Physiological and performance characteristics of male professional road cyclists.

Male professional road cycling competitions last between 1 hour (e.g. the time trial in the World Championships) and 100 hours (e.g. the Tour de France). Although the final overall standings of a race are individual, it is undoubtedly a team sport. Professional road cyclists present with variable anthropometric values, but display impressive aerobic capacities [maximal power output 370 to 570 W, maximal oxygen uptake 4.4 to 6.4 L/min and power output at the onset of blood lactate accumulation (OBLA) 300 to 500 W]. Because of the variable anthropometric characteristics, 'specialists' have evolved within teams whose job is to perform in different terrain and racing conditions. In this respect, power outputs relative to mass exponents of 0.32 and 1 seem to be the best predictors of level ground and uphill cycling ability, respectively. However, time trial specialists have been shown to meet requirements to be top competitors in all terrain (level and uphill) and cycling conditions (individually and in a group). Based on competition heart rate measurements, time trials are raced under steady-state conditions, the shorter time trials being raced at average intensities close to OBLA (approximately 400 to 420 W), with the longer ones close to the individual lactate threshold (LT, approximately 370 to 390 W). Mass-start stages, on the other hand, are raced at low mean intensities (approximately 210 W for the flat stages, approximately 270 W for the high mountain stages), but are characterised by their intermittent nature, with cyclists spending on average 30 to 100 minutes at, and above LT, and 5 to 20 minutes at, and above OBLA.     

Metabolic recovery in professional road cyclists: a 31P-MRS study

PURPOSE: Aerobic training of professional road cyclists is linked to tremendous aerobic capacities that have never been clearly related to what occur in skeletal muscles submitted to a specific exercise. The aim of the present study was to examine specifically metabolic recovery after an incremental cycling exercise performed until exhaustion in professional road cyclists as compared with moderately trained subjects and so using 31P- MRS. METHODS: Subjects performed a progressive cycling exercise on a cycloergometer until exhaustion, then they were positioned back in the magnet (delay lower than 45 s) for recovery scanning. 31P spectra of thigh muscles were time averaged in 2-s blocks at rest and for 15 min throughout the recovery period. RESULTS: For a significantly more intense exercise (477 +/- 28 vs 334 +/- 24 W in controls; P < 0.001), professional road cyclists displayed similar end-of-exercise extrapolated pH values (6.43 +/- 0.16 vs. 6.34 +/- 0.05 in controls) and a significantly higher PCr concentration (20.1 +/- 0.8 vs. 13.3 +/- 0.5 mM in controls, P < 0.001). The pH recovery kinetics provided the evidence of metabolic adaptations related to a specific training in professional cyclists with a significantly faster rate (P < 0.01) of pH return toward basal values (32.8 +/- 18.9 vs 10.8 +/- 6.7 mM x min(-1)). On the contrary, no significant difference was measured for the PCr recovery kinetics. At rest, PDE concentration was significantly higher in professional cyclists (2.50 +/- 0.80 vs 1.76 +/- 0.42 mM), likely indicating a difference regarding fiber-type composition. DISCUSSION: The present data demonstrated for the first time that the tremendous aerobic capacity in professional cyclists is linked to faster pH recovery kinetics after a specific cycling exercise.     

An observational study of cross-cultural communication in short-term,diverse professional learning groups

This paper reports the evaluation of a European funded 3-week summer school which took place in 2013 involving 60 staff and students from five universities. The evaluation looked at one group in detail using a qualitative approach to consider whether students and teachers can work together in multicultural groups in order to achieve their goal.MethodOne group was observed during 2 two-hour sessions of group activity; at the beginning and end of the summer school task. Video data was analysed using the Rapport Management framework, a model of cross-cultural communication, to determine what motivated this group's interactions.ResultsAs the group's deadline became imminent ‘face-threatening acts’ (FTAs) were more apparent. These were tolerated in this group because of the development of a strong social bond. There was inequity in participation with members of the group falling into either high- or low-involvement categories. This was also well-tolerated but meant some students may not have gained as much from the experience. The group lacked guidance on managing group dynamics.ConclusionCultural differences in communication were not the main threat to multi-cultural working groups. Potential problems can arise from failing to provide the group with a framework for project and team management. An emphasis on ground rules and the allocation of formal roles is important as is the encouragement of socialisation which supports the group during challenging times.     

