Training Load Research Articles

Training Load, Official Match Locomotor Demand, and Their Association in Top-Class Soccer Players During a Full Competitive Season.

Riboli, A, Nardi, F, Osti, M, Cefis, M, Tesoro, G, and Mazzoni, S. Training load, official match locomotor demand, and their association in top-class soccer players during a full competitive season. J Strength Cond Res 39(2): 249-259, 2025-To examine training load and official match locomotor demands of top-class soccer players during a full competitive season and to evaluate their association. Twenty-five top-class soccer players competing in UEFA international competitions were included. The season was divided into 2 different categories: 2 matches (M2) or 3 matches (M3) in 8 days. Starters and nonstarters were classified. Total distance (TD), high-speed running (HSR, 15-20 km·h-1), very high-speed running (VHSR, 20.1-24 km·h-1), sprint (SPR, >24.1 km·h-1), and accelerations/decelerations (Acc + Dec, >3 m·s2) were recorded. Trivial to moderate differences (p < 0.05) in training load between M2 and M3 were found: HSR, VHSR, and SPR were higher in M2 than M3, whereas TD and Acc + Dec were higher in M3 than M2. Week-by-week variability in training load ranged from ∼16 to ∼59% depending on metrics. Official match locomotor demands were similar (p > 0.05) in M2 and M3 with ∼5 to ∼29% match-to-match variability depending on metrics. Total load (i.e., training plus match loads) was higher (p < 0.05, ES: 0.75/1.61) in starters than nonstarters, because of a higher match load and no difference in the training load. Very high-speed running and SPR accumulated during training sessions were largely to very largely (r = 0.60 to 0.72) associated with TD, HSR, VHSR, and Acc + Dec covered during official match; VHSR and TD during training were largely to very largely (r = 0.57 and 0.71) associated with SPR and Acc + Dec during official match. In conclusion, (a) congested periods seemed to not affect official match locomotor performance; (b) practitioners may consider high week-by-week workload variability for individualizing training prescriptions, especially for nonstarters; and (c) the VHSR and SPR accumulated during training were associated with the official match locomotor demands, and it may be considered for maximizing performance.

An investigation into instantaneously tuning the EMI shielding characteristics of CNT-based nanocomposite biofoams in the X-band range by strain loading

The electromagnetic interference (EMI) shielding of CNT-based nanocomposite biofoams is capable of being tailored instantaneously by mechanical loading. In contrast to tuning the EMI shielding via nanofillers or by decoration process, the strain-activated EMI tailoring characteristics possess enormous potential that still await to be explored. To reveal this tailoring mechanism, a multi-scale electro-magneto-mechanically coupled homogenization model is developed to tailor the EMI characteristics of CNT-based nanocomposite biofoams in the X-band range (8.2–12.4 GHz). In this development, the elastic moduli, complex conductivity, and complex permeability are all selected as the homogenization variables. Four categories of interface effects are considered, including imperfect interface bonding, electron tunneling, Maxwell-Wagner-Sillars polarization, and electron hopping. The predicted EMI tailoring characteristics are validated by the experiment of CNT/wheat flour nanocomposite biofoam over a wide range of stain loading. The effective EMI shielding behavior decreases with the compressive loading, but it increases with the tensile loading. It is found that a CNT content higher than the percolation threshold is necessary to tailor the EMI shielding behavior of this nanocomposite foam via strain loading. This study can provide innovative insights to tune the EMI shielding characteristics of CNT-based nanocomposite biofoams in X-band instantaneously.

Effect of strain waveform modeling and loading frequency on the fatigue life of asphalt concrete

Effect of strain waveform modeling and loading frequency on the fatigue life of asphalt concrete

Dynamic Performance Assessment of MSE Walls under High-Speed Train Loads

Dynamic Performance Assessment of MSE Walls under High-Speed Train Loads

Warning Signs, Monitoring Tools, and Actions Taken by World-Class Endurance Coaches in Cases of Underperformance.

