An improved methodology for estimating critical power from mean maximal power output data.

The aim of this study was to determine if Critical Power (CP) and W' can be estimated from mean maximal power output (MMP) data collected in cycling races. Data were collected from 13 under 23 professional cyclists (mean ± SD; age, 19.5 ± 1.1 y; body mass, 66.3 ± 5.0 kg; height, 180.0 ± 5.0 cm; CP, 5.7 ± 0.3 W · kg-1). Participants conducted a CP test in the field to determine CPTest and W'Test. MMP data were then collected in races for the subsequent 90 days. CP and W' were estimated from MMP values in two ways, using fixed MMP durations, 2, 5 and 12 min (CPFixed and W'Fixed), and via a novel filtering of second-by-second MMP data (CPFiltered and W'Filtered). CPFixed and CPFiltered were not significantly different from CPTest (Mean Difference (MD) 5 W and 7 W, respectively, p > 0.05). W'Fixed and W'Filtered were not significantly different from W'Test (MD 2.68 kJ and 0.89 kJ, respectively, p > 0.05). CPFixed and CPFiltered correlated significantly with CPTest (r = 0.872 and 0.922, respectively, p < 0.0001 for both). Neither W'Fixed nor W'Filtered correlated significantly with W'Test (p > 0.05). Both CPFixed and CPFiltered provide valid estimates of CPTest.; however, CPFiltered provides a better estimate.

Alterations in aerobic fitness and muscle deoxygenation during ramp incremental exercise in trained youth cyclists: a ~3-year longitudinal study.

Alterations of aerobic fitness and muscle deoxygenation during a ramp incremental exercise test (GXT) were assessed on two occasions within a time-frame of 2.9 ± 0.1y in competitive youth cyclists. Nine cyclists (age, 14.5 ± 1.1y; peak oxygen uptake (V˙O2peak), 62.6 ± 4.2 mL.min-1.kg-1) participated in this investigation. V˙O2peak, the gas exchange threshold (GET) and the respiratory compensation point (RCP), as well as the muscle deoxygenation response pattern were determined during a GXT using open circuit spirometry and near-infrared spectroscopy, respectively. T-tests and Pearson's correlations were used to assess effects of time on the dependent variables and relationships between changes of parameter estimates of aerobic fitness and the muscle deoxygenation response, respectively. Workrate and metabolic rate at GET (33 ± 20 and 42 ± 23%) and RCP (36 ± 20 and 40 ± 22%), and V˙O2peak (30 ± 18%) significantly increased throughout the study (P < 0.05). The muscle deoxygenation response showed a significant rightward shift from occasion one to two (P < 0.05). Alterations in the workrate/metabolic rate at RCP, and V˙O2peak, were correlated with alterations of the muscle deoxygenation response (R = 0.71-0.89, P < 0.05). Together, this is thought to indicate a superior muscle perfusion within the tissue of interrogation at the same metabolic rate on occasion two vs. one, which partially contributed to the improved aerobic fitness in the cyclists herein.

Power profiling and the power-duration relationship in cycling: a narrative review.

Emerging trends in technological innovations, data analysis and practical applications have facilitated the measurement of cycling power output in the field, leading to improvements in training prescription, performance testing and race analysis. This review aimed to critically reflect on power profiling strategies in association with the power-duration relationship in cycling, to provide an updated view for applied researchers and practitioners. The authors elaborate on measuring power output followed by an outline of the methodological approaches to power profiling. Moreover, the deriving a power-duration relationship section presents existing concepts of power-duration models alongside exercise intensity domains. Combining laboratory and field testing discusses how traditional laboratory and field testing can be combined to inform and individualize the power profiling approach. Deriving the parameters of power-duration modelling suggests how these measures can be obtained from laboratory and field testing, including criteria for ensuring a high ecological validity (e.g. rider specialization, race demands). It is recommended that field testing should always be conducted in accordance with pre-established guidelines from the existing literature (e.g. set number of prediction trials, inter-trial recovery, road gradient and data analysis). It is also recommended to avoid single effort prediction trials, such as functional threshold power. Power-duration parameter estimates can be derived from the 2 parameter linear or non-linear critical power model: P(t) = W'/t + CP (W'-work capacity above CP; t-time). Structured field testing should be included to obtain an accurate fingerprint of a cyclist's power profile.