ACTN3 genotype in professional endurance cyclists

The Z-disk protein alpha-actinin-3 is only expressed in type II muscle fibres, which are responsible for generating forceful contractions at high velocity. Despite the evolutionary conservation of alpha-actinin-3, approximately one in every five Caucasians of European ancestry is totally deficient in this protein, due to homozygosity for a R577X polymorphism in the ACTN3 gene. This, together with the results of recent research on elite athletes, suggests that the "null" XX polymorphism might confer some advantage to endurance performance events. To test this hypothesis, we studied the frequency distribution of R577X genotypes in a group of 50 top-level male professional cyclists (26.9 +/- 0.4 yrs [mean +/- SEM]; VO2max: 73.5 +/- 0.8 ml x kg (-1) x min (-1)). Their results were compared with those of a group of 52 Olympic-class male endurance runners (26.8 +/- 0.6 yrs; VO2max: 73.3 +/- 0.8 ml x kg (-1) x min (-1)) and 123 healthy, sedentary male controls. All subjects were Caucasian, and of European ancestry. No significant differences (p > 0.05) were found between groups: RR: 28.5 %; RX: 53.6 % and XX: 17.9 % in controls; RR: 28.0 %; RX: 46.0 % and XX: 26.0 % in cyclists; and RR: 25.0 %; RX: 57.7 %; XX: 17.3 % in runners). No differences were found in indices of endurance performance (VO2peak or ventilatory thresholds) between athlete carriers of each R577X genotype. In summary, although the alpha-actinin-3 deficient XX genotype may be detrimental for sprint performance in humans, the R577X polymorphism of the ACTN3 gene does not appear to confer an advantage on the ability of male athletes to sustain extreme endurance performance.     

No differences in cycling efficiency between world-class and recreational cyclists

The aim of this experiment was to compare the efficiency of elite cyclists with that of trained and recreational cyclists. Male subjects (N = 69) performed an incremental exercise test to exhaustion on an electrically braked cycle ergometer. Cadence was maintained between 80 - 90 rpm. Energy expenditure was estimated from measures of oxygen uptake (VO (2)) and carbon dioxide production (VCO(2)) using stoichiometric equations. Subjects (age 26 +/- 7 yr, body mass 74.0 +/- 6.3 kg, Wpeak 359 +/- 40 W and VO(2)peak 62.3 +/- 7.0 mL/kg/min) were divided into 3 groups on the basis of their VO (2)peak (< 60.0 (Low, N = 26), 60 - 70 (Med, N = 27) and > 70 (High, N = 16) mL/kg/min). All data are mean +/- SE. Despite the wide range in aerobic capacities gross efficiency (GE) at 165 W (GE (165)), GE at the same relative intensity (GE (final)), delta efficiency (DE) and economy (EC) were similar between all groups. Mean GE (165) was 18.6 +/- 0.3 %, 18.8 +/- 0.4 % and 17.9 +/- 0.3 % while mean DE was 22.4 +/- 0.4 %, 21.6 +/- 0.4 % and 21.2 +/- 0.5 % (for Low, Medium and High, respectively). There was no correlation between GE (165), GE (final), DE or EC and VO(2)peak. Based on these data, we conclude that there are no differences in efficiency and economy between elite cyclists and recreational level cyclists.     

