Pedro Morouço

Despite major advances in exercise physiology, biomechanics, and mechanobiology, exercise science still lacks a clear conceptual definition of the mechanical stimulus experienced by skeletal muscle during resistance training. Current approaches rely on diverse external, internal, and biomechanical variables (e.g., volume-load, force, power, velocity, time under tension, or muscle architecture), yet none individually captures the muscle-specific mechanical exposure relevant to muscular adaptation. This conceptual inconsistency limits comparisons across studies, complicates training prescription, and hinders the development of individualized monitoring strategies. This integrative review critically synthesizes current evidence from mechanobiology, skeletal muscle physiology, biomechanics, and resistance training to examine how mechanical stimuli are currently conceptualized, quantified, and interpreted. Based on this synthesis, we propose a working definition of Mechanical Dose as the cumulative, muscle-specific mechanical exposure experienced over a defined time window, characterized by loading magnitude, rate, duration, frequency, and spatial distribution, and conditioned by contraction mode and muscle–tendon geometry. Rather than representing a directly measurable variable, mechanical dose is presented as a latent conceptual construct that can only be estimated through combinations of biomechanical, physiological, and morphological indicators. Building upon this definition, we introduce an integrative conceptual framework linking external load, movement biomechanics, mechanical dose, mechanotransduction, and tissue adaptation. We further discuss how this framework may guide future research on the interpretation of field-based monitoring, resistance training prescription, recovery management, and future explainable artificial intelligence approaches in sport science. By reframing mechanical dose as the central construct connecting biomechanics and biological adaptation, this review provides a unified conceptual basis for future research and contributes toward a more biologically informed paradigm of exercise prescription and monitoring.

It asks how motivational processes are activated, translated into behaviour, disrupted by constraints and reorganized as individuals and contexts change.Several contributions show that motivation is not always associated with physical activity directly.Instead, part of this association may be accounted for by proximal mechanisms that determine whether intention can be enacted. Among Chinese college students, Sheng et al. found that a broad measure of internal exercise motivation was directly associated with physical activity and also indirectly associated through exercise self-efficacy, whereas motivation linked to institutional requirements showed no direct association once self-efficacy was considered. Pan et al. similarly identified exercise self-efficacy as a mediator between physical activity motivation and activity level in medical students, while kinesiophobia weakened the remaining direct association between motivation and activity. Li et al. extended this logic into young adulthood by showing that satisfaction of basic psychological needs in physical education was associated with concurrent exercise behaviour through self-efficacy, with gender functioning as a boundary condition. These studies converge on a simple but important proposition: wanting to move and believing one can move are related but non-interchangeable processes.The same distinction appears in work on more enduring psychological resources. Chen et al. combined variable-centred and person-centred analyses, finding that self-efficacy partly accounted for the association between grit and physical activity, demonstrating the value of studying both average associations and motivational profiles. Outdoor recreation research by Yılmaz likewise positioned selfefficacy as a central resource for campers, illustrating that perceived capability is relevant not only to prescribed exercise but also to voluntary participation in uncertain natural environments. In physically active women, Kabak et al. linked physical activity self-worth with body appreciation through psychological resilience, indicating that positive psychological resources may support a more favourable embodied self-concept rather than merely increasing activity volume.A second set of studies shows that motivation can also operate through identity and social confidence. Jin et al. reported that exercise identity was associated with college students' perceived social self-efficacy through a chain of mediating processes. This finding shifts attention from "doing exercise" to "being an exerciser": repeated participation may acquire self-defining meaning, which can then support confidence in social situations. In ultimate frisbee participants, Tian et al. found that leisure motivation was associated with continuous participation intention through leisure involvement and information acquisition. Sustained participation, in this view, develops as individuals invest attention, knowledge and personal significance in an activity.Taken together, these contributions argue against models in which motivation is treated as a single upstream predictor. Motivation is better understood as a pathway involving perceived competence, efficacy, identity, involvement and interpretation. The practical implication is equally clear. Interventions that attempt to persuade people that exercise is beneficial may fail when they do not also create mastery experiences, realistic progression, meaningful choice and evidence that action is feasible.The collection also demonstrates that motivation is socially produced. Jiang et al. showed that peer support was associated with college students' physical exercise through control beliefs and subjective experience, while intrinsic value moderated several later links in this process. Song and Yang similarly linked students' perceived campus sport environment to physical fitness through peer support and perceived physical literacy. These findings position the social and material environment not as background scenery but as an active component of motivational development. A supportive environment can make activity visible, normal and accessible; it can also provide feedback through which individuals reinterpret their own competence.At an earlier stage of life, Zheng et al. identified an association between parental support and communityresource use for physical activity with fundamental movement skills in children. This is especially important because motivational adaptation begins before individuals can articulate formal exercise goals.Children who receive support and access to community activity resources are more likely to acquire both the skills and the confidence from which later motivation can develop. Çifçi and Demir broadened this perspective through a socio-ecological analysis of Turkish school-aged adolescents, integrating personal and psychological characteristics with social and environmental factors. Their work reinforces the need to avoid attributing inactivity solely to insufficient willpower when behaviour is nested within families, schools, neighbourhoods and cultural expectations.The role of institutional environments is more ambiguous. Formal requirements can initiate participation, but their capacity to sustain it depends on internalization. The contrast observed by Sheng et al. between intrinsic and institutional motivation suggests that compulsory structures are most productive when they build self-efficacy rather than merely enforce attendance. Xiang's study of university students adds an important educational pathway: perceived physical literacy was positively associated with subjective wellbeing both directly and indirectly through autonomous sport motivation. Physical education may therefore become motivationally consequential when it equips students to understand, value and take responsibility for movement, rather than simply requiring temporary compliance.Social influence also operates through enjoyment...

