Dark-Matter-Induced Nucleon Decay Signals in Mesogenesis.

We introduce and study the first class of signals that can probe the dark matter in mesogenesis, which will be observable at current and upcoming large volume neutrino experiments. The well-motivated mesogenesis scenario for generating the observed matter-antimatter asymmetry necessarily has dark matter charged under the baryon number. Interactions of these particles with nuclei can induce nucleon decay with kinematics differing from spontaneous nucleon decay. We calculate the rate for this process and develop a simulation of the signal that includes important distortions due to nuclear effects. We estimate the sensitivity of DUNE, Super-Kamiokande, Hyper-Kamiokande, and JUNO to this striking signal.

Assessing the Impact of Neuromuscular Electrical Stimulation-Based Fingerboard Training versus Conventional Fingerboard Training on Finger Flexor Endurance in Intermediate to Advanced Sports Climbers: A Randomized Controlled Study.

Competitive climbers engage in highly structured training regimens to achieve peak performance levels, with efficient time management as a critical aspect. Neuromuscular electrical stimulation (NMES) training can close the gap between time-efficient conditioning training and achieving optimal prerequisites for peak climbing-specific performances. Therefore, we examined potential neuromuscular adaptations resulting from the NMFES intervention by analyzing the efficacy of twice-weekly NMES-supported fingerboard (hang board) training compared with thrice-weekly conventional fingerboard training over 7 training weeks in enhancing climbing-specific endurance among intermediate to advanced climbers. Participants were randomly divided into the NMES and control groups. Eighteen participants completed the study (14 male, 4 female; mean age: 25.7 ± 5.3 years; mean climbing experience: 6.4 ± 3.4 years). Endurance was assessed by measuring the maximal time athletes could support their body weight (hanging to exhaustion) on a 20 mm-deep ledge at three intervals: pre-, in-between- (after 4 weeks of training), and post-training (after 7 weeks of training). The findings revealed that despite the lower training volume in the NMES group, no significant differences were observed between the NMES and control groups in climbing-specific endurance. Both groups exhibited notable improvements in endurance, particularly after the in-between test. Consequently, a twice-weekly NMES-supported fingerboard training regimen demonstrated non-inferiority to a thrice-weekly conventional training routine. Incorporating NMES into fingerboard workouts could offer time-saving benefits.

The prescription of psychedelic therapies in Australia and New Zealand: A brief survey of psychiatrists.

OBJECTIVE: To explore the knowledge and attitudes of psychiatrists about psychedelics therapies. METHOD: Access to a cross-sectional survey was distributed to psychiatrists through social media channels. Attitudes and knowledge about psychedelic therapies were recorded using Likert scales and ranking questions. RESULTS: Fifty-eight complete responses were collected (44 fully trained +14 trainee RANZCP members). Greater than 85% of respondents agreed there is a shortfall in effective psychiatric treatments, and greater than 65% agreed that psychedelic therapies might address this shortfall. The psychiatrists did not consider themselves knowledgeable about psychedelic therapies, with 60% showing interest in further training on this topic. About 70% of the sample hold various concerns about psychedelic therapies, and more believe that the prescription of psychedelics should be limited to psychiatrists in the future. CONCLUSION: Considering these results in the context of a rapidly changing landscape relating to psychedelic research and regulations, we suggest there is scope to develop up-to-date education about psychedelics for psychiatrists.

Spatial Distribution of Muscular Effects of Acute Whole-Body Electromyostimulation at the Mid-Thigh and Lower Leg-A Pilot Study Applying Magnetic Resonance Imaging.

Whole-body electromyostimulation (WB-EMS) is an innovative training method that stimulates large areas simultaneously. In order to determine the spatial distribution of WB-EMS with respect to volume involvement and stimulation depth, we determined the extent of intramuscular edema using magnetic resonance imaging (MRI) as a marker of structural effects. Intense WB-EMS first application (20 min, bipolar, 85 Hz, 350 µs) was conducted with eight physically less trained students without previous WB-EMS experience. Transversal T2-weighted MRI was performed at baseline and 72 h post WB-EMS to identify edema at the mid-thigh and lower leg. The depth of the edema ranged from superficial to maximum depth with superficial and deeper muscle groups of the mid-thigh or lower leg area approximately affected in a similar fashion. However, the grade of edema differed between the muscle groups, which suggests that the intensity of EMS-induced muscular contraction was not identical for all muscles. WB-EMS of the muscles via surface cuff electrodes has an effect on deeper parts of the stimulated anatomy. Reviewing the spatial and volume distribution, we observed a heterogeneous pattern of edema. We attribute this finding predominately to different stimulus thresholds of the muscles and differences in the stress resistance of the muscles.