Characterization of hematopoietic bone marrow in male professional cyclists by magnetic resonance imaging of the lumbar spine

PURPOSE: To prospectively evaluate hematopoietic bone marrow of male professional cyclists in relation to performance data and laboratory data, and in comparison to age-matched healthy volunteers. MATERIALS AND METHODS: Twenty male cyclists and 44 volunteers (27 males and 17 females) were prospectively studied by magnetic resonance imaging (MRI) at high-field strength. A sagittal T1-weighted (T1-w) spin-echo (SE) sequence, a gradient-echo (GE) sequence with an echo time (TE) for out-of-phase (OOP) imaging, and a turbo inversion-recovery sequence with short inversion time (TIRM) for fat suppression was used. The averaged bone marrow signal intensity (SI) of three adjacent vertebrae was related to the signal of an adjacent nondegenerative disk. RESULTS: The cyclists revealed a significantly different SI as compared to male volunteers in the OOP (0.34 +/- 0.14 vs. 0.28 +/- 0.09, P < 0.05) and T1-w sequences (1.62 +/- 0.19 vs. 1.77 +/- 0.30, P < 0.05). Only in TIRM was there a significant difference compared to female volunteers (0.36 +/- 0.08 vs. 0.44 +/- 0.04, P < 0.01). MRI data of cyclists did not correlate to hemoglobin, erythrocyte, or reticulocyte counts; ferritin, relative heart volume, relative maximal power (rPmax; W/kg bw), or relative maximal oxygen consumption (VO(2)max). A borderline linear correlation was found for hematocrit (OOP: r = 0.42, P = 0.06; TIRM: r = 0.44, P = 0.06). CONCLUSION: Bone marrow hyperplasia is observed in male professional cyclists in the axial skeleton. The MR findings are probably independent of mechanically induced marrow edema. A multifactorial cause must be considered, as single laboratory and performance data did not appear to contribute significantly to these results.     

Level ground and uphill cycling ability in professional road cycling.

PURPOSE: To evaluate the physiological capacities and performance of professional road cyclists in relation to their morphotype-dependent speciality. METHODS: 24 world-class cyclists, classified as flat terrain (FT, N = 5), time trial (TT, N = 4), all terrain (AT, N = 6). and uphill (UH, N = 9) specialists, completed an incremental laboratory cycling test to assess maximal power output (Wmax), maximal oxygen uptake (VO2max), lactate threshold (LT), and onset of blood lactate accumulation (OBLA). RESULTS: UH had a higher frontal area (FA):body mass (BM) ratio (5.23 +/- 0.09 m2 x kg(-1) x 10(-3)) than FT and TT (P < 0.05). FT showed the highest absolute Wmax (481 +/- 18 W), and UH the highest Wmax relative to BM (6.47 +/- 0.33 W x kg(-1)). WLT and W(OBLA) values were significantly higher in FT (356 +/- 41 and 417 +/- 45 W) and TT (357 +/- 41 and 409 +/- 46 W) than in UH (308 +/- 46 and 356 +/- 41). Scaling of these values relative to FA and BM exponents 0.32 and 0.79 minimized group differences, but considerable differences among mean group values remained. FT and TT had the highest Wmax per FA unit (1300 +/- 62 and 1293 +/- 57 W x m2), whereas TT had the highest absolute W x kg(-0.32) and W x kg(-0.79), as well as W x kg(-0.32), W x kg(-0.79), and W x m2 at the LT and OBLA. CONCLUSIONS: i) Scaling of maximal and submaximal physiological values showed a performance advantage of TT over FT, AT, and UH in all cycling terrains and conditions; and ii) mass exponents of 0.32 and 1 were the most appropriate to evaluate level and uphill cycling ability, respectively, whereas absolute Wmax values are recommended for performance-prediction in short events on level terrain, and W(LT) and W(OBLA) in longer time trials and uphill cycling.     

