Dr Janet Withall PhD

Dr Janet Withall

School of Sport, Exercise and Rehabilitation Sciences
ACE Trial Manager

Contact details

School of Sport, Exercise and Rehabilitation Sciences
University of Birmingham
B15 2TT

Dr Janet Withall is an experienced researcher in the field of the promotion of active and healthy ageing.  She currently manages the NIHR funded ACE randomized controlled trial investigating ways of supporting older people achieving meaningful and lasting lifestyle changes and living healthier and fulfilling lives.


  • PhD Exercise and Health Science. University of Bristol, U.K.
  • MSc Exercise, Nutrition and Health Sciences. University of Bristol, U.K.
  • BSc in Business Studies. University of Bradford, U.K.


Dr Janet Withall joined the School of Sport, Exercise and Rehabilitation Sciences at the University of Birmingham in September 2021. Previously, she worked for 7 years at the University of Bath. She completed her postgraduate studies at the University of Bristol (MSc and PhD).


Dr Withall has a sustained track record in the field of active ageing and public health.  

Her research interests focus on two inter-related themes: 

1) Exploring relationships between physical activity, mobility and well-being;

2) Developing and evaluating lifestyle interventions targeting older adults.

Other activities

Previous posts;  

  1. University of Bath – Trial Manager for the REACT (Retirement in Action) study
  2. University of Bath – Senior researcher on the ACE (Active Connected Engaged) feasibility study


  1. Stathi, A., Withall, J., Greaves, C., Thompson, J., Taylor, G., Medina-Lara, A., Green, C., Snowsill, T.; Johansen-Berg, H., Bilzon, J., Gray, S., Ladlow, P., Cross, R., Western, M., De Koning, J., Bollen, J., Moorlock, S., Guralnik, J. M., Rejeski, W. J. & Fox, K.  (In press). A randomised controlled trial and economic evaluation of a community-based physical activity intervention to prevent mobility-related disability in older adults: The REACT [REtirement in ACTion] study. Public Health Res.
  2. Demnitz,N., Stathi,  A.Withall, J., Stainer, C., Seager, P., de Koning, J., (…) Sexton, C.E. (in press). Hippocampal maintenance after a 12-month physical activity intervention in older adults: the REACT MRI study. NeuroImage.
  3. Stathi, A., Withall, J., Agyapong-Badu, S., Barrett, E.E., Kritz, Marlene, Wills, D., Thogersen-Ntoumani, C., Fox, K.R. (2021). Mobilising people as assets for active ageing promotion: A multi-stakeholder perspective on peer volunteering initiatives. BMC Public Health, 21, 150; doi.org/10.1186/s12889-020-10136-2
  1. Stathi, A., Withall, J., Thompson, J.L., Davis, M.G, Gray, S., de Koning, J., Parkhurst, G., Lloyd, L., Greaves, C., Laventure, R., and Fox, K.R. (2020) Feasibility trial evaluation of a peer volunteering active ageing intervention: ACE (Active, Connected, Engaged). The Gerontologist, 60, 3, 571–582. doi/10.1093/geront/gnz003/5342922. 
  1. Withall, J., C.J. Greaves, J.L. Thompson, J. de Koning, J.C. Bollen, S.J. Moorlock, K. R. Fox,(…) Stathi, A., for the REACT Study Research Group. (2020). The tribulations of trials: Lessons learnt recruiting 777 older adults into REtirement in ACTion (REACT), a trial of a community, group-based active ageing intervention targeting mobility disability. Journals of Gerontology: Medical and Biological Sciences. https://doi.org/10.1093/gerona/glaa051 
  1. Stathi, A., Withall, J., Greaves, C.J. et al. A community-based physical activity intervention to prevent mobility-related disability for retired older people (REtirement in ACTion (REACT)): study protocol for a randomised controlled trial. Trials 19, 228 (2018). https://doi.org/10.1186/s13063-018-2603-x 
  1. Withall, J., Thompson, J.L., Fox, K.R., Davis, M., Gray, S. et al, Participant and Public Involvement in Refining a Peer-Volunteering Active Aging Intervention: Project ACE (Active, Connected, Engaged), The Gerontologist, 58(2), 362–375, 2018, , https://doi.org/10.1093/geront/gnw148 
  1. Stathi, A, Withall, J, Thompson, JL, Davis, MG, Gray, S, De Koning, J, Parkhurst, G, Lloyd, L, Greaves, C, Laventure, R & Fox, KR 2019, 'Feasibility Trial Evaluation of a Peer Volunteering Active Aging Intervention: ACE (Active, Connected, Engaged)', The Gerontologisthttps://doi.org/10.1093/geront/gnz003 
  1. Withall, J., Jago, R. & Fox, K.R. The effect a of community-based social marketing campaign on recruitment and retention of low-income groups into physical activity programmes - a controlled before-and-after study. BMC Public Health 12, 836 (2012). https://doi.org/10.1186/1471-2458-12-836 
  1. Withall, J., Jago, R. & Fox, K.R. Why some do but most don't. Barriers and enablers to engaging low-income groups in physical activity programmes: a mixed methods study. BMC Public Health 11, 507 (2011). https://doi.org/10.1186/1471-2458-11-507 
  1. Withall, J., Jago, R., Fox K.R. Who attends physical activity programmes in deprived neighbourhoods? Health Education Journal 70(2) 206–216, 2010, DOI: 10.1177/0017896910379368 
  1. Withall, J, Jago, R, Cross, J. Families’ and health professionals’ perceptions of influences on diet, activity and obesity in a low-income community, Health & Place, 15 (4) 1078-1085, 2009, https://doi.org/10.1016/j.healthplace.2009.05.006

Book chapters

Stathi, A., Western, M., de Koning, J., Perkin, O. & Withall, J. (2018) Implementing physical activity programmes for community-dwelling older people with early signs of physical frailty. The Palgrave Handbook of Ageing and Physical Activity Promotion. Nyman, S. R., Barker, A., Haines, T., Horton, K., Musselwhite, C., Peeters, G., Victor, C. R. & Wolff, J. K. (eds.). United Kingdom: Palgrave Macmillan, p. 401-422

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