Internal Load Parameters Research Articles

Analyzing the impact of non-participation in the FIFA World Cup Qatar 2022 on LaLiga players' physical performance.

Monitoring external load demands in soccer is crucial for optimizing performance and reducing injury risk. However, events like the FIFA World Cup Qatar 2022 and unexpected interruptions can disrupt load management strategies. Understanding the impact of such events on player performance is essential for effective training and recovery strategies. This study retrospectively assessed the impact of the FIFA World Cup Qatar 2022 on the physical performance of LaLiga elite soccer players who were not part of the tournament. The aim was to analyze various external load parameters and determine the direction of their changes post-tournament. Data from 239 LaLiga players who were not selected for the World Cup were analyzed. External load parameters from 8 matches before and after the tournament were compared. Statistical analyses, including repeated measures ANOVA, were conducted to evaluate changes in performance metrics. Minutes played and total distance covered showed no significant changes post-tournament. However, maximal speed decreased significantly (p < 0.001; η2p = 0.117). High-speed running parameters improved significantly (p < 0.05), except for HSRRelCount (p = 0.074; η2p = 0.013). Sprint-related variables demonstrated significant enhancements, except for SprintAbsAvgDuration, SprintMaxAvgDuration, and Sprints >85% Vel Max. Acceleration metrics showed significant improvements in Accel_HighIntensityAccAbsCount (p = 0.024; η2p = 0.021), while Accel_Accelerations showed no significant changes. Deceleration metrics remained unchanged, but Accel_HighIntensityDecAbsCount and Accel_HighIntensityDecAbsDistance increased significantly post-tournament (p = 0.002; η2p = 0.040, p = 0.001; η2p = 0.044, respectively). Non-participant LaLiga players demonstrated enhanced performance in most external load metrics after the FIFA World Cup Qatar 2022. These findings highlight the importance of effective load management during periods of competition interruption and suggest strategies to optimize performance and reduce injury risk. Further research should consider holistic performance metrics and internal load parameters to provide comprehensive insights into player response to mid-season tournaments.

Concurrent validation of the resistance intensity scale for exercise for monitoring velocity-based training with elastic bands

The aim was to evaluate the concurrent validity and reliability of the Resistance Intensity Scale for Exercise [RISE], which uses verbal descriptors, to quantify the intensity in velocity-based training with elastic bands. Eighteen trained volunteers performed parallel squats at maximum speed at 40%, 55%, 70%, and 85%1RM in four sessions, two for familiarization and two for reliability. Each set was stopped at a 10% intra-set velocity loss. Participants reported the perceived effort (easy-low-moderate-hard-maximal) at the first and last repetition. The concurrent validation was conducted with external load (i.e., mean propulsive velocity, weight, repetitions, and maximum power) and internal load parameters (i.e., heart rate). Participants' relative strength was calculated to assess its influence on the dependent variable. Acceptable concurrent validity and reliability (ICC>0.77, CV<21%) were observed, with the perceived effort being appropriate to differentiate between intensities and not being influenced by the participants’ relative strength (p = 0.88). A categorical linear regression showed significant (p < 0.001) associations between the RISE scores and the weight, repetitions, and mean propulsive velocity (r = 0.43–0.63). The findings certify the usefulness of the perceived exertion for quantifying the intensity during velocity-based training with elastic bands. The perceived exertion of the first and last repetition favors a proper dosage of the training load.

Balancing the load: A narrative review with methodological implications of compensatory training strategies for non-starting soccer players.

