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.     

Reliability of performance in repeated sprint cycling tests

We have estimated the reliability of performance in a commonly employed exercise test consisting of repeated sprints on a cycle ergometer. Eight recreationally active young men completed a practice trial and three more trials at 3- to 6-day intervals. Each trial consisted of two bouts of 30-s maximal-effort cycling on an electromagnetically braked cycle ergometer; the bouts were separated by 4 min of rest. The typical (standard) errors of measurement for peak and mean power between trials 2 to 4 were 2.5 and 1.7% respectively for the first bout and 1.9 and 1.8% for the second bout. These errors are substantially less than those in previous reliability studies of single 30-s sprint tests, probably because of differences in quality of ergometer. The typical errors for the difference between bouts (i.e., fatigue) for peak power and mean power were 3.0 and 2.5%, respectively. Typical errors for the average of the two bouts were 1.6 and 1.2% for peak and mean power respectively, which are small enough to give adequate precision for moderate treatment effects in studies with modest sample sizes.     

Sodium bicarbonate improves sprint performance in endurance cycling

ObjectivesOral sodium bicarbonate intake (NaHCO₃) may improve performance in short maximal exercise by inducing metabolic alkalosis. However, it remains unknown whether NaHCO₃ also enhances all-out performance at the end of an endurance competition. Therefore, the present study investigated the effect of stacked NaHCO₃ loading on sprint performance following a 3-h simulated cycling race.DesignDouble-blind randomized placebo-controlled cross-over study.MethodsEleven trained male cyclists (22.3 (18.3–25.3) year; 73.0 (61.5–88) kg; VO₂max: 63.7 (57–72) ml kg^?1 min^?1) ingested either 300 mg kg^?1 body weight NaHCO₃ (BIC) or NaCl (PL). NaHCO₃ or NaCl was supplemented prior to (150 mg kg^?1) and during (150 mg kg^?1) a 3-h simulated cycling race with a 90-s all-out sprint (90S) at the end. Capillary blood samples were collected for determination of blood pH, lactate and HCO₃^? concentrations. Analysis of variance (lactate, pH, HCO₃^?) and paired t-test (power) were applied to compare variables across condition (and time).ResultsNaHCO₃ intake improved mean power during 90S by ～3% (541 ± 59 W vs. 524 ± 57 W in PL, p = 0.047, Cohen’s D = 0.28, medium). Peak blood lactate concentration and heart rate at the end of 90S were higher (p < 0.05) in BIC (16.2 ± 4.1 mmol l ¹, 184 ± 7 bpm) than in PL (12.4 ± 4.2 mmol l^?1, 181 ± 5 bpm). NaHCO₃ ingestion increased blood [HCO₃^?] (31.5 ± 1.3 vs. 24.4 ± 1.5 mmol l^?1 in PL, p < 0.001) and blood pH (7.50 ± 0.01 vs. 7.41 ± 0.03 in PL, p < 0.05) prior to 90S.ConclusionsNaHCO₃ supplementation prior and during endurance exercise improves short all-out exercise performance at the end of the event. Therefore, sodium bicarbonate intake can be applied as a strategy to increase success rate in endurance competitions.     

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.     

Metabolic and performance effects of warm-up intensity on sprint cycling

Warm-up is generally considered beneficial for performance, although the reduction in anaerobic glycolytic metabolism may be detrimental to sprinting. This study examined the effect of warm-up intensity on metabolism and performance in sprint cycling. The mean power was determined during a 1-min sprint on 11 trained males preceded by easy (WE), moderate (WM) or hard (WH) warm-up and a 10-min recovery. Aerobic, anaerobic glycolytic and phosphocreatine energy provision to the sprint was determined from oxygen uptake and lactate production. Blood lactate concentration before the sprint increased with the warm-up intensity (WE: 1.2±0.3; WM: 2.0±0.3; WH: 4.2±0.9 mmol/L, P<0.001), with WH reducing the increase in lactate production during exercise vs WE (WE: 11.6±1.6; WM: 10.9±1.9; WH: 9.2±1.4 mmol/L, P<0.05). Despite the lower relative anaerobic glycolytic energy provision in WH vs WE (WH: 38±5; WM: 36±6; WE: 34±3%, P<0.05), the mean power was unaffected (WE: 516±28; WM: 521±26; WH: 526±34 W, P>0.05) due to increased oxygen uptake in WH during the sprint (WE: 3.2±0.4; WM: 3.3±0.3; WH: 3.4±0.4 liters, P<0.05). This study supports a warm-up-induced reduction in glycolytic rate, although sprint performance, at least of a long duration, may be maintained due to increased oxygen utilization.     

