Purpose: This study aimed to determine how exercise intensity influences the amount of work required to induce changes in cyclists’ acute durability and to evaluate the suitability of using kilojoules (kJ) as a metric for fatigue monitoring. Methods: A systematic review was conducted following PRISMA guidelines. Web of Science, Medline, and Scopus were searched for studies assessing the relationship or effect between prior accumulated work and performance reductions in cyclists. Inclusion criteria required studies to measure power output after fatigue induced within a single session, with prior work quantified in kJ or other training load metrics. Results: Twenty-one studies were included in the systematic review. The primary finding was that high-intensity efforts (e.g., above critical power) led to greater power output reductions with lower accumulated work compared to low-to-moderate intensity efforts. Across studies, power output declines of 10–20% were observed after 2.5–15 kJ kg⁻ ¹ of prior high-intensity work, whereas similar or greater work volumes at lower intensities resulted in smaller performance decrements. While kJ was the most commonly used fatigue metric, it does not account for intensity, limiting its accuracy in durability assessments. Conclusions: Exercise intensity plays a crucial role in determining durability-related performance declines. The exclusive use of kJ as a fatigue metric may be insufficient, and alternative approaches incorporating intensity are needed. These findings have implications for training prescription and race strategies, emphasizing the need for intensity-specific workload quantification. Registration: OSF project no.: osf.io/kcg53.

Background/Objectives: This study aimed to evaluate the effects of four weeks of combined Acetyl-l-Carnitine and alpha-lipoic acid (ALA) supplementation on anaerobic and aerobic performance and fatigue resistance in trained cyclists, hypothesizing improvements in maximal aerobic power (MAP), Wingate test performance, and reduced lactate accumulation. Methods: In a double-blind, randomized trial, 41 male trained cyclists (age: 36 ± 12 years; MAP: 4.35 ± 0.60 W·kg⁻¹) were assigned to a supplement group (SUP, n = 19; 1200 mg/day Acetyl-l-Carnitine, 300 mg/day ALA, 1.1 mg Vitamin B1, 2.5 µg Vitamin B12) or placebo group (PLA, n = 22) for four weeks. Performance was assessed pre- and post-intervention via counter-movement jumps (CMJs), Wingate tests (WG₁, WG₂), and a graded exercise test (GXT). Blood lactate ([La⁻]) was measured post-Wingate. A three-way mixed ANOVA analyzed Wingate performance (session, order, and group), and a two-way ANOVA assessed MAP and fatigue effects. Results: MAP increased by 3.4% (314 ± 32 W to 324 ± 37 W; p = 0.005) with no group interaction (p = 0.457). Wingate peak power showed main effects for order (p < 0.001) and session (p = 0.011) but no group interaction (p = 0.676). SUP reduced [La⁻] by 1.5 mmol·L⁻¹ post-WG₂ in POST (p = 0.049). No significant group differences were found for CMJ or fatigue metrics. Conclusions: Four weeks of Acetyl-l-Carnitine and ALA supplementation did not enhance aerobic or anaerobic performance in trained cyclists, despite reducing blood lactate after high-intensity exercise, suggesting no ergogenic benefits.

This study evaluated the influence of cycle computers on the accuracy of power and cadence data. The research was divided into three phases: (1) a graded exercise test (GXT) at different constant loads to record power and cadence data; (2) a self-paced effort lasting 1 min to measure mean maximal power output (MMP); and (3) a short all-out effort. Eight cyclists completed the GXT, ten participated in the 1-min test, and thirty participated in the sprint effort. All participants pedaled on a controlled-resistance cycle ergometer, and the data were recorded using the ergometer itself and ten synchronized cycle computers of the same brand, configured to record at 1 Hz. The results showed minimal variations in power and cadence between devices during the GXT, suggesting adequate accuracy for constant efforts lasting a certain duration. However, in self-paced and high-intensity efforts (1-min and short all-out efforts), significant differences were observed between several devices, particularly in cadence and mean power, highlighting the relevance of device selection in these contexts. These findings suggest that, while variations in constant efforts may be negligible, in short-duration, high-intensity activities, the choice of device may be crucial for the accuracy and reliability of the data.