Effects of Flat and Uphill Cycling on the Power-duration Relationship.

The purpose of this study was to investigate the effects of flat and uphill cycling on critical power and the work available above critical power. Thirteen well-trained endurance athletes performed three prediction trials of 10-, 4- and 1-min in both flat (0.6%) and uphill (9.8%) cycling conditions on two separate days. Critical power and the work available above critical power were estimated using various mathematical models. The best individual fit was used for further statistical analyses. Paired t-tests and Bland-Altman plots with 95% limits of agreement were applied to compare power output and parameter estimates between cycling conditions. Power output during the 10- and 4-min prediction trial and power output at critical power were not significantly affected by test conditions (all at p>0.05), but the limits of agreement between flat and uphill cycling power output and critical power estimates are too large to consider both conditions as equivalent. However, power output during the 1-min prediction trial and the work available above critical power were significantly higher during uphill compared to flat cycling (p<0.05). The results of this investigation indicate that gradient affects cycling time-trial performance, power output at critical power, and the amount of work available above critical power.

Climbing Performance in U23 and Professional Cyclists during a Multi-stage Race.

The aim of this study was to analyze climbing performance across two editions of a professional multistage race, and assess the influence of climb category, prior workload, and intensity measures on climbing performance in U23 and professional cyclists. Nine U23 cyclists (age 20.8±0.9 years) and 8 professional cyclists (28.1±3.2 years) participated in this study. Data were divided into four types: overall race performance, climb category, climbing performance metrics (power output, ascent velocity, speed), and workload and intensity measures. Differences in performance metrics and workload and intensity measures between groups were investigated. Power output, ascent velocity, speed were higher in professionals than U23 cyclists for Cat 1 and Cat 2 (p≤0.001-0.016). Workload and intensity measures (Worktotal, Worktotal∙km-1, Elevationgain, eTRIMP and eTRIMP∙km-1) were higher in U23 compared to professionals (p=0.002-0.014). Climbing performance metrics were significantly predicted by prior workload and intensity measures for Cat 1 and 2 (R2=0.27-0.89, p≤0.001-0.030) but not Cat 3. These findings reveal that climbing performance in professional road cycling is influenced by climb categorization as well as prior workload and intensity measures. Combined, these findings suggest that Cat 1 and 2 climbing performance could be predicted from workload and intensity measures.

Differences in Training Characteristics Between Junior, Under 23 and Professional Cyclists.

The aim was to compare the training characteristics of junior, under 23 and professional road cyclists. Training data collected during the 2019 competitive season of thirty male cyclists, divided into three age-related categories (JUN; U23; PRO), were retrospectively analyzed for training characteristics, external and internal training load. Higher duration per training session were observed in PRO (2.6±0.3 h) compared to both U23 (2.2±0.3 h; P<0.001) and JUN (2.0±0.2 h; P<0.001). Elevation gain per distance was higher in PRO (13.8±1.9 m·km-1) compared to U23 (10.6±0.9 m·km-1; P=0.001) and JUN (6.7±0.3 m·km-1; P<0.001), and in U23 compared to JUN (P<0.001). Annual total work was lower in JUN (3694±467 kJ·kg-1) compared to U23 (5268±746 kJ·kg-1; P=0.001) and PRO (5759±1103 kJ·kg-1; P<0.001). eTRIMP per hour was higher in JUN (151±40) compared to both U23 (115±23; P=0.003) and PRO (112±22; P=0.013). JUN spent more training time at medium and high heart rate intensity zones compared to U23 and PRO (P<0.05).