To describe warning signs, monitoring tools, and training- and non-training-related actions taken by world-class endurance coaches in cases of underperformance. Twelve highly acclaimed male Norwegian coaches known for coaching world-class endurance athletes with a remarkable collection of over 350 Olympic, World, and European Championship medals-primarily with Norwegian athletes-participated in the study. Data collection and analyses followed a 3-step pragmatic qualitative study design, including an initial questionnaire, in-depth interviews, and structured negotiation between researchers and coaches. Reduced performance levels and discrepancies between external (speed or power output) and internal (heart rate, lactate concentrations, and rating of perceived exertion) training-intensity measures in competitions, key training sessions, and testing scenarios, as well as observed changes in emotional state and coach-athlete communication, were highlighted as early warning signs of underperformance. Consistently, daily follow-up, systematic use of training diaries, training-intensity measures, and information from testing scenarios were rated as the most important monitoring tools in both detection and management of underperformance. In cases of underperformance, ruling out medical conditions as underlying causes was followed by a decreased training load (intensity and volume) and actions to reduce life stress to restore athletes' performance levels. The presented data collectively propose applying both objectively and subjectively measured monitoring tools and systems to the early detection and management of underperformance in endurance athletes. In addition, this should be complemented by the holistic and observational role of the coach.

In Situ Neutron Diffraction Study of Strain Evolution and Load Partitioning During Elevated Temperature Tensile Test in HIP-Treated Electron Beam Powder Bed Fusion Manufactured Ti-6Al-4V

In Situ Neutron Diffraction Study of Strain Evolution and Load Partitioning During Elevated Temperature Tensile Test in HIP-Treated Electron Beam Powder Bed Fusion Manufactured Ti-6Al-4V

Comparison of biomechanical characteristics of the Schneiderian membrane with different transcrestal sinus floor elevation techniques using three-dimensional finite element analysis

ObjectiveThe aim of this study was to establish a three-dimensional finite element (FE) hydraulic pressure technique model and compare the biomechanical characteristics of the osteotome technique and the hydraulic pressure technique using three-dimensional finite element analysis (FEA).MethodsThree FE models were created: the hydraulic pressure technique (M1), the osteotome technique with a Ø 1.6-mm osteotome (M2), and the osteotome technique with a Ø 3.0-mm osteotome (M3) models. Three models were simulated via computer-aided design software, with the sinus membrane elevated to 1, 3 and 5 mm, after which the required loading force was recorded. Stress distribution, including the equivalent von Mises stress, tensile stress, compressive stress, shear stress, as well as strain (i.e., sinus membrane displacement in horizontal dimensions) of the three models were subsequently examined and statistically compared.ResultsOverall, the required loading force, stress and strain increased as the elevation height increased. The loading force required to elevate the sinus membrane to 1,3 and 5 mm in M1 was 24.9 kPa, 77.1 kPa and 130 kPa, comparing 32.5 kPa, 112. 9 kPa and 200.8 kPa in M2 as well as 54.5 kPa, 160.6 kPa and 273.2 kPa in M3. Under the same elevation height, M1 exhibited the least von Mises stress (P<0.001), as well as the largest horizontal sinus membrane displacement (P<0.001).ConclusionsIt can be seen from the FEA results that the hydraulic pressure technique enables a greater portion of the sinus membrane to detach from the sinus floor while exerting less stress on the mucosa when the sinus membrane is elevated up to 5 mm. Based on this study, the hydraulic pressure technique was found to be safer and more effective than the osteotome technique under the same elevation height.

Conceptualizing a load and volume autoregulation integrated velocity model to minimize neuromuscular fatigue and maximize neuromuscular adaptations in resistance training.

