Increase Characteristics of the Cumulated Excess-CO₂ and the Lactate Concentration During Exercise

The so-called excess-CO₂ in physical exertion results stoichiometrically directly from the quantity of protons bound in bicarbonate buffering. This situation is used in determining the ventilatory threshold (VT). However, the extent to which the degree and increase characteristics of excess-CO₂ can be used as an equivalent to blood lactate concentrations is uncertain. To investigate this relationship, 21 healthy men exercised on a cycle ergometer (starting at 50 watt, increases of 50 watt every 3 minutes) to subjective exhaustion. To evaluate the characteristics of this increase, a slope constant λ was calculated in relation to performance for both the blood lactate concentration (λ lactate) and the cumulated excess-CO₂ (λ CO₂excess). The start of the lactate increase (LT) and excess-CO₂ (VT) showed good intercorrelation (VT = 2.27 + 0.98 · LT; r = 0.914; P < 0.001). Mean λ lactate and λ CO₂ excess were of similar dimensions in all subjects (69.3 ± 39.8 watt vs. 80.11 ± 15.7 watt), but a minority of the subjects (n = 7) showed a considerably more gradual increase for the excess-CO₂ to the maximum. Since in addition there was no significant correlation between the absolute values for maximum lactate concentrations and the cumulative excess-CO₂, an interindividual prediction of lactate concentrations from the excess-CO₂ would be difficult. It is an open question, however, whether perhaps additional performance-limiting factors, such as the ventilation or the buffering capacity, may be included when measuring the excess-CO₂ so that this parameter could be more a measure for the formation rate of new lactate than the blood lactate concentration alone.

Key words:

Exercise, testing, carbon dioxide, bicarbonate, ventilatory threshold, metabolic acidosis.