New training approaches have emerged advocating for the implementation of compensatory physical training. This approach aims to provide additional training that balances the load typically experienced by non-starters during a match. This may help maintain their readiness and ensures that their physical fitness is not compromised by the reduced exposure to match loads. Thus, this narrative review aims to describe the differences in external loads between starting and non-starting players and describe the studies conducted in compensatory training. Studies examining external load metrics such as total distances covered, high-speed running, and sprinting suggest that, adjusted for playing time, values are often higher in non-starting players. Although not standardized, there is an obvious decrease in exposure for these critical variables in non-starters. Additionally, internal load parameters such as perceived exertion and heart rate tend to be higher in starting players. Regarding the physical fitness impacts, evidence suggests differences observed between starters and non-starters in some aspects of physical performance, although the extent and significance of these differences can vary. The studies on compensatory training are limited, and the typical approach usually centres on running-based exercises and small-sided games, offering differing approaches to address the physical needs. The gap in research underscores the necessity for improved study designs that can shed light on the real impact of compensatory training. Presently, the practice of compensatory training has been adopted, yet a definitive understanding of its genuine influence, particularly in terms of enhancing physical fitness and mitigating injury risks, remains elusive.

Validity and reproducibility of match-derived ratios of selected external and internal load parameters in soccer players: A simple way to monitor physical fitness?

The study aim was to assess whether match-derived external-to-internal load ratios are a valid and reliable tool to measure physical fitness. Sixteen elite youth soccer players (17 ± 1 years) performed two maximal fitness tests. Subsequently, players participated in three intra-squad soccer matches in three consecutive weeks. Three GPS-based parameters of external load (total distance, PlayerLoad, high-intensity distance) were divided by three heart rate-based parameters of internal load (iTRIMP, Banister TRIMP, average percentage heart rate reserve) for the ratio calculations. Validity was established by comparing the ratios with results of the fitness tests, while between-athlete and within-athlete reliability were quantified. Most integrated load ratios were moderately-to-largely correlated with the various fitness parameters. Overall, a ratio consisting of PlayerLoad and average percentage heart rate reserve demonstrated the most consistent correlations with maximum treadmill speed (r = 0.69, P = 0.003) and the speeds associated with 4 mmol/L of blood lactate (r = 0.56, P = 0.024) and 80% of heart rate reserve (r = 0.54, P = 0.031). Most of the ratios displayed acceptable levels of reproducibility (intraclass correlation coefficient > 0.8 and coefficient of variation < 10%), with the minimal detectable change of all ratios ranging between 7.1 and 37.8%. Given their associations with physical fitness and non-invasive nature, certain external-to-internal load ratios may be used to monitor physical fitness in soccer players. However, the ratios may not be sensitive enough to detect small yet practically relevant alterations in player fitness.

Monitoring training load in youth soccer players: effects of a six-week preparatory training program and the associations between external and internal loads

This study examined the effects of a six-week preparatory training program on physical performance and physiological adaptations in junior soccer players. Additionally, we investigated whether a relationship existed between external and internal loads. Youth soccer players (aged 16 years old) from a youth football academy participated in six weeks of pre-conditioning training. Wireless Polar Team Pro and Polar heart rate sensors (H10) were used to monitor physical performance indicators (sprint and acceleration scores, covered distance, maximum and average speed and duration), physiological responses (maximum and average heart rate [HR] and R-R interval, time in HR zones 4+5, and heart rate variability [HRV]), and training load score. Additionally, muscle status and rating of perceived exertion (RPE) scores were measured using digital questionnaires. Significant increases were observed in the majority of physical performance indicators [i.e., sprints (p = 0.015, ES = 1.02), acceleration (p = 0.014, ES = 1), total distance (p = 0.02, ES = 0.87), as well as maximum speed (p = 0.02, ES = 0.87)]. A trend towards improvement was observed in the remaining performance indicators (i.e., distance/min and avg speed; ES = 0.6), training load (ES = 0.2), muscle status (ES = 0.3)), and all physiological responses parameters (ES = 0.1 to 0.6). Significant correlations were found between the majority of external load parameters (i.e., performance indicators) and objective (i.e., physiological responses) and subjective (i.e., RPE, muscle status) internal load parameters (p < 0.001). The highest number of moderate-large correlations were registered between performance indicators and time in HR zone 4+5 (0.58 < r < 0.82), training load (0.53 < r < 0.83), average HR (0.50 < r < 0.87), maximal HR (0.51 < r < 0.54) and average R-R interval (0.58 < r < 0.76). HR zone 4+5, average and maximal HR, average R-R interval, and training load score may help control training parameters and reduce the risk of under- or over-training in youth soccer players. However, these conclusions should be confirmed and replicated in future studies with more diverse subject populations.