Development of peak performance in track cycling.

BACKGROUND: Retrospective analysis of peak performances can be a usefull tool for the estimation of future trends in high performance sports. The purpose of this study was to investigate the evolution of performance in track cycling from 1979 to 1999 and to asses age- and gender-related differences. METHODS: We studied the results of the world track cycling championships for this period in 200 m, 1000 m, individual and team pursuit races for elite and junior athletes. Overall trends, performance differences between rank 1 and 5, gender- and age-related differences were calculated. RESULTS: They show a significant (p<0.01) improvement in 1000 m, individual and team pursuit times for men and individual pursuit times for women. No significant evolution was seen in 200 m performance. In junior riders, only male athletes showed a continuous, significant improvement of average race speed in individual and team pursuit over the study period. Gender difference was 11+/-1.8% in all disciplines at all ages. Difference between elite and junior riders ranged between 5+/-2.1% for male and 6.1+/-2.2% for female athletes. The gap between rank 1 and 5 remained constant (2-3%) over the study period. CONCLUSIONS: A continuous improvement of performance over the last 20 years is visible in track cycling endurance disciplines. New technical developments show no statistical significant impact. The performance gap between male and female athletes is constant, independent of discipline or race distance and comparable to observations in other sports. Age-related differences in performance is most visible in disciplines requiring short, high intensity power output. Based on these data, estimation of possible winning times and adaptation of training programs for future track cycling competitions might be facilitated.     

Sodium phosphate loading improves laboratory cycling time-trial performance in trained cyclists

Sodium phosphate loading has been reported to increase maximal oxygen uptake (6–12%), however its influence on endurance performance has been ambiguous. The aim of this study was to examine the influence of sodium phosphate loading on laboratory 16.1 km cycling time-trial performance. Six trained male cyclists ( peak, 64.1 ± 2.8 ml kg⁻¹ min⁻¹; mean ± S.D.) took part in a randomised double-blind crossover study. Upon completion of a control trial (C), participants ingested either 1 g of tribasic dodecahydrate sodium phosphate (SP) or lactose placebo (P) four times daily for 6 days prior to performing a 16.1 km (10 mile) cycling time-trial under laboratory conditions. Power output and heart rate were continually recorded throughout each test, and at two points during each time-trial expired air samples and capillary blood samples were taken. There was a 14-day period between each of the supplemented time-trials. After SP loading mean power was greater than for P and C (C, 322 ± 15 W; P, 317 ± 16 W; SP, 347 ± 19 W; ANOVA, P < 0.05) and time to complete the 16.1 km was shorter than P, but not C (ANOVA, P < 0.05). During the SP trial, relative to the P, mean changes were mean power output +9.8 ± 8.0% (±95% confidence interval); time −3.0 ± 2.9%. There was a tendency towards higher after SP loading (ANOVA, P = 0.07). Heart rate, , RER and blood lactate concentration were not significantly affected by SP loading. Sodium phosphate loading significantly improved mean power output and 16.1 km time-trial performance of trained cyclists under laboratory conditions with functional increases in oxygen uptake.     