Resistance training (RT) load and volume are considered crucial variables to appropriately prescribe and manage for eliciting the targeted acute responses (i.e., minimizing neuromuscular fatigue) and chronic adaptations (i.e., maximizing neuromuscular adaptations). In traditional RT contexts, load and volume are generally pre-prescribed; thereby, potentially yielding sub-optimal outcomes. A RT concept that individualizes programming is autoregulation: a systematic two-step feedback process involving, (1) monitoring performance and its constituents (fitness, fatigue, and readiness) across multiple time frames (short-, moderate-, and long-term); and (2) adjusting programming (i.e., load and volume) to elicit the targeted goals (i.e., responses and adaptations). A growing body of load and volume autoregulation research has accelerated recently, with several meta-analyses suggesting that autoregulation may provide a small advantage over traditional RT. Nonetheless, the existing literature has typically conceptualized these current autoregulation methods as standalone practices, which has limited their extensive utility in research and applied settings. The primary purpose of this review was three-fold. Initially, we synthesized the current methods of load and volume autoregulation, while disseminating each method's main advantages and limitations. Second, we conceptualized a theoretical Integrated Velocity Model (IVM) that integrates the current methods for a more holistic perspective of autoregulation that may potentially augment its benefits. Lastly, we illustrated how the IVM may be compared to the current methods for future directions and how it may be implemented for practical applications. We hope that this review assists to contextualize a novel autoregulation framework to help inform future investigations for researchers and practices for RT professionals.

Molecular Mechanisms of Vascular Tone in Exercising Pediatric Populations: A Comprehensive Overview on Endothelial, Antioxidative, Metabolic and Lipoprotein Signaling Molecules

Vasoactive molecules are central regulators of vascular tone, angiogenesis and inflammation. Key molecular agents include nitric oxide (NO), endothelin-1 (ET-1), prostacyclin, free triiodothyronine (fT3), leptin, low-density lipoprotein (LDL), high-density lipoprotein (HDL), superoxide dismutase (SOD), and glutathione peroxidase (GPX). Dysregulation of these compounds can lead to endothelial dysfunction, an early predictor of atherosclerosis and cardiovascular diseases (CVD). Maintaining endothelial health is thus essential for vascular homeostasis and cardiovascular risk prevention. Regular exercise serves as a vital protective measure against CVD and the risk of cardiovascular conditions. However, young athletes often significantly exceed recommended levels of training load, engaging in highly intensive training that leads to substantial physiological adaptations. Despite this, research on the impact of exercise on vasoactive substances in children and adolescents, particularly young athletes, is limited and inconsistent. Most studies focus on those with pre-existing conditions, like obesity or diabetes mellitus. Existing findings suggest exercise may favorably affect vascular biomarkers in youth, but methodological variations hinder consistent conclusions. This literature review examines 68 studies on the effects of exercise on vascular molecules in children and adolescents, young athletes, and children and adolescents with pre-existing conditions, offering deeper insights into how exercise may influence vascular health at the molecular level.

Experimental study on modal analysis and vibration response of tunnel structures under different damage conditions due to subway train loads

Based on a prototype of the Beijing subway tunnel, this research conducts large-scale model experiments to systematically investigate the vibration response patterns of tunnels with different damage levels under the influence of measured train loads. Initially, the polynomial fitting modal identification method (Levy) and the model test preparation process are introduced. Then, using time-domain peak acceleration, frequency response function, frequency-domain modal frequency, and modal shape indicators, a detailed analysis of the tunnel’s dynamic response is conducted. The results indicate that damage significantly amplifies vibration acceleration, with the amplification increasing with the severity of the damage. When the crack lengths are 2 cm, 4 cm, and 6 cm, the peak acceleration increases by 25.12%, 36.35%, and 50.29%, respectively, while adjacent segments show increases of 13%, 29%, and 45%. Damage decreases the tunnel structure’s modal frequency, with the first two modal frequencies showing the most significant reductions of 9.87% and 7.34%, respectively. The adjacent segments show reductions of 7.7% and 4.2%. As the severity of the damage increases, the amplitude of the modal shape at the damaged location also increases, with the first modal shape rising by 43.37% for 4 cm damage compared to 2 cm damage and by 72.21% for 6 cm damage. The second modal shape increases by 9.04% and 26.51%, respectively. Additionally, the effectiveness of the polynomial fitting modal identification method (Levy) for tunnel structural damage detection was validated. Finally, based on the methods outlined above, the tunnel responses measured on-site in the Beijing metro were also analyzed. The findings of this study provide important theoretical support for the assessment and routine maintenance of metro tunnels.

Cardiac myosin binding protein C correlate with cardiac troponin I during an exercise training program in patients with HFrEF.