Branched-chain amino acid supplementation improves cycling performance in untrained cyclists

ObjectivesTo investigate the effects of acute branched-chain amino acid (BCAA) supplementation on cycling performance and neuromuscular fatigue during a prolonged, self-paced cycling time-trial.DesignRandomised double-blind counterbalanced crossover.MethodsEighteen recreationally active men (mean ± SD; age: 24.7 ± 4.8 years old; body-weight, BW: 67.1 ± 6.1 kg; height: 171.7 ± 4.9 cm) performed a cycling time-trial on an electromagnetically-braked cycle ergometer. Participants were instructed to complete the individualised total work in the shortest time possible, while ingesting either BCAAs (pre-exercise: 0.084 g kg^?1 BW; during exercise: 0.056 g kg^?1 h^?1) or a non-caloric placebo solution. Rating of perceived exertion, power, cadence and heart rate were recorded throughout, while maximal voluntary contraction, muscle voluntary activation level and electrically evoked torque using single and doublet stimulations were assessed at baseline, immediately post-exercise and 20-min post-exercise.ResultsSupplementation with BCAA reduced (287.9 ± 549.7 s; p = 0.04) time-to-completion and ratings of perceived exertion (p ≤ 0.01), while concomitantly increasing heart rate (p = 0.02). There were no between-group differences (BCAA vs placebo) in any of the neuromuscular parameters, but significant decreases (All p ≤ 0.01) in maximal voluntary contraction, muscle voluntary activation level and electrically evoked torque (single and doublet stimulations) were recorded immediately following the trial, and these did not recover to pre-exercise values by the 20 min recovery time-point.ConclusionsCompared to a non-caloric placebo, acute BCAA supplementation significantly improved performance in cycling time-trial among recreationally active individuals without any notable changes in either central or peripheral factors. This improved performance with acute BCAA supplementation was associated with a reduced rating of perceived exertion.     

Intensity of exercise according to topography in professional cyclists

PURPOSE: The aim of the study was to analyze the intensity of effort made by professional cyclists in the different mountain passes climbed during the 1999 and 2000 Vuelta a Espa?a. METHODS: During the ascent of high mountain passes of different categories (special category (HMS), and 1st (HM1), 2nd (HM2), and 3rd category (HM3)), the response of the HR was analyzed according to three intensity zones: zone 1(Z1, above the ventilatory threshold (VT)), zone 2 (Z2, between VT and the respiratory compensation threshold (RCT)), and zone 3 (Z3, above the RCT). RESULTS: The values are presented as mean +/- SEM. Values of HR were significantly higher (P < 0.05) in HM1 (160 +/- 1 beats x min-1) compared with the other types of ascents. When we compared the different passes, the intensity decreased in the following order: HM1, HMS, HM2, and HM3. The average time that cyclists spent in Z3 was significantly higher in HM1 (10.7 +/- 1.4 min) with respect to the other categories. The time in Z2 was significantly higher in HMS and HM1 (43.1 +/- 1.5 and 44.3 +/- 3.1 min) than in HM2 and HM3 (21.6 +/- 1.1 and 11.9 +/- 1.1 min). The percentage of total time spent in Z3 was significantly higher in HM1 and HM3 (21.2 +/- 2.9 and 17.3 +/- 1.9%) than in HME and HM2.CONCLUSION: The ascent of mountain passes is an activity involving intense effort which is reflected in the time cyclists spend in Z3 and Z2, and is related to the category of the mountain passes involved.     

Torque and power-velocity relationships in cycling: relevance to track sprint performance in world-class cyclists

The aims of the present study were both to describe anthropometrics and cycling power-velocity characteristics in top-level track sprinters, and to test the hypothesis that these variables would represent interesting predictors of the 200 m track sprint cycling performance. Twelve elite cyclists volunteered to perform a torque-velocity test on a calibrated cycle ergometer, after the measurement of their lean leg volume (LLV) and frontal surface area (A(p)), in order to draw torque- and power-velocity relationships, and to evaluate the maximal power (P(max)), and both the optimal pedalling rate (f(opt)) and torque (T(opt)) at which P (max) is reached. The 200 m performances--i.e. velocity (V200) and pedalling rate (f 200)--were measured during international events (REC) and in the 2002 French Track Cycling Championships (NAT). P(max), f(opt), and T(opt) were respectively 1600 +/- 116 W, 129.8 +/- 4.7 rpm and 118.5 +/- 9.8 N . m. P(max) was strongly correlated with T(opt) (p < 0.001), which was correlated with LLV (p < 0.01). V200 was related to P(max) normalized by A(p) (p < or = 0.05) and also to f(opt) (p < 0.01) for REC and NAT. f 200 (155.2 +/- 3, REC; 149 +/- 4.3, NAT) were significantly higher than f(opt) (p < 0.001). These findings demonstrated that, in this population of world-class track cyclists, the optimization of the ratio between P(max) and A(p) represents a key factor of 200 m performance. Concerning the major role also played by f(opt), it is assumed that, considering high values of f 200, sprinters with a high value of optimal pedalling rate (i.e. lower f200-f(opt) difference) could be theoretically in better conditions to maximize their power output during the race and hence performance.     