Elite versus non-elite cyclist - Stepping up to the international/elite ranks from U23 cycling.

This study investigated the physiological, performance and training characteristics of U23 cyclists and assessed the requirements of stepping up to the elite/international ranks. Twenty highly trained U23 cyclists (age, 22.1 ± 0.8 years; body mass, 69.1 ± 6.8 kg; VO2max, 76.1 ± 3.9 ml·kg-1·min-1) participated in this study. The cyclists were a posteriori divided into two groups based on whether or not they stepped up to elite/international level cycling (U23ELITE vs. U23NON-ELITE). Physiological, performance and training and racing characteristics were determined and compared between groups. U23ELITE demonstrated higher absolute peak power output (p = .016), 2 min (p = .026) 5 min (p = .042) and 12 min (p ≤ .001) power output as well as higher absolute critical power (p = .002). Further, U23ELITE recorded more accumulated hours (p ≤ .001), covered distance (p ≤ .001), climbing metres (p ≤ .001), total sessions (p ≤ .001), total work (p ≤ .001) and scored more UCI points (p ≤ .001). These findings indicate that U23ELITE substantially differed from U23NON-ELITE regarding physiological, performance and training and racing characteristics derived from laboratory and field. These variables should be considered by practitioners supporting young cyclists throughout their development towards the elite/international ranks.

Non-sustained microvolt level T-wave alternans in congenital long QT syndrome types 1 and 2.

BACKGROUND: Patients with long QT syndrome (LQTS) are predisposed to polymorphic ventricular tachycardia (VT) during adrenergic stimulation. Microvolt T-wave alternans (MTWA) is linked to vulnerability to VT in structural heart disease. The prevalence of non-sustained MTWA (NS-MTWA) in LQTS is unknown. METHODS: 31 LQT1, 42 LQT2, and 80 controls underwent MTWA testing during exercise. MTWA tests were classified per standardized criteria, and re-analyzed according to the modified criteria to account for NS-MTWA. RESULTS: LQT1 and LQT2 patients had a significantly higher frequency of late NS-MTWA (26% and 12%) compared to controls (0%). There was no significant difference between the groups with respect to sustained and early NS-MTWA. Late NS-MTWA was significantly associated with QTc. CONCLUSION: LQT1 and LQT2 patients had a higher prevalence of late NS-MTWA during exercise than matched controls. NS-MTWA likely reflects transient adrenergically mediated dispersion of repolarization, and could be a marker of arrhythmic risk in LQTS.

Microvolt T-wave alternans amplifies spatial dispersion of repolarization in human subjects with ischemic cardiomyopathy.

INTRODUCTION: In experimental models, spatial dispersion of repolarization (DOR) due to discordant cellular alternans predisposes to ventricular fibrillation. To test the hypothesis that microvolt T-wave alternans (MTWA) in humans causes spatial DOR, we measured Tpeak-Tend interval (Tpe) and Tpe/QT ratio, electrocardiographic indices of spatial DOR. METHODS: Mean Tpe and Tpe/QT were compared in ischemic cardiomyopathy patients with positive and negative MTWA studies. RESULTS: MTWA was positive in 12 and negative in 24 patients. Tpe and Tpe/QT were higher in MTWA+ subjects compared to MTWA- subjects during exercise (64.5±6.8 vs. 54.9±8.7ms, p=0.001 and 0.218±0.03 vs. 0.177±0.02, p=0.001) but not at rest. CONCLUSION: Ischemic cardiomyopathy patients have increased Tpe and Tpe/QT when MTWA is induced during exercise, suggesting that MTWA causes increased spatial DOR in humans. Future studies are needed to determine if Tpe and Tpe/QT during exercise might predict increased risk of SCD alone or in combination with measurement of MTWA.

Does manual T-wave window adjustment affect microvolt T-wave alternans results in patients with structural heart disease?