Cardiac myosin binding protein C (cMyC) is an emerging new biomarker of myocardial injury rising earlier and cleared faster than cardiac troponins. It has discriminatory power similar to high-sensitive troponins in diagnosing myocardial infarction in patients presenting with chest pain. It is also associated with outcome in patients with acute heart failure. It is currently unclear how it relates to cardiac troponins in patients with chronic heart failure undergoing exercise training. This is a post hoc analysis of symptomatic heart failure patients in the multicentre randomized SMARTEX trial. Patients were randomized to one of three arms: high-intensity interval training, moderate continuous training and recommendation of regular exercise serving as control group (CG) for 12weeks. As the training load in the two intervention arms was similar, these patients were merged and constituted the intervention group (IG). Clinical data and measurements were obtained at baseline and at 12weeks. In 205 patients, serum was available for cMyC testing and in 196 patients, serum was available for hs-cTni testing. Due to non-normal distribution, cMyC and hs-cTnI measurements were log-transformed. A Bland-Altman plot was employed to evaluate the agreement of cMyC with hs-cTnI measurements. Lastly, a linear regression model was applied. No significant differences were observed in the change of cMyC levels between the groups throughout the intervention period (∆ cMyC IG: -0.5 [IQR: -3.4; 2.1] vs. ∆ cMyC CG: -0.7 [IQR: -2.7; 2.6]). The change in log hs-cTnI was significantly correlated with the change in log cMyC during the 12-week intervention period, with a Pearson correlation coefficient of R=0.52 (95% CI 0.37-0.66, P<0.001). For every 10% increase in cMyC levels, hs-cTnI levels rose by approximately 5%. Changes in levels of the novel biomarker cMyC were significantly associated with hs-cTnI serum levels in patients with symptomatic chronic HFrEF during a structured 12-week exercise training programme. This may indicate that cMyC has a role as a future marker of subclinical myocardial damage.

Features of adaptation of the bioenergetics system of the organism of young athletes to physical loads

Training of young athletes in modern conditions is characterized by the use of increased volumes and high intensity of training loads. The educational and training process in various sports involves the use of various schemes and approaches to training. The article identifies the physiological mechanisms of reactions of the body of young athletes to the muscular activity of the main energy systems. Such an approach is necessary for the scientific support of planning training programs at different stages of preparation. The study involved young athletes specializing in swimming and water polo. As part of the natural training process, a three-stage comprehensive examination was carried out for each specialization. The aim of the work was to identify individual adaptations of the athlete's body to physical exertion. As a result of the study, it was found that swimmers and water polo players demonstrate certain differences in the ratio of aerobic and anaerobic energy supply during intense muscle work. This is explained by differences in the focus of the training process and the specifics of their motor activity. Analysis of the study results revealed four main options for individual adaptation of the body of young athletes to physical exertion. This approach allowed for adjustments to individual training plans.

Design methodology for heavy-haul railway track foundations under 40-tonne axle loads

ABSTRACT Heavy haul railway, recognized for high capacity and efficiency, is gaining traction worldwide. However, heavier axle loads can accelerate track and foundation deterioration without robust structural design. This study proposes a practical design methodology for heavy-haul track foundations under 40-tonne axle loads. Short axle spacing was considered in analyzing train load distribution, revealing significant stress superposition on the subgrade. Based on general strength, deformation, and long-term stability, a standardized multi-axle load pattern (4Z1800/2400) is introduced to capture these effects. The recommended design ensures cumulative deformation remains within the subgrade “working zone” by integrating induced stress levels and fill materials, surpassing single-factor approaches. Long-term stability, indicated by cumulative deformation approaching slow convergence, serves as the control requirement. Proposed design solutions include: 1) roadbed thickness of 3.5 m, with subgrade reaction modulus (K30) ≥110 MPa/m below the roadbed; 2) lower roadbed of 2.3 m, K30 ≥130 MPa/m, with thickness adjustments as needed; 3) upper roadbed of 0.7 m using high-quality graded gravel. These measures effectively control deformation, thus ensuring the performance and longevity of heavy-haul track foundations under extreme axle loads. The outcomes support global heavy-haul development.