Increasing Top-Down Mass Spectrometry Sequence Coverage by an Order of Magnitude through Optimized Internal Fragment Generation and Assignment.

A major limitation of intact protein fragmentation is the lack of sequence coverage within proteins' interiors. We show that collisionally activated dissociation (CAD) produces extensive internal fragmentation within proteins' interiors that fill the existing gaps in sequence coverage, including disulfide loop regions that cannot be characterized using terminal fragments. A barrier to the adoption of internal fragments is the lack of methods for their generation and assignment. To provide these, we explore the effects of protein size, mass accuracy, internal fragment size, CAD activation energy, and data preprocessing upon the production and identification of internal fragments. We also identify and mitigate the major source of ambiguity in internal fragment identification, which we term "frameshift ambiguity." Such ambiguity results from sequences containing any "middle" portion surrounded by the same composition on both termini, which upon fragmentation can produce two internal fragments of identical mass, yet out of frame by one or more amino acids (e.g., TRAIT producing TRAI or RAIT). We show that such instances permit the a priori assignment of the middle sequence portion. This insight and our optimized methods permit the unambiguous assignment of greater than 97% of internal fragments using only the accurate mass. We show that any remaining ambiguity in internal fragment assignment can be removed by consideration of fragmentation propensities or by (pseudo)-MS3. Applying these methods resulted in a 10-fold and 43-fold expanded number of identified ions, and a concomitant 7- and 16-fold increase in fragmentation sites, respectively, for native and reduced forms of a disease-associated SOD1 variant.

Substantiating synesthesia: a novel aid in a case of grapheme-colour synesthesia and concomitant dyscalculia.

Here we present the case of SP, a 21-year-old female with life-long dyscalculia. SP was subsequently diagnosed with grapheme-color synesthesia, a diagnosis that serendipitously catalyzed our development of a novel aid:The digit-color calculator (DCC). The DCC substantiates SP's color concurrents, dramatically ameliorating her difficulties with basic calculations. We envisage the DCC and its analogues may assist others in educational settings, particularly if they experience difficulties with the acquisition of literacy and numeracy. Further devices that leverage synesthesia may also have the potential to improve the quality of life for others with trait synesthesia regardless of concomitant disorder.

Can A Superimposed Whole-Body Electromyostimulation Intervention Enhance the Effects of a 10-Week Athletic Strength Training in Youth Elite Soccer Players?

Strength training in youth soccer has both a preventive and a sports-specific component. Whole-body electromyostimulation (WB-EMS) could represent an interesting time-saving add-on to classical strength exercises in performance-oriented soccer. The objective of this study was to find out whether a 10-week superimposed WB-EMS training might have a more positive impact on strength parameters in male youth elite soccer players than regular athletic strength exercises alone. A total of 30 male youth soccer players from a youth academy aged 15 to 17 years participated in the study. Before and after the intervention, the isometric extension and flexion forces of trunk and knee, and the hip abduction and adduction forces were tested. Twelve players (control group) absolved a conventional 20-minute strength training once a week for a period of ten weeks. Eighteen players absolved the same exercises but with superimposed WB-EMS. Blood creatine kinase concentration was measured for training control. ANOVAs, Friedman tests and post hoc t-tests were calculated (p = 0.05) to examine the strength development during the training period between the groups. While we could not find significant strength increases in the leg, hip and trunk muscles in the control group (<4%), the strength of the WB-EMS group improved significantly in 4 of the 6 muscle groups tested. In this group, the strength of knee flexors increased significantly by 20.68 ± 21.55%, knee extensors by 31.43 ± 37.02%, hip adductors by 21.70 ± 12.86% and trunk flexors by 33.72 ± 27.43%. The rates of strength increase are partly in line with other studies, partly clearly higher, which might be explained by the athletically active target group. A 10-week superimposed WB-EMS training improves the strength of certain leg, hip and trunk muscles in male adolescent elite soccer players to a greater extent than a pure athletic strength training of the same duration.

Effects of an Impulse Frequency Dependent 10-Week Whole-body Electromyostimulation Training Program on Specific Sport Performance Parameters.