The relationship between external and internal load parameters in 3 × 3 basketball tournaments

Purpose3 × 3 basketball games are characterized by high-intensity accelerations and decelerations, and a high number of changes of direction and jumps. It is played in tournament form with multiple games per day. Therefore, optimal regeneration is crucial for maintaining a high performance level over the course of the tournament. To elucidate how load of a match affects the athletes' bodies (i.e., internal load), muscular responses to the load of 3 × 3 games were analyzed. We aimed to investigate changes in contractility of the m. rectus femoris (RF) and m. gastrocnemius medialis (GC) in response to the load of single 3 × 3 games and a 3 × 3 tournament.MethodsInertial movement analysis was conducted to capture game load in 3 × 3. Changes in contractility were measured using tensiomyography (TMG). During a two-day tournament, TMG measurements were conducted in the morning and after each game. Additionally, off-game performance analysis consisting of jump and change-of-direction (COD) tests was conducted the day before the tournament.ResultsSignificant changes of the muscle contractility were found for GC with TMG values being higher in the baseline than in the post-game measurements. In contrast to athletes of the GC group, athletes of the RF group responded with either decreased or increased muscle contractility after a single 3 × 3 game. A significant correlation between external and internal load parameters could not be shown. Concerning off-game performance, significant correlations can be reported for COD test duration, CMJ height and ∆Vc as well as COD test duration and ∆Dm. No systematic changes in muscle contractility were found over the course of the tournament in RF and GC.ConclusionThe athletes' external 3 × 3 game load and their performance level did not seem to affect muscular contractility after a single 3 × 3 game or a complete 3 × 3 tournament within this investigation. This might indicate that elite athletes can resist external load without relevant local muscular fatigue. With respect to the course of the tournament, it can therefore be concluded that the breaks between games seem to be sufficient to return to the initial level of muscle contractility.

Effect of Sodium Bicarbonate Supplementation on Muscle Performance and Muscle Damage: A Double Blind, Randomized Crossover Study

Sodium bicarbonate (NaHCO3) has been used as an ergogenic substance during high-intensity exercises. Therefore, the aim of the present study was to investigate the effects of NaHCO3 supplementation on external and internal load parameters during isokinetic exercise in trained subjects. Ten subjects were tested on two occasions: after ingesting 0.3 g.kg-1 of body mass of NaHCO3 or placebo. Maximum voluntary isometric contraction was performed before and after a dynamic protocol consisting of 10 series of 10 movements of flexion/extension of the knee extensors at 120° s-1 at an interval of 60 s between series. Outcomes considered were: peak torque (isokinetic dynamometry), blood lactate and creatine concentration (CK), analysis of perceptions of effort (OMNI scale), pain (visual analog scale) and recovery (scale raging 6 to 20). Performance was assessed using peak torque values. Muscle damage was assessed prior and 24 h post exercise. The subjective perceptions of effort, pain and recovery were assessed at different times and the internal load of the session was assessed 30 min post-effort. Although significant reductions in peak torque were noted both in isometric (NaHCO3:-29.11 ± 22.95%, Placebo: −23.51 ± 15.23%; p = 0.38) and isokinetic strength (NaHCO3:-23.0 ± 13.9%, Placebo:-19.6 ± 9.1%; p = 0.09), there was no effect of supplementation on performance (p > 0.05). The blood CK concentrations (NaHCO3: pre:225.3 ± 135.9 U/L, post: 418.4 ± 318.4 U/L; Placebo: pre:238 ± 94.03 U/L, post:486 ± 336.6 U/L) increased after protocol (p = 0.005), however, without differences between conditions. In conclusion, the NaHCO3 did not attribute benefits in performance or in parameters related to the internal load of exercise.