Implementing Training Load Monitoring in Tactical Populations

ABSTRACT The monitoring and optimizing training load is a concept designed to decrease risk of injury while improving physical fitness and performance. This area has grown significantly in popularity, especially in the sporting world. However, these principles can be applied to other populations, such as tactical personnel who likewise are at increased risk of injury and engage in physically demanding occupational tasks that require sufficient fitness. Although monitoring the training load in tactical personnel may be effective, the critical differences between athletic and tactical populations necessitate occupationally specific load monitoring programs. This article aims to identify these barriers and suggests potential solutions for practitioners and researchers.

A New Design of Composite Pavement with Asphalt Interlayer between CRCP and Cement Treated Base Course

In Japan, composite pavements are adopted in expressways to ensure a long service life with minimum maintenance work. A typical design of the composite pavement utilizes a porous asphalt surface and a CRCP over a cement treated base course (CTB). An investigation on a 20 years old composite pavement revealed that the CTB was damaged due to water penetration and erosion. This finding promoted us to develop a new type of composite pavement, which introduces an asphalt interlayer (AIL) over the CTB to prevent the erosion. A structural design method for the new design of the new composite pavement was developed based on thermal and load stress calculations and fatigue analysis. Full scale test composite pavements were constructed and thermal and load strains measured on the pavements. A 3DFEM model was developed for stress calculation and validated by comparing the calculated and measured strains. The new design method provides 10 % reduction of fatigue damage by introducing AIL. It was also found that the fatigue damage increases six times if AIL is not used and CTB is eroded.

Numerical and Experimental Investigation of an Extradosed Cable-Stayed Bridge in Urban Rail Transit Under Dynamic Train Load

With the urban rail transit construction boom, more and more extradosed cable-stayed bridges have been built and put into service in the urban rail transit lines, due to the advantages of aesthetic appearance and high stiffness. There are distinct dynamic characteristics of the metro train and extradosed cable-stayed bridge system, which have rarely been explored. This paper presents the numerical and experimental investigation of an extradosed cable-stayed bridge under dynamic train load in urban rail transit with the maximum span among its type of bridge in China. Three vehicle modes with different degrees of freedom and two bridge finite element models are adopted to perform the dynamic analysis of the metro train and extradosed cable-stayed bridge system. Moreover, the bridge is instrumented in a comprehensive field measurement campaign including ambient vibration testing, static load testing, and dynamic load testing. The collected modal parameters and static and dynamic responses of the bridge are employed to validate the established numerical models. Dynamic characteristics of the analyzed bridge are subsequently explored. In particular, dynamic effects of the main components including the main girder, pylons, and inclined cables are examined considering a variety of operational conditions. This study provides an effective method for analyzing the dynamic responses and valuable insights into the dynamic performance of large-span extradosed cable-stayed bridges under metro train load in urban rail transit.

Progressive Training Program Improves Aerobic Capacity and Physical Fitness in Student Soccer Athletes

The endurance of soccer players in Indonesia is generally still low. Aerobic capacity is an important component for improving physical fitness and endurance. When comparing several age groups, young players have less physical fitness. This study aimed to determine the effects of progressive training on changes in the maximum oxygen volume (VO2max) and heart rate (HR) based on recovery time. This study is quasi-experimental with a control group design and was conducted on student soccer athletes. Sixty athlete students who met the inclusion criteria were divided into a control group (n=30) and a progressive training group (n=30). The intervention consisted of progressive training for ten weeks with marathon running at distances of 150, 200, and 300 meters with rest intervals for each distance. The training load was gradually increased by increasing the number of repetitions every week. VO2 max, and Heart Rate were evaluated before and after the program. The results shown that the VO2 max was significantly different between the groups (p&lt;0.001), and the Heart Rate of the subjects in both groups decreased from start to finish. Notably, the HR in the progressive training group was lower than the control group. In conclusion, progressive training is effective in improving aerobic capacity and physical fitness.

Monitoring Sleep and Nightly Recovery with Wrist-Worn Wearables: Links to Training Load and Performance Adaptations.

