Comparison of metabolic adaptations between endurance- and sprint-trained athletes after an exhaustive exercise in two different calf muscles using a multi-slice 31 P-MR spectroscopic sequence

Changes in the hormonal and inflammatory profile of young sprint- and endurance-trained athletes following a sports camp: a nonrandomized pretest-posttest study

BACKGROUND

The study aimed to compare catecholamine, cortisol, and immune response in sprint- and endurance-trained athletes under the same training, aiming to observe if their sport specialization affects these markers during a 9-day training camp.

METHODS

The study involved twenty-four young male (age 15.7 ± 1.6 years) and female (age 15.1 ± 1,3 years) athletes specializing in sprint and endurance athletics discipline. Blood samples for all measured parameters were taken at rested baseline, on the 4th day, and on the 9th day of training.

RESULTS

In both investigated groups a nonsignificant decrease in catecholamine levels was observed after 4 days of training, which remained stable throughout the camp. The cortisol level increased significantly in both athlete groups (sprint: T-0 vs. T-1 p = 0.0491; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-1 p = 0.0159; T-0 vs. T-3 p = 0.0005). The level of hs-CRP (sprint: T-0 vs. T-1 p = 0.0005; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-3 p = 0.0005), and myoglobin (sprint: T-0 vs. T-1 p = 0.0014; T-0 vs. T-3 p = 0.0001; endurance: T-0 vs. T-3 p = 0.0005) have increased and of hs-CRP and myoglobin level was significantly higher in sprint compared to endurance athletes (p < 0.05). The leukocyte level significantly decreased until the end of camp in both groups (sprint: T-0 vs. T-1 p = 0.0178; T-0 vs. T-3 p = 0.0175; endurance: T-0 vs. T-1 p = 0.0362; T-0 vs. T-3 p = 0.0362).

CONCLUSIONS

The applied training loads had a strong physiological impact leading to changes in stress hormones and immune responses depending on athletes` sport specialization. Training loads caused stronger responses in sprint athletes. However, both groups showed signs of severe fatigue development.

TRIAL REGISTRY

ClinicalTrials.gov ID: NCT06150105, retrospectively registered on 29.11.2023.

Age-related Decline in Renal Function is Attenuated in Master Athletes

This study analyzed the kidney function and biomarkers of health in lifelong-trained sprinters and endurance runners, and compared them to untrained aged-matched and young controls. Sixty-two men (21-66 yr.) were recruited and allocated as master athletes from sprints (n=25), master athletes from endurance events (n=8), untrained middle-aged (n=14) and young controls (n=15). Participants underwent anamnesis, anthropometric measures and blood sampling for biochemical analyses of klotho, FGF23 and estimated glomerular filtration rate. Master sprinters presented better kidney function in relation to endurance athletes and their untrained peers (P<0.0001). A number of biochemical variables were observed that negatively (i. e., GDF-15, TGF-Beta, IL-18) or positively (i. e., klotho/FGF23 ratio and sestrin-2) correlated with eGFR. Sestrin-2 presented the strongest association with eGFR (r=0.5, P=0.03). Results also revealed that lifelong-trained individuals presented the highest probability of having better values for cystatin C and thus an estimated glomerular filtration rate that was 37-49% higher than untrained peers. Master sprinters presented better kidney function in relation to endurance athletes and middle-aged untrained peers. Sestrin-2 may play a role in exercise-induced kidney function protection.

Resilience in the Endurance Runner: The Role of Self-Regulatory Modes and Basic Psychological Needs