INTRODUCTION: Microvolt T-wave alternans (MTWA) analysis can identify patients at low risk of sudden cardiac death who might not benefit from an implantable cardioverter-defibrillator (ICD). Current spectral methodology for performing MTWA analysis may "miss" part of the T-wave in patients with QT prolongation. The value of T-wave window adjustment in patients with structural heart disease has not been studied. METHODS: We assembled MTWA data from 5 prior prospective studies including 170 patients with reduced left ventricular ejection fraction, adjusted the T-wave window to include the entire T-wave, and reanalyzed MTWA. RESULTS: Of 170 patients, 43% required T-wave window adjustment. Only 3 of 170 patients (1.8%) had a clinically significant change in MTWA results. CONCLUSIONS: In 98.2% of patients, T-wave window adjustment did not improve the accuracy of MTWA analysis. Spectral MTWA as currently implemented remains effective for identifying patients with structural heart disease unlikely to benefit from ICD therapy.

In Situ Power-Cadence Relationship for 2-, 5-, and 20-Minute Duration: A Proof of Concept in Under-19 Cyclists.

BACKGROUND: The force-velocity relationship suggests that maximal power (Pmax) can only be produced in optimal torque (Topt) and cadence (Copt). However, the cadence at which mean maximal power (MMP) is produced has never been studied. This study aimed to determine the individual MMP-cadence relationship from in situ data. METHOD: We analyzed 1 year of data from 14 under-19 cyclists and calculated the MMP for each cadence between 50 and 120 rpm for 2-, 5-, and 20-minute durations. The MMP-cadence relationship was fit with a second-order polynomial function. The goodness of fit (r2) and odd-day-even-day absolute and relative reliability were evaluated, respectively, for Pmax, Topt, and Copt. RESULTS: The goodness of fit was very high for every duration studied. Topt and Pmax, but not Copt, were significantly higher for shorter durations. Pmax was significantly correlated only with Topt for the 3 durations (r2 = .63, .71, and .64 for 2, 5, and 20 min, respectively). DISCUSSION: Evaluation of the MMP-cadence relationship from in situ data is feasible and reliable for 2-, 5-, and 20-minute durations. This profiling approach would enable better detection of the strengths and weaknesses of cyclists and make it possible to design more effective training interventions. PRACTICAL APPLICATIONS: The analysis makes it possible to identify the torque versus cadence component that individually limits power production. Knowing the Copt for a given duration of maximal effort could help athletes choose the right gear ratio and regulate cadence during a race in order to maximize performance.

Is all work the same? Performance after accumulated work of differing intensities in male professional cyclists.

OBJECTIVES: Although the ability to attenuate power output (PO) declines after accumulated work (i.e., 'durability') is increasingly recognized as a major determinant of cycling performance, the potential role of the intensity of the previous work is unclear. We assessed the effect of work-matched levels of accumulated work at different intensities on performance in male professional cyclists. DESIGN: Observational field-based study. METHODS: PO data was registered in 17 cyclists during a competition season, and the critical power (CP) was repeatedly determined every 4 weeks from training sessions and competitions. Participants' maximum mean power (MMP) for different durations (5 s, 5 min, 10 min, and 20 min) and the CP were determined under 'fresh' conditions (0 kJ·kg-1) and after varying levels of accumulated work (2.5, 5.0 and 7.5 kJ·kg-1) at intensities below and above the CP. RESULTS: A significant decline was found for all MMP values following all levels of accumulated work above the CP (-4.0 %, -1.7 %, -1.8 %, and -3.2 % for 30s, 5 min, 10 min and 20 min-MMP, respectively; all p < 0.001), versus no change after any level of accumulated work below the CP (all p > 0.05). Similar results were observed for the CP, which decreased after all levels of accumulated work above (-2.2 %, -6.1 %, and -16.2 %, after 2.5, 5.0 and 7.5 kJ·kg-1, p < 0.001) but not below this indicator (p > 0.05). CONCLUSIONS: In male professional cyclists, accumulated work above the CP impairs performance compared with work-matched, albeit less intense efforts. This raises concerns on the use of mechanical work per se as a single fatigue/stress indicator in these athletes.