Previous studies on the effects of intensified training on sleep quality/quantity have been somewhat contradictory. Moreover, recreational athletes often track various sleep metrics, and those metrics' actual connections to training adaptations are unknown. This study explored the effects of intensified training on sleep and nightly recovery along with their associations with training adaptations. A total of 24 participants (10 females) performed a 3-week baseline training period (BL), a 2-week overload period (OL), and a 1-week recovery period (REC), which were followed by test days (T1-T3). The endurance performance was assessed with a 3000 m running test. Throughout all of the periods, the nightly recovery information was monitored with a wrist-worn wearable, including sleep quantity and quality, heart rate (HR) and HR variability (HRV), and proprietary parameters combining several parameters and scaling the results individually. In addition, the perceived strain and muscle soreness were evaluated daily. The 3000 m running performance improved from T1 to T2 (-1.2 ± 1.7%, p = 0.006) and from T1 to T3 (-1.7 ± 1.2%, p = 0.002). The perceived strain and muscle soreness increased (p < 0.001) from the final week of the BL to the final week of the OL, but the subjective sleep quality and nightly recovery metrics remained unchanged. The OL average of the proprietary parameter, autonomic nervous system charge ("ANS charge", combining the HR, HRV, and breathing rate), as well as the change in the sleep HR and HRV from the BL to the OL, were associated (p < 0.05) with a change in the 3000 m running time. In conclusion, the subjective recovery metrics were impaired by intensified training, while the sleep and nightly recovery metrics showed no consistent changes. However, there were substantial interindividual differences in nightly recovery, which were also associated with the training adaptations. Therefore, monitoring nightly recovery can help in recognizing individual responses to training and assist in optimizing training prescriptions.

Effects of preferred music on internal load in adult recreational athletes: a systematic review and meta-analysis.

When exercising to preferred music (PM), participants found more satisfaction and less typical exercise-related fatigue, which made it easier and more enjoyable to maintain the physical activity (PA) until the exercise goals were achieved. The purpose of this review and meta-analysis was to determine whether changes on internal training load in adult recreational athletes were modified by listening to PM and non-preferred music (NPM), during different PA. A music-focused search was performed on the Google Scholar, PubMed, and Web of Science databases to identify relevant articles to this topic published after 2000 to investigate the effects of PM on psychophysiological responses to PA. Twelve studies met the inclusion criteria and were included in the qualitative analysis. The research studies' sample sizes varied from ten to twenty-five participants. Heart rate (HR) and rate of perceived exertion (RPE) on internal training load were the selected indicators. The use of different kinds of music had mostly, non-significant effects on HR and RPE toward the ability of music to allow participants to dissociate from the intensity level they are experiencing. The meta-analysis confirmed that preferred music had no significant effect on HRmean or RPE. The results of this review contradict the idea that listening to music improves exercise performance.

Adjusting the Yo-Yo IRT-1 equation to estimate VO2max of sub-elite football referees: a gender-comparative study.

To gain optimal positioning to make sure the game laws are applied in uniform way, the performance of field referee must be periodically evaluated to have constantly adequate training during a match and during the competitive season. Considering that field Yo-Yo Intermittent Recovery Test-Level 1 is frequently employed in elite team sport players to estimate maximal oxygen uptake (VO<inf>2max</inf>) in field settings, the aim of this cross-sectional, gender-comparative study was to develop a new adjusted Yo-Yo-1 equation for estimating VO<inf>2</inf>max in football referees. During off-season, 20 male (21.2±3.6 yrs) and 20 female (22.5±4.6 yrs) sub-elite football referees underwent laboratory treadmill test and Yo-Yo-1. VO<inf>2max</inf> during Yo-Yo-1 and laboratory treadmill test were significantly correlated in the whole sample (r=0.871; P<0.0001), women (r=0.861; P<0.0001) and men (r=0.800; P<0.0001). Only in women VO<inf>2max</inf> during Yo-Yo-1 was lower than laboratory treadmill test (-4.3%; P=0.014). Adjusted formulae (pooled and gender-based) allowed to mitigate the underestimated values of laboratory treadmill test of VO<inf>2max</inf> found with the Bangsbo's equation (pooled sample: -14.9%, P<0.0001; women: -13.2%, P<0.0001; men: -16.4%, P<0.0001). Adjusted Yo-Yo-1 equations allow to accurately monitor changes in cardiopulmonary performance, and based on this, administer constantly adequate training loads, in male and female field referees.