This post is part of the continuing mini-series on RQ–RH–D–M across fields. Its purpose is to provide a compact, practical toolkit showing how research questions, research hypotheses or working propositions, data, and methodology can be aligned in one specific discipline.

Sport and diet is an especially useful field for this kind of exercise because it naturally combines performance, training load, body composition, recovery, nutrition, behavior, motivation and health outcomes. It also supports quantitative, qualitative and mixed methods designs, making it ideal for showing how the same topic can be studied through physiological measures, behavioral data, lived experience and integrated designs.

In sport research, theoretical foundations often come from sport psychology, achievement goal theory, self-determination theory, motivation theory, training and adaptation models, biomechanical frameworks, performance analysis, talent development models, health behavior theory and, in sport sociology, from frameworks of identity, embodiment and participation. These models define constructs such as motivation, performance, fatigue, confidence, engagement, adaptation, skill acquisition, injury risk or exercise adherence, which are measured through performance tests, physiological indicators, observational coding, questionnaires, training records, interviews or combined sport-science datasets.

Note: The entries in the Methodology are intentionally general and indicative. They are meant to illustrate plausible methodological directions, not to exhaust the full range of possible methods, model variants or analytic choices available to the researcher. Researchers are not expected to apply all of the methodological tools listed in column Methodology in a single study. The entries are intended to indicate suitable methodological options or families of approaches from which the researcher selects those that best fit the research question, hypothesis, data, and design.