Task failure in endurance sports represents a complex and multifaceted phenomenon likely arising from the dynamic and intricate interaction between peripheral and central mechanisms. Traditional models of fatigue have long emphasized a gradual and inevitable decline in performance because of metabolic, neuromuscular, and cardiovascular limitations. Research has also highlighted that task failure may not only be a product of this progressive deterioration but could also result from acute and unpredictable disruptions at the central level (e.g., psychological factors such as perceived effort) that compromise the athlete’s ability to sustain effort. This review examines the existing literature on task failure, critically describing what is currently known about the influence of peripheral (physiological processes at the skeletal muscle and neuromuscular junction) and central mechanisms (neural processes in the brain and spinal cord, which may integrate physiological and psychological components). Finally, we identify gaps in the current literature and propose directions for future research to refine our understanding of the interplay between peripheral and central contributors to task failure, emphasizing the need for integrative approaches to optimize endurance performance.

Objectives: The present study aimed to examine the relationships between screen time (ST), sleep time (SLT), physical activity engagement (PA), Mediterranean diet (MD) adherence, body mass index (BMI), self-esteem (SE) and academic performance (AP) in high-socioeconomic-status (SES) school-aged youth in southern Spain. Methods: A descriptive, comparative, non-experimental and cross-sectional research study was conducted with a total sample of 217 Spanish students (13.88 ± 1.32). Structural equation modelling (SEM) was employed to analyse relationships between study variables as a function of sex. Results: SLT was positively associated with MD adherence and negatively related with BMI. Both PA and MD adherence were positively linked to SE, whilst MD adherence and SE were also positively related to AP. Regarding sex differences, ST was a stronger determinant among girls, showing negative associations with PA (β = −0.378; p < 0.001) and MD adherence (β = −0.315; p < 0.001), with this pattern not being observed in boys. PA was positively associated with SE in both sexes, but more strongly in boys (β = 0.332; p < 0.001) than in girls (β = 0.190; p = 0.034). In girls, both MD adherence (β = 0.295; p < 0.001) and SE (β = 0.224; p = 0.008) were positively associated with AP, with these associations not being found in boys. Conclusions: The findings underscore the complex interplay between lifestyle behaviours, psychosocial factors, and AP in school-aged youth. Regardless of SES, interventions should focus on reducing ST, promoting PA and MD adherence, and enhancing SE whilst considering sex-specific patterns.

This pre-registered study tested whether power meter data availability affects perceived voluntariness and performance in cyclists accustomed to power meters. Forty highly trained cyclists completed two counterbalanced maximal incremental tests: one without feedback (control) and one with real-time power visualization. Confirmatory analyses showed that power visualization increased maximal aerobic power (MAP; p = 0.004, Cohen’s d = 0.487) without affecting maximal oxygen uptake (VO _2MAX ; p = 0.269), maximal heart rate ( p = 0.383), rating of perceived exertion (RPE; p = 0.141), or perceived voluntariness ( p = 0.159). Exploratory analyses revealed an order effect ( p = 0.021, η p 2 = 0.133): participants who first performed the test with power data perceived their decision to stop as more voluntary in that condition compared to the subsequent control test. This effect was absent in the reverse order group ( p = 0.749). No order effects were found for other variables. Cyclists’ performance judgments aligned with actual MAP differences between conditions. Overall, these findings show that access to power data enhances MAP. Although the main analysis pointed to a null effect on perceived voluntariness of the decision to stop, an exploratory order effect suggested that removing power data after prior exposure reduces perceived control over task failure decisions, warranting further investigation. This study highlights the role of performance feedback in shaping objective and subjective performance in cycling.