The Influence of High-Intensity Work on the Record Power Profile of Under-23, Pro Team, and World Tour Cyclists.

BACKGROUND: Durability (ie, the ability to attenuate the decline in performance after accumulated work) has been identified as a performance determinant in elite cyclists. The aim of the present study was to compare durability in elite cyclists of various performance levels, particularly after high-intensity work, referred to as "high-intensity durability." METHODS: Forty-nine (N = 49) male road cyclists were categorized as either under 23 years of age (U23) (N = 11), Pro Team (N = 13), or World Tour (N = 24). The participants' critical power (CP) was assessed during the preseason. Thereafter, the participants' maximum mean power (MMP) values were determined for efforts of different durations (from 5 s to 30 min) after different levels of accumulated work above CP (from 0 to 7.5 kJ·kg-1). RESULTS: U23 cyclists showed a significant reduction of all relative MMP values for durations ≥1 minute after ≥5 kJ·kg-1 above CP compared with the "fresh" state (0 kJ·kg-1), whereas in Pro Team and World Tour cyclists, a significant reduction was not observed until 7.5 kJ·kg-1 above CP. In the "fresh" state, both Pro Team and particularly World Tour cyclists attained higher MMP values for efforts ≥10 minutes than U23 riders. However, more differences emerged with greater previous work levels, and indeed after 7.5 kJ·kg-1 above CP World Tour cyclists attained higher MMP values than both U23 and Pro Team cyclists for most efforts (≥30 s). CONCLUSION: Pro Team and particularly World Tour cyclists tolerate greater levels of accumulated work at high intensity, which might support the importance of high-intensity durability for performance.

The role of pre-treatment white matter abnormalities in developing white matter changes following whole brain radiation: a volumetric study.

White matter injury is a known complication of whole brain radiation (WBRT). Little is known about the factors that predispose a patient to such injury. The current study used MR volumetrics to examine risk factors, in particular the influence of pre-treatment white matter health, in developing white matter change (WMC) following WBRT. Thirty-four patients with unilateral metastatic disease underwent FLAIR MRI pre-treatment and at several time points following treatment. The volume of abnormal FLAIR signal in the white matter was measured in the hemisphere contralateral to the diseased hemisphere at each time point. Analyses were restricted to the uninvolved hemisphere to allow for the measurement of WBRT effects without the potential confounding effects of the disease on imaging findings. The relationship between select pre-treatment clinical variables and the degree of WMC following treatment was examined using correlational and regression based analyses. Age when treated and volume of abnormal FLAIR prior to treatment were significantly associated with WMC following WBRT; however, pre-treatment FLAIR volume was the strongest predictor of post-treatment WMCs. Age did not add any predictive value once white matter status was considered. No significant relationships were found between biological equivalent dose and select cerebrovascular risk factors (total glucose, blood pressure, BMI) and development of WMCs. The findings from this study identify pre-treatment white matter health as an important risk factor in developing WMC following WBRT. This information can be used to make more informed decisions and counsel patients on their risk for treatment effects.

Acute and subacute changes in neural activation during the recovery from sport-related concussion.