The difference in the efficacy of altered stimulation parameters in whole-body-electromyostimulation (WB-EMS) training remains largely unexplored. However, higher impulse frequencies (>50 Hz) might be most adequate for strength gain. The aim of this study was to analyze potential differences in sports-related performance parameters after a 10-week WB-EMS training with different frequencies. A total of 51 untrained participants (24.9 ± 3.9 years, 174 ± 9 cm, 72.4 ± 16.4 kg, BMI 23.8 ± 4.1, body fat 24.7 ± 8.1 %) was randomly divided into three groups: one inactive control group (CON) and two training groups. They completed a 10-week WB-EMS program of 1.5 sessions/week, equal content but different stimulation frequencies (training with 20 Hz (T20) vs. training with 85 Hz (T85)). Before and after intervention, all participants completed jumping (Counter Movement Jump (CMJ), Squat Jump (SJ), Drop Jump (DJ)), sprinting (5m, 10m, 30m), and strength tests (isometric trunk flexion/extension). One-way ANOVA was applied to calculate parameter changes. Post-hoc least significant difference tests were performed to identify group differences. Significant differences were identified for CMJ (p = 0.007), SJ (p = 0.022), trunk flexion (p = 0.020) and extension (p=.013) with significant group differences between both training groups and CON (not between the two training groups T20 and T85). A 10-week WB-EMS training leads to significant improvements of jump and strength parameters in untrained participants. No differences could be detected between the frequencies. Therefore, both stimulation frequencies can be regarded as adequate for increasing specific sport performance parameters. Further aspects as regeneration or long term effects by the use of different frequencies still need to be clarified.

Whole-body electromyostimulation in physical therapy: do gender, skinfold thickness or body composition influence maximum intensity tolerance?

[Purpose] Whole-body electromyostimulation (WB-EMS) is an extension of the EMS application known in physical therapy. In WB-EMS, body composition and skinfold thickness seem to play a decisive role in influencing the Ohmic resistance and therefore the maximum intensity tolerance. That is why the therapeutic success of (WB-)EMS may depend on individual anatomical parameters. The aim of the study was to find out whether gender, skinfold thickness and parameters of body composition have an influence on the maximum intensity tolerance in WB-EMS. [Participants and Methods] Fifty-two participants were included in the study. Body composition (body impedance, body fat, fat mass, fat-free mass) and skinfold thicknesses were measured and set into relation to the maximum intensity tolerance. [Results] No relationship between the different anthropometric parameters and the maximum intensity tolerance was detected for both genders. Considering the individual muscle groups, no similarities were found in the results. [Conclusion] Body composition or skinfold thickness do not seem to have any influence on the maximum intensity tolerance in WB-EMS training. For the application in physiotherapy this means that a dosage of the electrical voltage within the scope of a (WB-) EMS application is only possible via the subjective feedback (BORG Scale).

Effects of a 6-Week Strength Training of the Neck Flexors and Extensors on the Head Acceleration during Headers in Soccer.

The importance of well trained and stable neck flexors and extensors as well as trunk muscles for intentional headers in soccer is increasingly discussed. The neck flexors and extensors should ensure a coupling of trunk and head at the time of ball contact to increase the physical mass hitting the ball and reduce head acceleration. The aim of the study was to analyze the influence of a 6-week strength training program (neck flexors, neck extensors) on the acceleration of the head during standing, jumping and running headers as well as after fatigue of the trunk muscles on a pendulum header. A total of 33 active male soccer players (20.3 ± 3.6 years, 1.81 ± 0.07 m, 75.5 ± 8.3 kg) participated and formed two training intervention groups (IG1: independent adult team, IG2: independent youth team) and one control group (CG: players from different teams). The training intervention consisted of three exercises for the neck flexors and extensors. The training effects were verified by means of the isometric maximum voluntary contraction (IMVC) measured by a telemetric Noraxon DTS force sensor. The head acceleration during ball contact was determined using a telemetric Noraxon DTS 3D accelerometer. There was no significant change of the IMVC over time between the groups (F=2.265, p=.121). Head acceleration was not reduced significantly for standing (IG1 0.4 ± 2.0, IG2 0.1 ± 1.4, CG -0.4 ± 1.2; F = 0.796, p = 0.460), jumping (IG1-0.7 ± 1.4, IG2-0.2 ± 0.9, CG 0.1 ± 1.2; F = 1.272, p = 0.295) and running (IG1-1.0 ± 1.9, IG2-0.2 ± 1.4, CG -0.1 ± 1.6; F = 1.050, p = 0.362) headers as well as after fatigue of the trunk musculature for post-jumping (IG1-0.2 ± 2.1, IG2-0.6 ± 1.4; CG -0.6 ± 1.3; F = 0.184, p = 0.833) and post-running (IG1-0.3 ± 1.6, IG2-0.7 ± 1.2, CG 0.0 ± 1.4; F = 0.695, p = 0.507) headers over time between IG1, IG2 and CG. A 6-week strength training of the neck flexors and neck extensors could not show the presumed preventive benefit. Both the effects of a training intervention and the consequences of an effective intervention for the acceleration of the head while heading seem to be more complex than previously assumed and presumably only come into effect in case of strong impacts.

