate response to professional road cycling: The Tour de France.  Int J Sports Med. 1999;  20 167-172
• 16 Lucia A, Pardo J, Durántez A, Hoyos J, Chicharro J L. Physiological differences between elite and professional road cyclists.  Int J Sports Med. 1998;  19 342-348
• 17 Neumayr G, Gaenzer H, Pfister R, Sturm W, Schwarzacher S P, Eibl G, Mitterbauer G, Hoertnagl H. Plasma levels of cardiac troponin I after prolonged strenuous endurance exercise.  Am J Cardiol. 2001;  87 369-371
• 18 Neumayr G, Pfister R, Mitterbauer G, Gaenzer H, Joannidis M, Eibl G, Hoertnagl H. Short-term effects of prolonged strenuous endurance exercise on the level of haematocrit in amateur cyclists.  Int J Sports Med. 2002; in press; 
• 19 O'Toole M L, Douglas P S, Hiller W D. Use of heart rate monitors by endurance athletes: lessons from triathletes.  J Sports Med Phys Fitness. 1998;  38 181-187
• 20 Padilla S, Mujika I, Orbananos J, Angulo F. Exercise intensity during competition time trials in professional road cycling.  Med Sci Sports Exerc. 2000;  32 850-856
• 21 Padilla S, Mujika I, Orbananos J, Santisteban J, Angulo F, Goiriena J. Exercise intensity and load during mass-start stage races in professional road cycling.  Med Sci Sports Exerc. 2001;  33 796-802
• 22 Palmer G S, Hawley J A, Dennis S C, Noakes T D. Heart rate responses during a 4-d cycle stage race.  Med Sci Sports Exerc. 1994;  26 1278-1283
• 23 Rowe W J. Extraordinary unremitting endurance exercise and permanent injury to normal heart.  Lancet. 1992;  340 712-714
• 24 Terrados N, Maughan R J. Exercise in the heat: strategies to minimize the adverse effects on performance.  J Sports Sci. 1995;  26 183
• 25 Zavorsky G S. Evidence and possible mechanisms of altered maximum heart rate with endurance training and tapering.  Sports Med. 2000;  29 13-26