References

• 1 Barstow T J, Landaw E M, Springer C, Cooper D M. Increase in bicarbonate stores with exercise.  Respir Physiol. 1992;  87 231-242
• 2 Beaver W, Wasserman K. Muscle pH and lactate accumulation from analysis of the V˙CO₂-V˙O₂ relationship during exercise.  Clin J Sport Med. 1991;  1 27-34
• 3 Beaver W L, Wasserman K, Whipp B J. Bicarbonate buffering of lactic acid generated during exercise.  J Appl Physiol. 1986;  60 472-478
• 4 Beaver W L, Wasserman K, Whipp B J. A new method for detecting anaerobic threshold by gas exchange.  J Appl Physiol. 1986;  60 2020-2027
• 5 Beneke R. Anaerobic threshold, individual anaerobic threshold, and maximal lactate steady state in rowing.  Med Sci Sports Exerc. 1995;  27 863-867
• 6 Berg A, Spath M, Rokitzki L, Staiger J, Keul J. Influence of symptom-limited stress on blood lactate behaviour in coronary heart disease (CHD) patients.  Eur Heart J. 1987;  8 71-75
• 7 Brooks G A. Current concepts in lactate exchange.  Med Sci Sports Exerc. 1991;  23 895-906
• 8 Brooks G A, Dubouchaud H, Brown M, Sicurello J P, Butz C E. Role of mitochondrial lactate dehydrogenase and lactate oxidation in the intracellular lactate shuttle.  Proc Natl Acad Sci. 1999;  96 1129-1134
• 9 Brooks G A, Gaesser G A. End points of lactate and glucose metabolism after exhausting exercise.  J Appl Physiol. 1980;  49 1057-1069
• 10 Casaburi R, Wasserman K, Patessio A, Ioli F, Zanaboni S, Donner C F. A new perspective in pulmonary rehabilitation: anaerobic threshold as a discriminant in training.  Eur Respir J Suppl. 1989;  7 618 S-623 S
• 11 Coen B, Schwarz L, Urhausen A, Kindermann W. Control of training in middle- and long-distance running by means of the individual anaerobic threshold.  Int J Sports Med. 1991;  12 519-524
• 12 Coplan N L, Gleim G W, Nicholas J A. Principles of exercise prescription for patients with coronary artery disease.  Am Heart J. 1986;  112 145-149
• 13 Davis J A. Anaerobic threshold: review of the concept and directions for future research.  Med Sci Sports Exerc. 1985;  17 6-21
• 14 Dickhuth H H, Yin L, Niess A, Rocker K, Mayer F, Heitkamp H C, Horstmann T. Ventilatory, lactate-derived and catecholamine thresholds during incremental treadmill running: relationship and reproducibility.  Int J Sports Med. 1999;  20 122-127
• 15 Farrell P A, Wilmore J H, Coyle E F, Billing J E, Costill D L. Plasma lactate accumulation and distance running performance.  Med Sci Sports Exerc. 1979;  11 338-344
• 16 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
• 17 Heck H, Mader A, Hess G, Mücke S, Müller R, Hollman W. Justification of the 4 mmol/l lactate threshold.  Int J Sports Med. 1985;  6 117-130
• 18 Held T, Marti B. Substantial influence of level of endurance capacity on the association of perceived exertion with blood lactate accumulation.  Int J Sports Med. 1999;  20 34-39
• 19 Hirakoba K, Maruyama A, Inaki M, Misaka K. Effect of endurance training on excessive CO₂ expiration due to lactate production in exercise.  Eur J Appl Physiol. 1992;  64 73-77
• 20 Hirakoba K, Maruyama A, Misaka K. Prediction of blood lactate accumulation from excess CO₂ output during constant exercise.  Appl Human Sci. 1996;  15 205-210
• 21 Hoogeveen A R, Schep G. The plasma lactate response to exercise and endurance performance: relationships in elite triathletes (see comments).  Int J Sports Med. 1997;  18 526-530
• 22 Howley E T, Bassett D R, Welch H G. Criteria for Maximal Oxygen-Uptake - Review and Commentary.  Med Sci Sport Exerc. 1995;  27 1292-1301
• 23 Kindermann W, Schramm M, Keul J. Aerobic performance diagnostics with different experimental settings.  Int J Sports Med. 1980;  1 110-114
• 24 Kolkhorst F W, Mittelstadt S W, Dolgener F A. Perceived exertion and blood lactate concentration during graded treadmill running.  Eur J Appl Physiol. 1996;  72 272-277
• 25 Marquardt D. An algorithm for least-squares estimation of nonlinear parameters.  J Soc Indust Appl Math. 1963;  II 431-441
• 26 Roecker K, Striegel H, Freund T, Dickhuth H H. Relative functional buffering capacity in 400 m runners, long-distance runners and untrained individuals.  Eur J Appl Physiol. 1994;  68 430-434
• 27 Roecker K, Schotte O, Niess A M, Horstmann T, Dickhuth H H. Predicting competition performance in long-distance running by means of a treadmill test.  Med Sci Sports Exerc. 1998;  30 1552-1557
• 28 Snyder A C, Woulfe T, Welsh R, Foster C. A simplified approach to estimating the maximal lactate steady state.  Int J Sports Med. 1994;  15 27-31
• 29 Steed J, Gaesser G A, Weltman A. Rating of perceived exertion and blood lactate concentration during submaximal running.  Med Sci Sports Exerc. 1994;  26 797-803
• 30 Stegmann H, Kindermann W. Comparison of prolonged exercise tests at the individual anaerobic threshold and the fixed anaerobic threshold of 4 mmol × l^-1 lactate.  Int J Sports Med. 1982;  3 105-110
• 31 Stegmann H, Kindermann W, Schnabel A. Lactate kinetics and individual anaerobic threshold.  Int J Sports Med. 1981;  2 160-164
• 32 Urhausen A, Coen B, Weiler B, Kindermann W. Individual anaerobic threshold and maximum lactate steady state.  Int J Sports Med. 1993;  14 134-139
• 33 Wasserman K, McIllroy M. Detection of anaerobic metabolism in cardiac patients during exercise.  Am J Cardiol. 1964;  14 844-852
• 34 Wasserman K, Whipp B J, Koyl S N, Beaver W L. Anaerobic threshold and respiratory gas exchange during exercise.  J Appl Physiol. 1973;  35 236-243
• 35 Weltman A. The lactate threshold and endurance performance. In: Gana W (ed) Advances in Sports Medicine and Fitness. Chicago, IL; 1988