Background <p>This scoping review aimed to identify how Ecological Momentary Assessment methodologies using mobile health technologies are applied to monitor training load and the stress-recovery process in athletes. The review focused on mapping the technologies and methodologies employed, examining their use in team and individual sports, and exploring the relationships between external and internal load measures, as well as the extent to which subjective and objective indicators are integrated within monitoring systems.</p> Method <p>Following PRISMA-ScR guidelines, a systematic search across four databases identified 71 studies published between 2012 and 2025 that met eligibility criteria.</p> Results <p>Half of studies focused on elite or international athletes (50.68%), with a predominance of male participants (63.4%). Team sports represented the vast majority (87.3%), particularly soccer (42.5%) and basketball (15.1%). A wide range of technologies was reported, from advanced wearable systems to smartphone applications, with external load commonly tracked via GPS and accelerometry, and internal load through heart rate indices, Training Impulse, Rating of Perceived Exertion, and wellness questionnaires. However, only seven studies directly compared subjective and objective measures of internal load, revealing partial convergence and underscoring the value of multimodal monitoring strategies.</p> Conclusions <p>Ecological Momentary Assessment-based mobile health systems provide valuable insights into athlete load and recovery, but important gaps remain in individual sports, female representation, and recovery-related behaviors. Future research should prioritize methodological transparency, broader inclusion of populations, and the adoption of emerging non-invasive biosensing technologies to achieve a more holistic and ecologically valid model of athlete monitoring.</p>