The mental health of male victims and their children affected by legal and administrative partner aggression.

The authors recently developed a psychometrically valid measure of legal and administrative (LA) intimate partner violence (IPV) victimization (Hines, Douglas, & Berger, 2014). The current article explores the impact of actual and threatened LA aggression on the mental health of male physical IPV victims and their children. In the current study, a sample of 611 men who sought help after experiencing physical IPV from their female partners completed a survey assessing the types and extent of IPV that occurred in their relationship, including LA aggression, their own mental health outcomes, and the mental health of their oldest child. A series of OLS regressions indicated that after controlling for covariates, actual LA aggression was associated with more symptoms of PTSD and depression in male victims, and that both threatened and actual LA aggression were associated with higher levels of affective and oppositional defiant symptoms in the men's school age children. The current findings suggest that it is important to screen couples for the presence of LA aggression and male partners and their children should be referred for mental health treatment if LA aggression is occurring in the relationship. Aggr. Behav. 42:346-361, 2016. © 2015 Wiley Periodicals, Inc.

A self-report measure of legal and administrative aggression within intimate relationships.

Although experts agree that intimate partner violence (IPV) is a multidimensional phenomenon comprised of both physical and non-physical acts, there is no measure of legal and administrative (LA) forms of IPV. LA aggression is when one partner manipulates the legal and other administrative systems to the detriment of his/her partner. Our measure was developed using the qualitative literature on male IPV victims' experiences. We tested the reliability and validity of our LA aggression measure on two samples of men: 611 men who sustained IPV and sought help, and 1,601 men in a population-based sample. Construct validity of the victimization scale was supported through factor analyses, correlations with other forms of IPV victimization, and comparisons of the rates of LA aggression between the two samples; reliability was established through Cronbach's alpha. Evidence for the validity and reliability of the perpetration scale was mixed and therefore needs further analyses and revisions before we can recommend its use in empirical work. There is initial support for the victimization scale as a valid and reliable measure of LA aggression victimization among men, but work is needed using women's victimization's experiences to establish reliability and validity of this measure for women. An LA aggression measure should be developed using LGBTQ victims' experiences, and for couples who are well into the divorce and child custody legal process. Legal personnel and practitioners should be educated on this form of IPV so that they can appropriately work with clients who have been victimized or perpetrate LA aggression.

A Pilot Trial of Gender-Based Motivational Interviewing for Help-Seeking and Internalizing Symptoms in Men.

There has been limited research on interventions addressing the psychosocial barriers to men's underutilization of formal and informal help. To address this gap in the literature, we report on the development of Gender-Based Motivational Interviewing (GBMI) for men with internalizing symptoms and present the findings of a pilot trial. GBMI is a single session of assessment and feedback that integrates gender-based and motivational interviewing principles. Community-dwelling men (N = 23) with elevated internalizing symptoms and no recent history of formal help-seeking were randomized to either GBMI or control conditions and were followed for three months. The effect of GBMI on internalizing and externalizing symptoms ranged from small to large across follow-ups. GBMI had a small to moderate effect on stigma. There was no effect on help-seeking attitudes or intentions. GBMI increased use of informal help seeking (e.g. parents and partners) and had no effect on formal help seeking. None of these findings were statistically significant. Study weaknesses included baseline differences in help-seeking variables between conditions. This initial evaluation suggested that GBMI shows promise for improving mental health functioning while further research is need to determine its effect on help-seeking.

Position statement and updated international guideline for safe and effective whole-body electromyostimulation training-the need for common sense in WB-EMS application.