Digital interventions can increase the reach and continuity of physical activity promotion, but evidence remains fragmented across mental health and addictive behaviors. We conducted a comprehensive integrative review supported by structured searches (2015–2026) in biomedical, psychological, multidisciplinary and technology-oriented databases, complemented by backward/forward snowballing. Eligible studies included digital interventions in which physical activity (or sedentary reduction) was a core component and those that reported mental health outcomes (e.g., depression, anxiety, stress, and well-being) and/or addiction-related outcomes (e.g., craving, consumption, lapses/relapse, and treatment retention). We synthesized findings thematically by intervention typology (apps, wearables, hybrid models with human support, and adaptive approaches) and by key active ingredients (goal setting, self-monitoring, feedback, reinforcement, planning, and engagement strategies). Overall, most studies targeted mental health outcomes and used app-based multicomponent programs, sometimes complemented by wearables, with generally short follow-up and heterogeneous engagement metrics. Evidence in addictions was more context-specific and concentrated in alcohol treatment and opioid agonist therapy settings, supporting feasibility and a plausible role for physical activity as a coping strategy. Advanced personalization frameworks (EMA/EMI/JITAI) provide a clear implementation pathway but are less consistently operationalized when physical activity is the central therapeutic component. This review highlights practical design recommendations and research priorities for scalable, safe, and equity-oriented digital physical activity interventions in mental health promotion and relapse prevention.

(1) Background: Gait analysis technologies have advanced; however, traditional systems like optical motion capture are lab-bound and costly, limiting rehabilitation monitoring. This cross-sectional study evaluates self-powered triboelectric nanogenerator (TENG) insoles combined with IMU sensors to assess gait asymmetry, plantar pressure signatures, age effects and injury history in rehabilitation patients, aiming to enable portable, battery-free phenotyping. (2) Methods: Fifty-three patients (22 females, 31 males; age, 29 ± 26 years) from Astana clinics with trauma histories (e.g., spine, ankle, fractures) and 10 healthy references underwent a 2 min walk test (2MWT). TENG insoles captured plantar loading; ankle/knee IMUs measured spatiotemporal parameters (cadence, asymmetry). The data were normalized; the analyses used an ANOVA and correlations (Python 3.14.3). (3) Results: The TENG sensors showed force/frequency linearity (up to 10 V at 20 N). The cadence averaged 101 ± 10 steps/min, declining with age (r = −0.31, p = 0.03) and fractures (r = −0.23, p = 0.04). The asymmetry varied (−54% to +31%) without category differences. Flatfoot (55%) was linked to lateral loading shifts; condition-specific waveform signatures emerged (e.g., lateral heel in ankle issues). (4) TENG-IMU systems feasibly capture gait phenotypes in heterogeneous cohorts, supporting out-of-lab monitoring for personalized rehabilitation without batteries. Prospective validation is required for further practical implications.