Strength training improves cycling performance,fractional utilization of VO2max and cycling economy in female cyclists

The purpose of this study was to investigate the effect of adding heavy strength training to well‐trained female cyclists’ normal endurance training on cycling performance. Nineteen female cyclists were randomly assigned to 11 weeks of either normal endurance training combined with heavy strength training (E+S, n = 11) or to normal endurance training only (E, n = 8). E+S increased one repetition maximum in one‐legged leg press and quadriceps muscle cross‐sectional area (CSA) more than E (P < 0.05), and improved mean power output in a 40‐min all‐out trial, fractional utilization of VO_2max and cycling economy (P < 0.05). The proportion of type IIAX‐IIX muscle fibers in m. vastus lateralis was reduced in E+S with a concomitant increase in type IIA fibers (P < 0.05). No changes occurred in E. The individual changes in performance during the 40‐min all‐out trial was correlated with both change in IIAX‐IIX fiber proportion (r = ?0.63) and change in muscle CSA (r = 0.73). In conclusion, adding heavy strength training improved cycling performance, increased fractional utilization of VO_2max, and improved cycling economy. The main mechanisms behind these improvements seemed to be increased quadriceps muscle CSA and fiber type shifts from type IIAX‐IIX toward type IIA.     

The ventilatory threshold, heart rate, and endurance performance: relationships in elite cyclists

The purpose of this study was to investigate the validity of the ventilatory response during incremental exercise as indication of endurance performance during prolonged high-intensity exercise under field test conditions in elite cyclists. The ventilatory threshold (VT) was assessed in 14 male elite cyclists (age 22.4+/-3.4 years, height 181+/-6 cm, weight 69.2+/-6.8 kg, VO2max 69+/-7 ml x min(-1) x kg(-1)) during an incremental exercise test (20 W x min(-1)). Heart rate and oxygen uptake were assessed at the following ventilatory parameters: 1. Steeper increase of VCO2 as compared to VO2 (V-slope-method); 2. Respiratory exchange ratio (RQ)=0.95 and 1.00; 3. VE/VO2 increase without a concomitant VE/VCO2 (VE/VO2 method). Three weeks following the laboratory tests, the ability to maintain high-intensity exercise was determined during a 40 km time trial on a bicycle. During this time trial the mean heart rate (HR(TT)) and the road racing time (TT) were assessed. The V-slope-method and the VE/VO2 method showed significant correlations with TT (V-slope: r = -0.82; p<0.001; 90% interval of confidence = +/-82 sec; VE/VO2: r=-0.81; p<0.01; 90% interval of confidence = +/-81 sec). Heart rate at the ventilatory parameters and at the maximum heart rate (HRmax) showed significant correlations with HR(TT). The V-slope-method is the preferred method to predict heart rate during prolonged high-intensity exercise (r=0.93; p<0.0001; 90% interval of confidence: +/-4.8 beats x min(-1)). For predicting heart rate during prolonged high-intensity exercise using an incremental exercise test (20 W x min(-1)), without the knowledge of ventilatory parameters, we recommend using the regression formula: H(TT)=0.84 x Hmax + 14.3 beats x min(-1) (r=0.85; p<0.001).     

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.     

Frequency of the VO2max plateau phenomenon in world-class cyclists

We aimed to determine the frequency of the VO2max plateau phenomenon in top-level male professional road cyclists (n = 38; VO2max [mean +/- SD]: 73.5 +/- 5.5 ml.kg(-1).min(-1)) and in healthy, sedentary male controls (n = 37; VO2max: 42.7 +/- 5.6 ml.kg(-1).min(-1)). All subjects performed a continuous incremental cycle-ergometer test of 1-min workloads until exhaustion. Power output was increased from a starting value of 25 W (cyclists) or 20 W (controls) at the rate of 25 W.min(-1) (cyclists) or 20 W.min(-1) (controls) until volitional exhaustion. We measured gas-exchange and heart rate (HR) throughout the test. Blood concentrations of lactate (BLa) were measured at end-exercise in both groups. We defined maximal exercise exertion as the attainment of a respiratory exchange rate (RER) >or= 1.1; HR > 95 % age-predicted maximum; and BLa > 8 mmo.l(-1). The VO2max plateau phenomenon was defined as an increase in two or more consecutive 1-min mean VO2 values of less than 1.5 ml.kg(-1).min(-1). Most cyclists met our criteria for maximal exercise effort (RER > 1.1, 100 %; 95 % predicted maximal HR [HRmax], 82 %; BLa > 8 mmol.l(-1), 84 %). However, the proportion of cyclists attaining a V.O (2max) plateau was considerably lower, i.e., 47 %. The majority of controls met the criteria for maximal exercise effort (RER > 1.1, 100 %; predicted HRmax, 68 %; BLa > 8 mmol. l(-1), 73 %), but the proportion of these subjects with a VO2max plateau was only 24 % (significantly lower proportion than in cyclists [p < 0.05]). Scientists should consider 1) if typical criteria of attainment of maximal effort are sufficiently stringent, especially in elite endurance athletes; and 2) whether those humans exhibiting the VO2max plateau phenomenon are those who perform an absolute maximum effort or there are additional distinctive features associated with this phenomenon.     