Whole-Body Electromyostimulation (WB-EMS) is a training technology that enables simultaneous stimulation of all the main muscle groups with a specific impulse intensity for each electrode. The corresponding time-efficiency and joint-friendliness of WB-EMS may be particularly attractive for people unable or unmotivated to conduct (intense) conventional training protocols. However, due to the enormous metabolic and musculoskeletal impact of WB-EMS, particular attention must be paid to the application of this technology. In the past, several scientific and newspaper articles reported severe adverse effects of WB-EMS. To increase the safety of commercial non-medical WB-EMS application, recommendations "for safe and effective whole-body electromyostimulation" were launched in 2016. However, new developments and trends require an update of these recommendations to incorporate more international expertise with demonstrated experience in the application of WB-EMS. The new version of these consensus-based recommendations has been structured into 1) "general aspects of WB-EMS", 2) "preparation for training", recommendations for the 3) "WB-EMS application" itself and 4) "safety aspects during and after training". Key topics particularly addressed are 1) consistent and close supervision of WB-EMS application, 2) mandatory qualification of WB-EMS trainers, 3) anamnesis and corresponding consideration of contraindications prior to WB-EMS, 4) the participant's proper preparation for the session, 5) careful preparation of the WB-EMS novice, 6) appropriate regeneration periods between WB-EMS sessions and 7) continuous interaction between trainer and participant at a close physical distance. In summary, we are convinced that the present guideline will contribute to greater safety and effectiveness in the area of non-medical commercial WB-EMS application.

Corrigendum: Position statement and updated international guideline for safe and effective whole-body electromyostimulation training-the need for common sense in WB-EMS application.

[This corrects the article DOI: 10.3389/fphys.2023.1174103.].

WB-EMS Market Development-Perspectives and Threats.

As a time-efficient and highly effective form of training, whole-body electromyostimulation (WB-EMS) enables personalised training for a wide range of users due to its personal training character and the individual control of the training intensity. However, due to misuse, negative side effects of WB-EMS have been reported in the past, resulting in expert guidelines for safe and effective WB-EMS application being issued. Furthermore, the use of WB-EMS is now legally permitted only for qualified personnel with certified equipment. This professionalization of the WB-EMS market as per the definition of quality standards for the devices and the personnel ensured a safe and effective WB-EMS application. However, recent market developments are undermining these standards through the growing of WB-EMS offers for the private sector. Hereby, most concepts focus on completely or predominately non-supervised WB application without control of potential overload by a qualified trainer. WB application is by no means trivial and the shift of responsibility for safety and effectiveness from the certified personnel to the trainees themselves is a clear step backwards in the development of WB-EMS use. We conclude that private, inadequately supervised WB-EMS application bears more dangers than potential benefits, not only for the trainees but also for the WB-EMS market as a whole.

Heading in Soccer: Does Kinematics of the Head-Neck-Torso Alignment Influence Head Acceleration?

There is little scientific evidence regarding the cumulative effect of purposeful heading. The head-neck-torso alignment is considered to be of great importance when it comes to minimizing potential risks when heading. Therefore, this study determined the relationship between head-neck-torso alignment (cervical spine, head, thoracic spine) and the acceleration of the head, the relationship between head acceleration and maximum ball speed after head impact and differences between head accelerations throughout different heading approaches (standing, jumping, running). A total of 60 male soccer players (18.9 ± 4.0 years, 177.6 ± 14.9 cm, 73.1 ± 8.6 kg) participated in the study. Head accelerations were measured by a telemetric Noraxon DTS 3D Sensor, whereas angles for the head-neck-torso alignment and ball speed were analyzed with a Qualisys Track Manager program. No relationship at all was found for the standing, jumping and running approaches. Concerning the relationship between head acceleration and maximum ball speed after head impact only for the standing header a significant result was calculated (p = 0.024, R2 = .085). A significant difference in head acceleration (p < .001) was identified between standing, jumping and running headers. To sum up, the relationship between head acceleration and head-neck-torso alignment is more complex than initially assumed and could not be proven in this study. Furthermore first data were generated to check whether the acceleration of the head is a predictor for the resulting maximum ball speed after head impact, but further investigations have to follow. Lastly, we confirmed the results that the head acceleration differs with the approach.

Sharing the load: How a personally coloured calculator for grapheme-colour synaesthetes can reduce processing costs.

