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Scientific Programme

Applied Sports Sciences

OP-AP16 - Training and Testing / Power and Strength IV

Date: 03.07.2024, Time: 11:00 - 12:15, Lecture room: Gala

Description

Chair TBA

Chair

TBA
TBA
TBA

ECSS Paris 2023: OP-AP16

Speaker A giuseppe coratella

Speaker A

giuseppe coratella
University of Milano, Biomedical Sciences for Health
Italy
"Muscle damage and repeated bout effect following a typical dose of Nordic hamstrings exercise"

INTRODUCTION: Nordic hamstrings exercise provides lengthening stimuli to the hamstrings with the intent to increase their resistive capacity to overstretching. While many longitudinal studies have found the effectiveness of NHE in increasing hamstrings strength and in elongating fascicles, the incorporation of NHE in the practice requires a deeper examination given the short-term effects due to the eccentric stimuli. Therefore, the present study investigated the exercises-induced muscle damage and the repeated-bout effect following a typical dose of NHE. METHODS: Thirteen active men (mean±SD; age=25.2±2.9 years; body mass=77.5±11.3 kg; height=176.4±8.4 cm) were recruited. Hamstrings eccentric strength, muscle soreness, passive range of motion (ROM), anatomical cross-sectional area and echo-intensity of biceps femoris, semitendinosus and semimembranosus were assessed at baseline, and up to four days after the NHE bout. The repeated-bout effect was examined after four weeks by repeating the same procedures. NHE session consisted of 4 x 6 repetitions. A two-way repeated-measures ANOVA as statistical analysis. RESULTS: After the first bout, hamstrings eccentric strength decreased and remained below the baseline up to three days (average loss: -25%, mean Cohen’s d effect size [ES] ranging from -3.88 to -2.95, p<0.05); muscle soreness increased two days after and remained higher up to four days (mean ES ranging from 1.30 to 1.62, p<0.05); passive ROM decreased up to four days (mean ES ranging from 0.64 to 1.62, p<0.05); anatomical cross-sectional area and echo intensity did not show any changes, both for the separate and combined muscles (p>0.05 for all comparisons). After the second bout, hamstrings eccentric strength decreased and remained below baseline up to one day (-22.5%, ES: -1.79, p<0.05); muscle soreness did not increase; passive ROM decreased up to two days (mean ES -ranging from -0.85 to -0.77); no change occurred in cross-sectional area and echo intensity. CONCLUSION: A typical dose of NHE showed impairments in muscle function but did not affect muscle structure. The current data offer novel perspectives on incorporating NHE into the weekly routine, since defining the recovery time course after a typical NHE dose. Additionally, the recovery after the second bout is much faster. In the practice, a first bout of NHE is suggested to be included far from competitions or a congested training routine, while a second bout can be safely incorporated without any meaningful impairments in the following days.

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ECSS Paris 2023: OP-AP16

Speaker B KONSTANTINOS TROMARAS

Speaker B

KONSTANTINOS TROMARAS
National and Kapodistrian University of Athens, School of Physical Education and Sports Science
Greece
"Changes in lean body mass, muscle architecture and strength with powerlifting training"