Inverse relationship between VO2max and economy/efficiency in world-class cyclists

PURPOSE: To determine the relationship that exists between VO2max and cycling economy/efficiency during intense, submaximal exercise in world-class road professional cyclists. METHODS Each of 11 male cyclists (26+/-1 yr (mean +/- SEM); VO2max: 72.0 +/- 1.8 mL x kg(-1) x min(-1)) performed: 1) a ramp test for O2max determination and 2) a constant-load test of 20-min duration at the power output eliciting 80% of subjects' VO2max during the previous ramp test (mean power output of 385 +/- 7 W). Cycling economy (CE) and gross mechanical efficiency (GE) were calculated during the constant-load tests. RESULTS: CE and GE averaged 85.2 +/- 2.3 W x L(-1) x min(-1) and 24.5 +/- 0.7%, respectively. An inverse, significant correlation was found between 1) VO2max (mL x kg(-0.32) x min(-1)) and both CE (r = -0.71; P = 0.01) and GE (-0.72; P = 0.01), and 2) VO2max (mL x kg(-1) x min(-1)) and both CE (r = -0.65; P = 0.03) and GE (-0.64; P = 0.03). CONCLUSIONS: A high CE/GE seems to compensate for a relatively low VO2max in professional cyclists.     

Acute effects of kinesio taping on a 6 s maximal cycling sprint performance

Based on the hypothesis that tactile stimulation affects muscle activation levels, we theorized that taping vastus medialis and vastus lateralis muscles would improve a 6 s sprint cycling performance. Thus, the aim of this study was to determine whether the use of kinesio taping (KT) was helpful in increasing maximal-intensity cycling exercise. Sixteen active healthy subjects were enrolled in a randomized placebo, repeated measures design. All subjects were tested on a cycle ergometer under three conditions: without taping, taping along anterior thigh muscles and sham taping across the same muscle groups. Results showed a significant increase in peak power output and total work after the application compared to the condition with no tape applied (p < 0.05). No significant difference was found between the two modes of application. Our findings indicated that the tactile stimulation of KT applied longitudinally provided positive effects during a sprint cycling performance in healthy and active subjects.     

Muscle deoxygenation and neural drive to the muscle during repeated sprint cycling

PURPOSE: To investigate muscle deoxygenation and neural drive-related changes during repeated cycling sprints in a fatiguing context. METHODS: Nine healthy male subjects performed a repeated-sprint test (consisting of 10 x 6-s maximal sprints interspaced by 30 s of recovery). Oxygen uptake was measured breath-by-breath; muscle deoxygenation of the vastus lateralis was assessed continuously using the near-infrared spectroscopy technique. Surface electromyograms (RMS) of both vastus lateralis and biceps femoris were also recorded. Furthermore, before and after the repeated-sprint test, the percentage of muscle activation by voluntary drive (twitch-interpolated method) was measured during a maximal voluntary contraction. RESULTS AND DISCUSSION: Consistent with previous research, our data showed a significant power decrement during repeated-sprint exercise. There was also a progressive muscle deoxygenation, but our data showed that the ability of the subjects to use available O2 throughout the entire repeated-sprint test was well preserved. Our data displayed a significant decrement in the RMS activity during the acceleration phase of each sprint across the repeated-sprint exercise. Moreover, decrement in motor drive was confirmed after exercise by a significant decrease in both percentage of voluntary activation and RMS/M-wave ratio during a maximal voluntary contraction. CONCLUSION: In this experimental design, our findings suggest that the ability to repeat short-duration (6 s) sprints was associated with the occurrence of both peripheral and central fatigue.