Digital interventions can increase reach and continuity of physical activity promotion, but evidence remains fragmented across mental health and addictive behaviors. We conducted a comprehensive integrative review supported by structured searches (2015–2026) in biomedical, psychological, multidisciplinary and technology-oriented databases, complemented by backward/forward snowballing. Eligible studies included digital interventions in which physical activity (or sedentary reduction) was a core component and that reported mental health outcomes (e.g., depression, anxiety, stress, well-being) and/or addiction-related outcomes (e.g., craving, consumption, lapses/relapse, treatment retention). We synthesized findings thematically by intervention typology (apps, wearables, hybrid models with human support, and adaptive approaches) and by key active ingredients (goal setting, self-monitoring, feedback, reinforcement, planning, and engagement strategies). Overall, most studies targeted mental health outcomes and used app-based multicomponent programs, sometimes complemented by wearables, with generally short follow-up and heterogeneous engagement metrics. Evidence in addictions was more context-specific and concentrated in alcohol treatment and opioid agonist therapy settings, supporting feasibility and a plausible role for physical activity as a coping strategy. Advanced personalization frameworks (EMA/EMI/JITAI) provide a clear implementation pathway, but are less consistently operationalized when physical activity is the central therapeutic component. This review highlights practical design recommendations and research priorities for scalable, safe, and equity-oriented digital physical activity interventions in mental health promotion and relapse prevention.

Optimizing sports performance implies precisely balancing the training load applied and the adaptability of biological tissues. Recent advances in mechanobiology have clarified how cells and tissues respond to mechanical stimuli, offering a solid foundation for anchoring prescription, progression, and recovery decisions. However, there is still a gap between this fundamental knowledge and everyday training. In this review, we synthesize central principles of mechanotransduction and tissue remodeling, and propose the operative concept of tissue dose as an axis for tissue load management: the mechanical stimulus effectively felt by muscles, tendons, ligaments, and bone. Applications in strength, speed and power training are discussed, stressing the importance of field metrics (e.g., contact times, force development rates, muscle-tendon stiffness) to estimate dose and adjust interventions in a timely manner. Injury prevention strategies based on the identification of risk windows, monitoring of early signs and tissue-oriented reconditioning protocols are also addressed. Finally, future perspectives are explored, including higher-fidelity wearables and interpretable analytics for custom load-response models. Together, these elements support a paradigm of tissue-oriented training, capable of enhancing performance and reducing the incidence of injuries, reconciling scientific rigor with practical applicability.

Background: The integration of advanced 3D scanning and additive manufacturing technologies in stroke rehabilitation offers promising advancements in the design and production of ankle-foot orthoses. These technological innovations are progressively recognized for their potential to provide more precise and customized orthotic solutions for individuals with stroke-related impairments. Objectives: The primary aim of this study was to biomechanically test and validate the effectiveness of custom ankle-foot orthoses produced through additive manufacturing technology using data captured by a novel photogrammetric scanning system. The customized orthosis was compared with a standard prefabricated orthosis to assess their relative effectiveness in improving gait dynamics and patient satisfaction in stroke rehabilitation. Methods: Participants with equinovarus deformity, a common consequence of stroke, were fitted with custom ankle-foot orthoses, alongside conventional prefabricated orthoses. The study utilized the Qualisys^® motion analysis system for comprehensive biomechanical gait analysis, and the QUEST questionnaire was employed to capture participant feedback on both types of orthoses. Detailed comparisons of gait dynamics were conducted using Statistical Parametric Mapping with each orthosis. Results: The study revealed notable kinematic and kinetic differences between the custom and prefabricated orthoses. The custom orthoses demonstrated superior performance in enhancing gait efficiency, symmetry, and safety. Patient feedback favored the customized orthoses over the prefabricated variants, with higher scores in comfort, fit, and overall effectiveness. Conclusions: This research underscores the effectiveness of custom orthoses produced through additive manufacturing technology for stroke rehabilitation. By offering a comprehensive evaluation of orthotic interventions and establishing a comparative framework, the study serves as a reference point for future research, advocating for a more personalized and evidence-based approach in orthotic design for improving the quality of life of stroke survivors.