The slow component of VO2 in professional cyclists

OBJECTIVES: To analyse the slow component of oxygen uptake (VO2) in professional cyclists and to determine whether this phenomenon is due to altered neuromuscular activity, as assessed by surface electromyography (EMG). METHODS: The following variables were measured during 20 minute cycle ergometer tests performed at about 80% of VO2MAX in nine professional road cyclists (mean (SD) age 26 (2) years; VO2max 72.6 (2.2) ml/kg/min): heart rate (HR), gas exchange variables (VO2, ventilation (VE), tidal volume (VT), breathing frequency (fb), ventilatory equivalents for oxygen and carbon dioxide (VE/VO2 and VE/VCO2 respectively), respiratory exchange ratio (RER), and end tidal PO2 and PCO2 (PETO2 and PETCO2 respectively)), blood variables (lactate, pH, and [HCO3-]) and EMG data (root mean from square voltage (rms-EMG) and mean power frequency (MPF)) from the vastus lateralis muscle. RESULTS: The mean magnitude of the slow component (from the end of the third minute to the end of exercise) was 130 (0.04) ml in 17 minutes or 7.6 ml/min. Significant increases from three minute to end of exercise values were found for the following variables: VO2 (p<0.01), HR (p<0.01), VE (p<0.05), fb (p<0.01), VE/VO2 (p<0.05), VE/VCO2 (p<0.01), PETO2 (p<0.05), and blood lactate (p<0.05). In contrast, rms-EMG and MPF showed no change (p>0.05) throughout the exercise tests. CONCLUSIONS: A significant but small VO2 slow component was shown in professional cyclists during constant load heavy exercise. The results suggest that the primary origin of the slow component is not neuromuscular factors in these subjects, at least for exercise intensities up to 80% of VO2MAX.     

Myocardial stress after competitive exercise in professional road cyclists

PURPOSE: Based on the determination of cardiac troponin (cTnT), brain natriuretic peptide (BNP), and echocardiographic measurements, recent investigations have reported myocardial damage and reversible cardiac dysfunction after prolonged endurance exercise in apparently healthy subjects. In the present study, we investigated the myocardial stress reaction in professional endurance athletes after strenuous competitive physical exercise. METHODS: Eleven highly trained male professional road cyclists (age 27 +/- 4 yr; .VO2peak 67 +/- 5 mL.kg-1.min-1; training workload 34,000 +/- 2,500 km.yr-1) were examined. The following parameters were determined before and after one stage of a 5-d professional cycling race: BNP, cTnT (third-generation assay that shows no cross reactivity with skeletal TnT), creatine kinase (CK), creatine kinase MB (CKMB), myoglobin (Myo), and urea. All participants were submitted to a careful cardiac examination including echocardiography and stress ECG. RESULTS: None of the athletes showed pathological findings in the cardiac examination. CK (P < 0.01), CKMB (P < 0.05), and Myo (P < 0.01) were increased after the race. Normal postexercise cTnT levels indicate that the increase in CK, CKMB, and Myo was of noncardiac origin. In contrast, BNP rose significantly from 47.5 +/- 37.5 to 75.3 +/- 55.3 pg.mL-1 (P < 0.01). Pre- and postexercise values of BNP as well as the individual exercise-induced increase in BNP were significantly correlated with age (R2 = 0.68, R2 = 0.66, and R2 = 0.58, respectively; P < 0.05). CONCLUSION: Strenuous endurance exercise in professional road cyclists does not result in structural myocardial damage. The rise in BNP in older athletes may reflect a reversible, mainly diastolic left ventricular dysfunction. This needs to be confirmed by larger trials including different intensities, sports, and age groups.     