To study the natural recovery from sports concussion, 12 concussed high school football athletes and 12 matched uninjured teammates were evaluated with symptom rating scales, tests of postural balance and cognition, and an event-related fMRI study during performance of a load-dependent working memory task at 13 h and 7 weeks following injury. Injured athletes showed the expected postconcussive symptoms and cognitive decline with decreased reaction time (RT) and increased RT variability on a working memory task during the acute period and an apparent full recovery 7 weeks later. Brain activation patterns showed decreased activation of right hemisphere attentional networks in injured athletes relative to controls during the acute period with a reversed pattern of activation (injured > controls) in the same networks at 7 weeks following injury. These changes coincided with a decrease in self-reported postconcussive symptoms and improved cognitive test performance in the injured athletes. Results from this exploratory study suggest that decreased activation of right hemisphere attentional networks mediate the cognitive changes and postconcussion symptoms observed during the acute period following concussion. Conversely, improvement in cognitive functioning and postconcussive symptoms during the subacute period may be mediated by compensatory increases in activation of this same attentional network.

The relationship between training characteristics and durability in professional cyclists across a competitive season.

This study investigated the influence of training characteristics on the fatigued power profile in professional cyclists. Data was collected from 30 under 23 professional cyclists (age: 20.1 ± 1.1 years, body mass: 69 ± 6.9 kg, height: 182.6 ± 6.2 cm, V˙O2max: 73.8 ± 2.5 mL·kg-1·min-1, CP: 5.48 ± 0.38 W·kg-1, W´: 17.83 ± 3.57 kJ) across a competitive season and collated in to 3 periods: early-, mid- and late-season. Two power profiles (fresh and fatigued) were created from absolute (W) and relative (W·kg-1) 2-, 5-, and 12-min maximal mean power outputs. The fresh power profile consisted exclusively of power output values produced prior to 2000 kJ work (2MMPfresh, 5MMPfresh and 12MMPfresh) while the fatigued power profile consisted of power output values produced exclusively post 2000 kJ (2MMPfatigue 5MMPfatigue and 12MMPfatigue). Training characteristics were analysed to assess their influence on the power profiles. Absolute 5MMPfatigue, 12MMPfatigue and relative 12MMPfatigue were significantly lower in late-season compared with early- and mid-season (p < 0.05). The difference in absolute 12MMPfresh and 12MMPfatigue was significantly greater in late than in early- and mid-season. A significant relationship was found between training time below the first ventilatory threshold (Time < VT1) and improvements in absolute and relative 2MMPfatigue (r = 0.43 p = 0.018 and r = 0.376 p = 0.04 respectively); and between a shift towards a polarized training intensity distribution and improvements in absolute and relative 12MMPfatigue (r = 0.414 p = 0.023 for both) between subsequent periods. In conclusion, there is greater variability in the fatigue power profile across a competitive season than the fresh power profile.HighlightsThe fatigued power profile varies throughout a competitive seasonThe difference between the fresh and fatigued power profiles is not fixed across a competitive seasonA tendency towards a polarized training intensity distribution is associated with an improvement in the fatigue power profile.

The Relationship between Physiological Characteristics and Durability in Male Professional Cyclists.

PURPOSE: This study aimed to determine if durability can be predicted from laboratory measures in a professional cycling population. METHODS: Data were collected from 10 professional cyclists (age = 19.2 ± 0.8 yr, body mass = 70.4 ± 5.5 kg, height = 182.9 ± 4.0 cm, body mass index = 21.0 ± 1.3 kg·m -2 , V̇O 2max = 74.4 ± 4.8 mL·kg -1 ·min -1 , critical power [CP] = 5.6 ± 0.6 W·kg -1 , W' = 23.7 ± 5.4 kJ). Participants completed a laboratory test and a CP test on two occasions. The second occasion was preceded by a novel fatiguing protocol, which consisted of five bouts of 8-min of exercise at 105%-110% of CP. CP in a fatigued state was expressed as a percentage of the fresh CP and coined delta CP (∆CP). The Pearson product correlation analysis was conducted to determine the relationship between laboratory-based measures and ∆CP. RESULTS: Significant positive relationships were found between ∆CP and relative peak power output ( r = 0.891, P < 0.001), relative maximum oxygen uptake ( r = 0.835, P = 0.003), relative power output at the second ventilatory threshold ( r = 0.738, P = 0.015), power output at the first ventilatory threshold ( r = 0.748, P = 0.013) and relative power output at the first ventilatory threshold ( r = 0.826, P = 0.003), gross efficiency at 300 W ( r = 0.869, P = 0.001), and at 200 W ( r = 0.792, P = 0.006). Significant negative relationships were found between ∆CP and carbohydrate oxidation at 200 W ( r = -0.702, P = 0.024). A multiple linear regression demonstrated that ∆CP can be predicted from laboratory measures ( R2 = 0.96-0.98, P < 0.001). CONCLUSIONS: These findings demonstrate the physiological determinants of durability in a professional cycling population.