The practice of regular physical activity is widely recognized as one of the main pillars of health throughout the life cycle. Despite the robust evidence supporting its benefits (e.g., in the prevention of chronic diseases, in the improvement of mental health, in the promotion of well-being and longevity) a significant part of the population still does not comply with the minimum recommendations for physical activity. This paradox between knowledge and action has motivated increasing attention from the international scientific community, seeking to understand the psychological and behavioural mechanisms that influence, facilitate or inhibit the regular practice of physical activity and sports participation.It was in this context that this Research Topic was born, jointly hosted by the journals Frontiers in Psychology and Frontiers in Sport and Active Living, with the aim of aggregating scientific contributions that explore the psychological and behavioural dimensions of the practice of physical activity and involvement in sport, at different ages, cultures, contexts and modalities. The set of twenty articles gathered in this special issue constitutes a valuable repository of empirical data, theoretical reflections and proposals for concrete intervention applicability. This editorial thus aims to present a critical synthesis of the main emerging themes, articulate individual contributions in an integrated narrative and highlight the implications for research, practice and public policy formulation. The methodological and geographical diversity of the studies presented allows us to observe more clearly the complexity of this phenomenon and the way in which different variables interact, reinforce or limit the active involvement of people throughout the various stages of life. Contributions range from psychometric analyses to qualitative investigations, from clinical trials to systematic reviews, offering a comprehensive and interdisciplinary panorama.Motivation continues to be one of the most studied axes in the field of physical activity, with approaches ranging from classical theories (e.g. self-determination, planned behaviour) to more recent perspectives, focused on hope, grit or athletic identity.Kovács analyses motivational profiles of more than a thousand young Hungarian athletes, highlighting the complexity of the interactions between sports orientation, persistence and personality traits. The study by Tokarska and Rogowska, used a person-centred approach to identify distinct motivational profiles in cyclists and runners. The authors revealed that different combinations of intrinsic and extrinsic motivation, as well as levels of selfefficacy, configure typologies that directly impact the behaviour of athletes. This differentiated vision allows for the design of intervention strategies that are more adjusted to the reality of each practitioner. The contribution of Ronca et al. broadens this reflection suggesting that personality traits (such as extraversion or emotional stability) can influence not only the preference for certain intensities of physical exercise, but also the magnitude of stress reduction obtained after a training program. This work highlights the importance of individualizing activity proposals, considering psychological predispositions. In the sphere of self-regulation, Blythe et al. demonstrate that hope agency predicts the ability to achieve exercise goals in college students. Participants with higher levels of hope showed greater consistency and success in achieving the set physical goals, pointing to the relevance of positive, future-oriented motivational states. Finally, Zhou et al. present a meta-analysis that reveals a moderate and bidirectional association between exercise motivation and cardiorespiratory fitness in students, consolidating the evidence of the importance of motivation for physical development and vice versa.The role of self-efficacy as a behavioural determinant is evidenced in several studies in this collection. The meta-analysis by Xie et al. demonstrates a consistent association between self-efficacy and physical activity in older adults, with a mutually reinforcing relationship. This virtuous cycle is especially relevant for the design of interventions aimed at active aging. The relevance of this construct also extends to other age groups, as evidenced by Kessler et al., who studied middle-aged and older adults with musculoskeletal pain. The work revealed that hope (understood as an emotional component related to self-efficacy) significantly predicts the levels of physical activity reported, even in the face of physical limitations. This finding reinforces the idea that positive psychological aspects can mitigate physical barriers and motivate active behaviour. On the other hand, Na et al. contributed to the development and preliminary validation of a scale of parenting practices promoting physical activity for Chinese children between 3 and 6 years old. The application of this instrument revealed the significant influence of parenting styles on children's self-efficacy beliefs regarding movement and structured play practice, highlighting the importance of facilitating contexts from early childhood. Still in the field of the relationship between exercise and mental health, Zhang et al. demonstrated that regular physical activity in Chinese university students significantly improves emotional management, and this effect is mediated by two factors: life satisfaction and perceived health. These results point to psychological mediation mechanisms with potential for interventions in academic environments. Still in the field of the relationship between exercise and mental health, the study by Ahsan et al. analysed the effects of physical activity on mental toughness and quality of life in a gender-differentiated sample of young adults. The authors identified differences between men and women in physical activity levels, as well as in...