Kinetics of VO(2) in professional cyclists

PURPOSE: To analyze the kinetics of oxygen uptake (VO(2)) in professional road cyclists during a ramp cycle ergometer test and to compare the results with those derived from well-trained amateur cyclists. METHODS: Twelve professional cyclists (P group; 25 +/- 1 yr; maximal power output (W(max)), 508.3 +/- 9.3 watts) and 10 amateur cyclists (A group; 22 +/- 1 y; W(max), 429.9 +/- 8.6 watts) performed a ramp test until exhaustion (power output increases of 25 watts x min(-1)). The regression lines of the VO(2):power output (W) relationship were calculated for the following three phases: phase I (below the lactate threshold (LT)), phase II (between LT and the respiratory compensation point (RCP)), and phase III (above RCP). RESULTS: In group P, the mean slope (Delta VO(2):Delta W) of the VO(2):W relationship decreased significantly (P < 0.01) across the three phases (9.9 +/- 0.1, 8.9 +/- 0.2, and 3.8 +/- 0.6 mL O(2) x watts(-1) x min(-1) for phases I, II, and III, respectively). No significant differences (P > 0.05) were found between phases I and II (P > 0.05) in group A, whereas Delta VO(2):Delta W significantly increased in phase III (P < 0.01), compared with phase II (10.2 +/- 0.3, 9.2 +/- 0.4, and 10.1 +/- 1.1 mL O(2) x watts(-1) x min(-1) in phases I, II, and III, respectively). The mean value of Delta VO(2):Delta W for phase III was significantly lower in group P than in group A (P < 0.01). CONCLUSION: Contrary to the case in amateur riders, the rise in VO(2) in professional cyclists is attenuated at moderate to high workloads. This is possibly an adaptation to the higher demands of their training/competition schedule.     

Preferred pedalling cadence in professional cycling

PURPOSE: The aim of this investigation was to evaluate the preferred cycling cadence of professional riders during competition. METHODS: We measured the cadence of seven professional cyclists (28 +/- 1 yr) during 3-wk road races (Giro d'Italia, Tour de France, and Vuelta a Espa?a) involving three main competition requirements: uphill cycling (high mountain passes of approximately 15 km, or HM); individual time trials of approximately 50 km on level ground (TT); and flat, long ( approximately 190 km) group stages (F). Heart rate (HR) data were also recorded as an indicator of exercise intensity during HM, TT, and F. RESULTS: Mean cadence was significantly lower (P < 0.01) during HM (71.0 +/- 1.4 rpm) than either F and TT (89.3 +/- 1.0 and 92.4 +/- 1.3 rpm, respectively). HR was similar during HM and TT (157 +/- 4 and 158 +/- 3 bpm) and in both cases higher (P < 0.01) than during F (124 +/- 2 bpm). CONCLUSION: During both F and TT, professional riders spontaneously adopt higher cadences (around 90 rpm) than those previously reported in the majority of laboratory studies as being the most economical. In contrast, during HM they seem to adopt a more economical pedalling rate (approximately 70 rpm), possibly as a result of the specific demands of this competition phase.     

Racing weight and resistance training: perceptions and practices in trained male cyclists

ABSTRACT

Objectives: This study sought to investigate the perceptions and practices of achieving ‘race weight’ in a population of trained male cyclists. A secondary focus was to investigate the use of gym-based strength training, a possible attenuator of the side effects associated with weight reduction.

Methods: A total of n = 97 well-trained cyclists ranging from local club level to international standard completed an online survey capturing data on the aforementioned topics.