Study of the Load Forecasting of a Wet Mill Based on the CEEMDAN-Refined Composite Multiscale Dispersion Entropy and LSTM Nerve Net

To address the problem of wet ball milling in a strong noise environment, it is difficult to accurately detect the internal load parameters of the cylinder during grinding. In this paper, a mill load parameter prediction method is proposed based on complementary ensemble empirical mode decomposition (CEEMDAN)-refined composite multiscale dispersion entropy (RCMDE) and-long and short-term memory (LSTM) neural networks. Using this method, the vibration signals of the mill barrel under strong noise were decomposed using the CEEMDAN algorithm, sensitive modal components with strong correlation with the original signal were selected for reconstruction using the correlation coefficient method, and features of the reconstructed signals under different load parameters were extracted through RCMDE. The load characteristic vector of an RCMDE mill was used as the input of LSTM neural networks, and the filling rate, material and ball ratio, and grinding concentration were used as the output to establish the internal load prediction model of wet mill. Experiment results show that the prediction method has a high accuracy, with average absolute percentage errors of the filling rate, feed-to-ball ratio, and grinding concentration of 6.08%, 3.50%, and 3.47%, and average absolute errors were of 0.0167, 0.0146, and 0.0146, respectively.

Factors Influencing Creatine Kinase Response in Youth National Team Soccer Players

Previous studies have examined the relationship between external training load and creatine kinase (CK) response after soccer matches in adults. This study aimed to build training- and match-specific CK prediction models for elite youth national team soccer players. Training and match load will have different effects on the CK response of elite youth soccer players, and there will be position-specific differences in the most influential external and internal load parameters on the CK response. Prospective cohort study. Level 4. Forty-one U16-U17 youth national team soccer players were measured over an 18-month period. Training and match load were monitored with global positioning system devices. Individual CK values were measured from whole blood every morning in training camps. The dataset consisted of 1563 data points. Clustered prediction models were used to examine the relationship between external/internal load and consecutive CK changes. Clusters were built based on the playing position and activity type. The performance of the linear regression models was described by the R2 and the root-mean-square error (RMSE, U/L for CK values). The prediction models fitted similarly during games and training sessions (R2 = 0.38-0.88 vs 0.6-0.77), but there were large differences based on playing positions. In contrast, the accuracy of the models was better during training sessions (RMSE = 81-135 vs 79-209 U/L). Position-specific differences were also found in the external and internal load parameters, which best explained the CK changes. The relationship between external/internal load parameters and CK changes are position specific and might depend on the type of session (training or match). Morning CK values also contributed to the next day's CK values. The relationship between position-specific external/internal load and CK changes can be used to individualize postmatch recovery strategies and weekly training periodization with a view to optimize match performance.

Reproducibility of Internal and External Training Load During Recreational Small-Sided Football Games