Synaesthesia refers to a diverse group of perceptions. These unusual perceptions are defined by the experience of concurrents; these are conscious experiences that are catalysed by attention to some normally unrelated stimulus, the inducer. In grapheme-colour synaesthesia numbers, letters, and words can all cause colour concurrents, and these are independent of the actual colour with which the graphemes are displayed. For example, when seeing the numeral '3' a person with synaesthesia might experience green as the concurrent irrespective of whether the numeral is printed in blue, black, or red. As a trait, synaesthesia has the potential to cause both positive and negative effects. However, regardless of the end effect, synaesthesia incurs an initial cost when compared with its equivalent example from normal perception; this is the additional processing cost needed to generate the information on the concurrent. We contend that this cost can be reduced by mirroring the concurrent in the environment. We designed the Digital-Colour Calculator (DCC) app, allowing each user to personalise and select the colours with which it displays its digits; it is the first reported example of a device/approach that leverages the concurrent. In this article we report on the reactions to the DCC for a sample of fifty-three synaesthetes and thirty-five non-synaesthetes. The synaesthetes showed a strong preference for the DCC over its normal counterpart. The non-synaesthetes showed no obvious preference. When using the DCC a subsample of the synaesthete group showed consistent improvement in task speed (around 8%) whereas no synaesthete showed a decrement in their speed.

Efficacy of Whole-Body Electromyostimulation (WB-EMS) on Body Composition and Muscle Strength in Non-athletic Adults. A Systematic Review and Meta-Analysis.

This systematic review and meta-analysis set out to determine the efficacy on whole-body electromyostimulation (WB-EMS) on body composition and strength parameters in non-athletic cohorts. A systematic review of the literature according to the PRISMA statement included (a) controlled trials, (b) WB-EMS trials with at least one exercise and one control group, (c) WB-EMS as primary physical intervention, (d) WB-EMS with at least six electrodes covering most muscle groups, (e) non-athletic cohorts. We searched eight electronic databases up to June 30, 2020, without language restrictions. Standardized mean differences (SMD) for muscle mass parameters, total body fat mass, maximum leg extension, and trunk extension strength were defined as outcome measures. In summary, 16 studies with 19 individual WB-EMS groups representing 897 participants were included. Studies vary considerably with respect to age, BMI, and physical conditions. Impulse protocols of the studies were roughly comparable, but training frequency (1-5 sessions/week) and intervention length (6-54 weeks) differed between the studies. SMD average was 1.23 (95%-CI: 0.71-1.76) for muscle mass, 0.98 (0.74-1.22) for maximum leg, and 1.08 (0.78-1.39) for maximum trunk extension strength changes (all p < 0.001). SMD for body fat changes (-0.40, [-0.98 to 0.17]), however, did not reach significance. I 2 and Q-statistics revealed substantial heterogeneity of muscle and fat mass changes between the trials. However, rank and regression tests did not indicate positive evidence for small-study bias and funnel plot asymmetries. This work provided further evidence for significant, large-sized effects of WB-EMS on muscle mass and strength parameters, but not on body fat mass. Clinical Trial Registration: ClinicalTrials.gov, PROSPERO; ID: CRD42020183059.

Frequency-Dependent Reaction of the Triceps Surae Muscle of the Mouse During Electromyostimulation.

The difference in the efficacy of altered stimulation parameters in whole-body-electromyostimulation training (WB-EMS) has hardly been examined. Higher impulse frequencies (>50 Hz) might be most adequate for strength gains because of the force frequency relationship (FFR), which describes a greater force production by increasing the applied frequency. Frequencies below this value, however, also seem to have positive influences on muscle strength increases. Therefore, the aim of this study was to analyze possible muscle length changes to different stimulation frequencies of the dissected mouse triceps surae muscle. A bending rod transducer was used to measure and compare changes in muscle lengths at different frequencies in relation to the initial length in the prepared muscle. We found significant differences between the muscle shortening at different frequencies (p < 0.001). At 20 Hz the largest muscle shortening was observed (20 Hz = 3.32 ± 2.06, 60 Hz = 0.77 ± 0.58, 85 Hz = 0.32 ± 0.29, 100 Hz = 0.31 ± 0.29). From a frequency of 60 Hz, the muscle shortening decreased progressively, at stimulation frequencies above 60 Hz the lowest shortenings were recorded. The results demonstrate a different behavior of the isolated triceps surae muscle of the mouse in an ex vivo environment. Even if there is no FFR in this investigation, the results indicate a higher metabolic demand using higher frequencies in electromyostimulation, despite the experimental execution in ex vivo design. Therefore, future studies should take this faster fatigue into account when drawing up training protocols in order to counteract possible frequency modulations.