Results: Forty-nine percent of respondents indicated they were unsatisfied with their current bodyweight, with a similar percentage across club, national and international level riders. Riders who identified as climbers had lower reported bodyweight; however, all categories of riders expressed a desire to reduce bodyweight by a similar percentage (1.9%, ± 3.4%; 90% CL). Seventy-seven percent of respondents indicated that they had recently tried or were currently trying to reduce bodyweight, most commonly by reducing food intake and avoiding sugary foods. Nine percent indicated they were using either supplements or medications to lower bodyweight, and 27% reported having sought advice from a health professional. A higher proportion of international riders engaged in strength training (85%), compared to national (50%) and club (55%) riders (p< 0.05). The most cited reasons for not strength training were time constraints and believing it was not beneficial to their cycling performance.

Conclusion: These data suggest that trained male cyclists are a highly weight-conscious population who engage in a variety of practices to reduce weight. Practitioners should be aware of these tendencies, as they may carry significant health implications if poorly implemented.     

Caffeine ingestion prior to incremental cycling to exhaustion in recreational cyclists

Nine male recreational cyclist served as subjects in this experiment which included a control, placebo and caffeine trial. The aim of the experiment was to determine whether a 10 mg.kg-1 dose of caffeine given three hours prior to an incremental cycle ergometer exercise test, for caffeine naive subjects, would increase the time to exhaustion and therefore increase the amount of work undertaken by the cyclists. The cyclists initially worked at 100 watts for three minutes and then increased the workload by 50 watts every three minutes until exhaustion. Blood was drawn at the beginning of the test and every three minutes from an ante-cubital vein and was analysed for blood lactate, glucose and free fatty acids (FFA). Respiratory analysis was also undertaken and heart rate was monitored throughout the test. Subjects in the caffeine trial worked significantly longer and performed more work (p less than 0.05) than they did in either the control or placebo trials. FFA's were also significantly higher in this trial (p less than 0.05) and the lactate threshold was moved to the right as a percentage of the VO2max, which suggests less acidity and a decreased bicarbonate flushing. The respiratory exchange ratio data was significantly lowered (p less than 0.05) during workloads between 250 and 450 watts. No changes were seen in blood glucose or heart rates during the experiment. In conclusion, we feel that a 10 mg.kg-1 dose of caffeine is an ergogenic aid during incremental exercise when it is taken 3-4 hours prior to the exercise in fasting subjects who have diets low in caffeine.     

Evolution of physiological and haematological parameters with training load in elite male road cyclists: a longitudinal study

AIM: The aim of this study was to describe and evaluate physiological parameters as a control tool for the monitoring of training in a group of elite cyclists during one season of training. METHODS: The study is divided into two periods (winter or 'volume' mesocycle and spring or 'intensity' mesocycle) between the tests that they carried out in the laboratory, consisting of a ramp test to exhaustion (work load increases 25 W X min(-1)) and a maximal lactate steady state (MLSS) test on a cycle ergometer. Macronutrients and hematological variables were recorded during the test periods as were the volume and the intensity of training sessions during the whole period of the study. RESULTS: The physiological data were similar to those previously reported for professional cyclists (approximately 450 Watts, approximately 78 mL x kg(-1) x min(-1)) and the values for the MLSS also agree with previous studies (approximately 250 Watts). Subjects improved the first ventilatory threshold (VT(1)) (approximately 52% to approximately 60% VO(2max)) and the second ventilatory threshold (VT(2)) (approximately 82% to approximately 87% VO(2max)) after the first period of training even though its low intensity focused on the performance of VT(1) (77% training in 'zone 1', under VT(1)). The MLSS improved after the first period (approximately 225 to approximately 250 Watts) and remained high in the second (approximately 255 Watts). High levels of creatine kinase (approximately 230 U x L(-1)) and urea (37 mg x L(-1)) were found, also a decrease in hemoglobin values (approximately 15.4 to approximately 14.7g x dL(-1)). CONCLUSION: The high level reached by the subjects after the first period of training suggests that two effort tests could be enough to plan training. On the other hand, the decrease in some red blood cell and nutrition parameters suggests that there should be greater control over them during the season.