Endurance sports certainly require an important and delicate task of mental and physical reintegration from the impact of the fatigue induced by the exertion of the sport performance. The topic of the resilience of athletes has been the theme of numerous studies, however, there are few specific works on the psychological resilience of runners. Our study aimed to investigate Resilience in Endurance Runner related to the role of Self-Regulation Modes and Basic Psychological Needs. Especially, the aim of our work was presenting a model where the gratification of the Needs of Autonomy and Competence and the level of Locomotion were the predictors of the two main components of Richardson's resilience: Homeostatic and Resilient Reintegration. The present study involved 750 endurance runners, members of the Fidal (Italian Athletics Federation). A SEM analysis was performed combining into one explanatory model the following variables: Autonomy and Competence Satisfaction, Self-Regulatory Locomotion Mode, Homeostatic and Resilient Reintegration. The model showed overall acceptable fit measurements: χ² = 872.152; CFI = 0.966; TLI = 0.952; RMSEA = 0.058. Results indicated that BPNs and SRMs are predictors of the level of resilience in endurance running athletes. In particular, Resilient Reintegration was mainly affected by Locomotion Mode (β = 0.379 for p < 0.005), which in turn received a major influence from Autonomy Satisfaction (β = 0.574 for p < 0.001). Homeostatic Recovery was found to be affected by Competence Satisfaction (β = 0.489 for p < 0.001). The study pointed out the importance of supporting in endurance runners the gratification of the needs of Autonomy and Competence as key factors capable of enhancing perseverance, timely recovery and psychophysical balance.

Energy Expenditure of Dynamic Submaximal Human Plantarflexion Movements: Model Prediction and Validation by in-vivo Magnetic Resonance Spectroscopy

To understand the organization and efficiency of biological movement, it is important to evaluate the energy requirements on the level of individual muscles. To this end, predicting energy expenditure with musculoskeletal models in forward-dynamic computer simulations is currently the most promising approach. However, it is challenging to validate muscle models in-vivo in humans, because access to the energy expenditure of single muscles is difficult. Previous approaches focused on whole body energy expenditure, e.g., oxygen consumption (VO2), or on thermal measurements of individual muscles by tracking blood flow and heat release (through measurements of the skin temperature). This study proposes to validate models of muscular energy expenditure by using functional phosphorus magnetic resonance spectroscopy (³¹P-MRS). ³¹P-MRS allows to measure phosphocreatine (PCr) concentration which changes in relation to energy expenditure. In the first 25 s of an exercise, PCr breakdown rate reflects ATP hydrolysis, and is therefore a direct measure of muscular enthalpy rate. This method was applied to the gastrocnemius medialis muscle of one healthy subject during repetitive dynamic plantarflexion movements at submaximal contraction, i.e., 20% of the maximum plantarflexion force using a MR compatible ergometer. Furthermore, muscle activity was measured by surface electromyography (EMG). A model (provided as open source) that combines previous models for muscle contraction dynamics and energy expenditure was used to reproduce the experiment in simulation. All parameters (e.g., muscle length and volume, pennation angle) in the model were determined from magnetic resonance imaging or literature (e.g., fiber composition), leaving no free parameters to fit the experimental data. Model prediction and experimental data on the energy supply rates are in good agreement with the validation phase (<25 s) of the dynamic movements. After 25 s, the experimental data differs from the model prediction as the change in PCr does not reflect all metabolic contributions to the energy expenditure anymore and therefore underestimates the energy consumption. This shows that this new approach allows to validate models of muscular energy expenditure in dynamic movements in vivo.

MR compatible ergometers for dynamic 31P MRS

Magnetic Resonance (MR) compatible ergometers are specialized ergometers used inside the MR scanners for the characterization of tissue metabolism changes during physical stress. They are most commonly used for dynamic phosphorous magnetic resonance spectroscopy (31P MRS), but can also be used for lactate production measurements, perfusion studies using arterial spin labelling or muscle oxygenation measurements by blood oxygen dependent contrast sequences. We will primarily discuss the importance of ergometers in the context of dynamic 31P MRS. Dynamic 31P MRS can monitor muscle fatigue and energy reserve during muscle contractions as well as the dynamics of recuperation of skeletal muscle tissue during the following recovery through signal changes of phosphocreatine (PCr), inorganic phosphate and adenosine triphosphate (ATP). Based on the measured data it is possible to calculate intracellular pH, metabolic flux of ATP through creatine-kinase reaction, anaerobic glycolysis and oxidative phosphorylation and other metabolic parameters as mitochondrial capacity. This review primarily focuses on describing various technical designs of MR compatible ergometers for dynamic 31P MRS that must be constructed with respect to the presence of magnetic field. It is also expected that the construction of ergometers will be easy for the handling and well accepted by examined subjects.