Predictors of cycling performance success: Traditional approaches and a novel method to assess performance capacity in U23 road cyclists.

OBJECTIVES: This study aimed to investigate predictors of cycling performance in U23 cyclists by comparing traditional approaches to a novel method - the compound score. Thirty male U23 cyclists (N = 30, age 20.1 ±â€¯1.1 yrs, body mass 69.0 ±â€¯6.9 kg, height 182.6 ±â€¯6.2 cm, V̇O2max 73.8 ±â€¯2.5 mL·kg-1·min-1) participated in this study. DESIGN: Power output information was derived from laboratory and field-testing during pre-season and mean maximal power outputs (MMP) from racing season. Absolute and relative 5-min MMP, 5-min MMP after 2000 kJ (MMP2000 kJ), allometric scaling and the compound score were compared to the race score and podium (top 3) performance during a competitive season. METHODS: Positive and negative predictive values were calculated for all significant performance variables for the likelihood of a podium performance. RESULTS: The absolute 5-min MMP of the field test revealed the highest negative predictive capacity (82.4%, p = 0.012) for a podium performance. The compound score of the 5-min MMP2000 kJ demonstrated the highest positive and average predictive capacity (83.3%, 78.0%, p = 0.007 - respectively). The multi-linear regression analysis revealed a significant predictive capacity between performance variables and the race score (R2 = 0.55, p = 0.015). CONCLUSIONS: Collectively the results of the present study reveal that the compound score, alongside absolute power, was able to predict the highest positive and average likelihood for a podium performance. These findings can help to better understand performance capacity from field data to predict future cycling success.

Physiological Characteristics of Competitive Male Junior Cyclists Transitioning to the Under-23 Level: A Retrospective Comparative Study.

PURPOSE: The purpose of the current investigation was to retrospectively assess possible differences in physiological performance characteristics between junior cyclists signing a contract with an under-23 (U23) development team versus those failing to sign such a contract. METHODS: Twenty-five male junior cyclists (age: 18.1 [0.7] y, stature: 181.9 [6.0] cm, body mass: 69.1 [7.9] kg, peak oxygen uptake: 71.3 [6.2] mL·min-1·kg-1) were assigned to this investigation. Between September and October of the last year in the junior category, each cyclist performed a ramp incremental exercise test to determine certain physiological performance characteristics. Subsequently, participants were divided in 2 groups: (1) those signing a contract with a U23 development team (JUNIORU23) and (2) those failing to sign such a contract (JUNIORNON-U23). Unpaired t tests were used to assess possible between-groups differences in physiological performance characteristics. The level of statistical significance was set at P < .05 two tailed. RESULTS: No significant between-groups differences in submaximal (ie, gas exchange threshold, respiratory compensation point) and maximal physiological performance characteristics (ie, peak work rate, peak oxygen uptake) expressed in absolute values (ie, L·min-1, W) were observed (P > .05). However, significant between-groups differences were observed when physiological performance characteristics were expressed relative to the cyclists' body weights (P < .05). CONCLUSIONS: The current investigation showed that junior cyclists stepping up to a U23 development team might be retrospectively differentiated from junior cyclists not stepping up based on certain physiological performance characteristics, which might inform practitioners and/or federations working with young cyclists during the long-term athletic development process.