INTRODUCTION: Lean body mass (LBM) is positively correlated with powerlifting performance [1]. However, it remains uncertain whether training-induced changes in lean body mass may predict performance changes in powerlifting athletes. The purpose of the study was to investigate the correlation between changes in lean body mass and changes in powerlifting performance, before and after a short preparation period towards a major powerlifting event. METHODS: Eleven well-trained powerlifters (8 males, 3 females, age 32 ± 11 years, height 171 ± 12 cm, weight 90.9 ± 21.6 kg), participated in the study. Athletes followed 12 weeks of training aiming to maximize their performance at the national competition event. Powerlifting maximum performance expressed in Dots points (to adjust for different body masses) in squat, bench press and deadlift, body composition (dual x-ray absorptiometry), quadriceps cross sectional area and vastus lateralis muscle architecture (ultrasonography), were measured before and after the training period. Changes between time points were examined with t-test and r-Pearson correlation coefficient was employed to examine correlation between variables at P≤0.05 level of significance. RESULTS: DOTS points in squat increased by 4.6±5.1% (P=0.007) and in total performance increased by 5.2±7.9% (P=0.043). Body mass increased by 2.2±3.7% (P=0.036) and LBM of trunk increased by 3.1±4.7% (P<0.05). No alterations were observed for vastus lateralis muscle architecture after the training period (P > 0.05). DOTS points percentage changes in total performance were highly correlated with percentage changes in total LBM (r=0.73, P=0.011) and legs LBM (r=0.72, P=0.013). DOTS points percentage changes in squat, bench press and deadlift were correlated with percentage changes in body mass (r=0.64 to 0.756, P<0.05). Also, DOTS points changes in squat after the training intervention were significantly associated with changes in quadriceps cross sectional area (r=0.67, P=0.024). CONCLUSION: These results suggest that individual changes in lean body mass due to systematic resistance training toward a competition may predict changes performance in trained powerlifters. Body mass is good predictor for changes in squat, bench press and deadlift performance calculated by DOTS.

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ECSS Paris 2023: OP-AP16

Speaker C Sergio Perez Regalado

Speaker C

Sergio Perez Regalado
University of Granada, Physical Education
Spain
"Synergistic effects of resistance training at moderate altitude on metabolic-related myokines: implications for adipose tissue modulation"

INTRODUCTION: Hypobaric hypoxia (HH) exposure is characterized by an elevation of the sympathetic nervous system that could impact on metabolic-related myokines in human adipocytes, such as interleukin 15 (IL-15), involved mainly in the promotion of lipolysis (1). Additionally, resistance training (RT) programs have been associated with weight loss while preserving muscle mass. However, there are no previous studies undertaken long-term RT regimens under terrestrial HH conditions describing the molecular mechanisms linked to modulation of subcutaneous adipose tissue (SAT) thickness. In this sense, the present study aims to analyse the influence of HH exposure on SAT and circulating IL-15 response after an 8-week RT program. METHODS: Twenty men (22.75±3.73 years; 176.4±5.93 cm; 73.01±10.97 kg) participated in an 8-week program (3 sessions/week) of a traditional hypertrophy training under intermittent terrestrial HH (2320 m) or normoxia (N, 690 m). Seventy-two hours before and after the RT program, vastus lateralis (VL) thickness and SAT were measured by ultrasound (GE-LOGICQ-E portable, UK) and blood samples were taken to analyse serum IL-15 by immunology multiplex assay (Sigma-Aldrich; Darmstadt, Germany). RESULTS: Circulating IL-15 revealed an environmental effect following 8 weeks of RT program (F1,18 = 4.399; p = 0.050; n2p = 0.196). The pairwise comparison test revealed that HH after RT tend to be favour IL-15 increase (ES = 0.890; p = 0.062) compared to N. Moreover, SAT displayed a very large decrease in HH after the RT period (11.56 % vs -17.69 % in N and HH; p < 0.001 [ES = -1.92]) with no remarkable change in VL between conditions (p > 0.05). CONCLUSION: These results evidence the effect of RT in HH on SAT and serum IL-15 with respect to the same training in N. This effect could be attributed to the IL-15 upregulation-induced muscle promotion of the fibber switching to type II and in the overall increase of lean mass ratio by the stress of the HH combined with RT. (2). Surprisingly, VL values were maintained without significant changes between conditions. Nonetheless, this outcome may not represent the entire effect on muscle growth on muscle due to a potential heterogeneous growth of the vastus quadriceps due to the orientation of the feet during squat training (3). Thus, taking all results together, it appears that the stressors factors linked to RT in HH may play a key role in the overall body composition. Further research targeting this potential non-pharmacological approach for adipose regulation is needed to determine the implication on sport performance and control of obesity-related disorders. References 1. Duan Y, et al. 2017; PMID: 28752527. 2. Nielsen AR, et al. 2007; PMID: 17690139. 3. Murray N, Cipriani D, O’RAND D, Reed-Jones R. 2013; PMID: 27293497.

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ECSS Paris 2023: OP-AP16