ABSTRACT Purpose: The aim of this study was to evaluate the reproducibility of internal and external load parameters during recreational small-sided football games. Methods: Ten healthy untrained young adult males (age: 20.2 ± 1.9 yr, body mass: 69.2 ± 6.3 kg, height: 175.4 ± 5.9 cm, body fat: 19.7 ± 5.2%) performed two 2 × 20-min sessions of four versus four plus goalkeeper small-sided games (SSG) 1 week apart on a standard, outdoor, 40 × 20-m artificial grass pitch. Twelve external (total distance, peak speed, player load, work rate and distance covered at 0–2, 2–5, 5–7, 7–9, 9–13, 13–16, 16–20 and >20 km/h) and seven internal load parameters (heart rate and time spent in different heart rate zones [<70%, 71–80%, 81–90%, 91–95%, 96–100%, 91–100%]) were measured. Reproducibility was reported as intraclass coefficient correlation (ICC), the coefficient of variation (CV), and the typical error of measurements (TE). Results: No statistical differences (p> .05) between sessions were found in any measures. Minimal test-retest variability was noted for mean and peak heart rate (HRpeak) relative to HRpeak with CV values of 3.4% and 2.6%, respectively. Acceptable variability (CV<10%) was demonstrated for total distance covered, distance covered at 2–5 km/h, and peak speed. Distance covered in different speed zones (CV = 15.7–47.6%) and percentage of time in each HR zone showed large-to-very large variability (CV = 36.2–128.4%). Mean heart rate (HRmean), HRpeak, distance covered at 5–7, 13–16 and >20 km/h, and percentage of time above 95%HRpeak were the most reliable variables (ICC = 0.74–0.79), followed by total distance covered, peak speed, and percentage of time at 80–90% HRpeak (ICC = 0.39–0.67). The lowest reliability was observed for distance covered in the moderate speed zones 7–9 km/h (ICC = 0.12) and 9–13 km/h (ICC = −0.09), and percentage of time at 70–80% HRpeak (ICC = −0.01). Conclusions: Small-sided games can be used when planning training-induced exercise responses in relation to total distance covered, peak speed, and mean heart rate. This evidence further supports the use of SSG when organizing recreational football training, in young adult males, with the purpose of improving health profile due to the high reproducibility of HRmean and total distance covered.

Relación entre la complejidad técnico-táctica en la sesión de entrenamiento y la carga interna en baloncesto femenino

&lt;p&gt;El objetivo de este trabajo fue analizar la Escala de Valoración de la Carga del entrenamiento Técnico-Táctico (Coque, 2009) y su relación con parámetros de carga interna. En la actualidad, se plantea un modelo de planificación que se caracteriza por la preocupación de mejorar la interpretación que el sujeto hace de lo que sucede a su alrededor durante la competición (Martín Acero, Seirul-lo Vargas, Lago Peñas, y Novoa Lalín, 2013), para así modificar la respuesta y a su vez, el esquema motriz. El estudio contó con las jugadoras del equipo de Liga Femenina del Club Baloncesto Conquero, compuesto por 12 jugadoras, con edades comprendidas entre 17 y 33 años (M = 21.91; SD = 4.81). Los datos fueron recogidos durante los dos últimos meses de competición que se corresponden con los meses de febrero y marzo de 2016. Para obtener los datos necesarios se utilizaron la escala de valoración subjetiva de la carga de entrenamiento Técnico-Táctico (Coque, 2009), la percepción subjetiva del esfuerzo (Borg, 1970; 1998; Borg &amp;amp; Kaijser,2006) y la calidad de la recuperación (Kentta &amp;amp; Hassmen, 1998). Los resultados mostraron que sólo la densidad del entrenamiento es el único marcador que podría explicar, de forma importante (91.4%), el esfuerzo percibido de las jugadoras. Según los datos obtenidos la percepción subjetiva del esfuerzo podría ser utilizada para la monitorización del entrenamiento en cuanto a la complejidad técnico-táctica del mismo.&lt;/p&gt;

Monitoring Internal Load Parameters During Competitive Synchronized Swimming Duet Routines in Elite Athletes

The aim of the study is to compare the heart rate (HR) and rate of perceived exertion (RPE) responses as internal load indicators while performing duet routines during training and competition, both in the technical and free programs of synchronized swimming (SS). Participants were 10 SS Olympic medalists (age, 17.4 ± 3.0 years; height, 164.0 ± 6.1 cm; body mass, 52.0 ± 6.4 kg; training, 36.3 ± 6.2 h·wk; experience, 9.2 ± 2.6 years). They were monitored while performing the same technical duet or free duet, during a training session (T) and during an official competition (C). Heart rate was continuously monitored. Rate of perceived exertion was assessed using the Borg CR10 scale. Heart rate responses during T and C were almost identical: pre-exercise mean HR (b·min) was 130.5 ± 13.9 (T) and 133.6 ± 7.7 (C) and quickly increased yielding mean peak values of 184.8 ± 5.8 (T) and 184.8 ± 6.6 (C), with interspersed bradycardic events down to 86.6 ± 4 (T) and 86.3 ± 5 (C). Routines were perceived as "hard" to "extremely hard" by the swimmers in both conditions, and mean RPE scores (0-10+) were equally high during C (7.9 ± 1.2) and T (7.5 ± 1.2) (p = 0.223). Rate of perceived exertion inversely correlated with minimum (R = -0.545; p = 0.008) and mean HR (R = -0.452; p = 0.026) and positively correlated with HRrange (R = 0.520; p = 0.011). The internal load imposed by SS duets performed during training is virtually identical to that elicited in a real competitive situation. Therefore, practicing competitive routines is suitable for developing and maintaining the cardiovascular fitness that is needed for specific conditioning in elite synchronized swimmers, with the added value of favoring exercise automaticity, interindividual coordination, and artistic expression simultaneously.

