Ryan Rhodes

Ryan Rhodes

Ryan E. Rhodes is Professor in the School of Exercise Science, Physical and Health Education at the University of Victoria and Director of the Behavioural Medicine Laboratory, which he founded there in 2004. He is the first author of Rhodes, Kaushal and Quinlan (2016), the meta-analysis putting the relationship between identity and physical activity at r = .44, and of Rhodes and Kates (2015), which found that how a session feels during exercise predicts future activity while how it feels afterwards does not. Two of his reviews carry most of the weight in this publication's account of exercise adherence.

Who they are

Rhodes is cross-listed in the Department of Psychology at Victoria, and his field is the psychology of physical activity and sedentary behaviour, with a particular focus on the intention-behaviour gap: why people who mean to exercise often do not, and what turns an intention into an action. His team developed the multi-process action control framework. He was named a Highly Cited Researcher by Clarivate in 2024.

He wrote the meta-analysis, not the original construct. Exercise identity is Deborah Kendzierski's, from 1988 and 1990, and the measurement instrument is Anderson and Cychosz's, from 1994. That chain of credit is stated here because popular writing collapses it and attributes the whole idea to trade books published decades later.

Key papers

Rhodes, R. E., Kaushal, N., & Quinlan, A. (2016). "Is physical activity a part of who I am? A review and meta-analysis of identity, schema and physical activity", Health Psychology Review, 10(2), 204 to 225. First author. Across role identity and self-schema measures, r = .44 with physical activity participation, random effects, 95 per cent CI .39 to .48, which is the figure in the paper's abstract. The fixed-effects estimate on the same data is r = .40. Corrected 11 September 2026, when this page printed .40 as the headline and article 10 printed .44.

Rhodes, R. E., & Kates, A. (2015). "Can the affective response to exercise predict future motives and physical activity behaviour? A systematic review of published evidence", Annals of Behavioral Medicine, 49(5), 715 to 731. A systematic review of 24 studies. A positive change in affect during moderate-intensity exercise predicted future physical activity. Post-exercise affect had a null relationship with behaviour.

Key ideas

Identity is among the most reliable correlates of physical activity in the whole literature, at a medium effect size, and it is correlational. Identity and behaviour reinforce each other, and a meta-analysis of the relationship cannot say which moves first.

The affect finding is the sharpest correction in this cluster and it goes almost unquoted. How you feel during the session predicts whether you come back. How you feel afterwards does not. That is bad news for every plan built on the idea that you will not regret it once it is done, and it is a direct argument against going too hard in week one.

The intention-behaviour gap is the organising problem: intending to exercise and exercising are separated by failures that can be specified and therefore targeted.

Credit for exercise identity runs Kendzierski, then Anderson and Cychosz, then Rhodes and colleagues. Not the other way round.

Concepts on this site

Exercise Identity, where his meta-analysis sits

Exercise Adherence, where both his reviews do work

Implementation Intentions, the standard answer to the intention-behaviour gap he studies

Flow State, adjacent, on how a session feels while it is happening

Sources

  1. Rhodes, R. E., Kaushal, N., & Quinlan, A. (2016). Health Psychology Review, 10(2), 204 to 225.
  2. Rhodes, R. E., & Kates, A. (2015). Annals of Behavioral Medicine, 49(5), 715 to 731.
  3. Kendzierski, D. (1988, 1990) and Anderson, D. F., & Cychosz, C. M. (1994). The originating construct and the measurement instrument.
  4. Vault verification record, 2026-09-11. r = .44 confirmed against the full text as the figure to print, correcting an earlier entry the same day that named .40. The chain of credit is recorded, and every estimate the paper reports is set out on the exercise identity page.