Analysis of UK domestic building retrofit scenarios based on the E.ON Retrofit Research House using energetic hygrothermics simulation – Energy efficiency, indoor air quality, occupant comfort, and mould growth potential

The work forms part of the CALEBRE project (2008–2013), the aim of which was to investigate a suite of technologies and staged approaches for retrofit upgrades for ‘hard-to-treat’ solid/thin cavity masonry-walled UK domestic buildings that would i) reduce operational energy demand/carbon emissions, and ii) be acceptable and appealing to the building occupants. The E.ON Retrofit Research House (Nottingham, UK) was used as an instrumented test platform as part of this study. The retrofitting phases (and technologies) have been used as the basis for the modelling methodology in this paper, together with the corresponding envelope assemblies, material properties, climate, and internal load parameters. The approach to retrofit was to increase air tightness (reduce ACH), decrease static U-values of the external envelope (wall, floor and glazing), and upgrade heating system efficiency. This was complemented by a combination of options that included a whole-building system of mechanical ventilation with heat recovery (MVHR). These interventions were analysed alongside simulated passive buffering of variations in indoor air psychrometric conditions using conventional (clay, timber) and advanced (mesoporous silica) wall surface treatments. Each retrofit scenario was modelled using an energetic hygrothermics building performance simulation (BPS) approach to determine the combined effects of retrofit packages on indoor air psychrometric conditions, external envelope (dynamic) heat transfer, operational energy efficiency, occupant comfort, and mould growth potential. It is proposed that this approach can provide the basis for an intelligent risk management strategy to inform both the design and deployment of retrofit upgrade packages intended for residential buildings.

Monitoring Internal Load Parameters During Simulated and Official Basketball Matches

The purpose of this study was to compare the internal load responses (session rating of perceived exertion [RPE] and salivary cortisol) between simulated and official matches (SM and OM). Ten professional basketball players participated in 2 OMs and 2 SMs during the competition season. Subjects provided saliva samples 30 minutes before the prematch warm-up (PRE) and 10 minutes after the end of the match. Session RPE (CR-10 scale) was assessed 30 minutes after each match. The results from the 2-way analysis of variance showed significant differences for post-OM salivary cortisol as compared with pre-OM values (p < 0.05). No changes were observed for cortisol during the SM. Before the OM, a significant difference in salivary cortisol was observed as compared with pre-SM values (p < 0.05). Moreover, the OM session RPE was significantly greater than that of SM. There was a significant correlation between session RPE and cortisol changes (r = 0.75). In summary, the results of this study showed a greater magnitude of cortisol and session RPE responses after OM as compared with that after SM confirming the hypothesis that a real competition generates a greater stress response than a simulated condition does. The anticipatory effect was also observed in the OM. In addition, the results indicate that session RPE seems to be a viable tool in monitoring internal loads, and the results are useful in providing a better understanding of internal loads imposed by basketball training and competitions. The precise monitoring of these responses might help the coaches to plan appropriate loads maximizing recovery and performance.

Influence of motivation on physical work capacity and performance.

Influence of motivation on physical work capacity and performance.