Our main challenge is to develop a novel physical activity intervention to promote exercise participation sustainability and effective health benefits in type 2 diabetes (T2D) population with minimum health risks. The relevance of this study is supported by four cornerstones: 1) The Portuguese love football and there seems to be a major potential in the implementation of football practice as part of the prevention and treatment of noncommunicable diseases for the middle-aged and elderly Portuguese population; 2) no studies have assessed the feasibility and safety of a walking football exercise program for middle-age and older patients with T2D; 3) the proposed investigation relies on robust methodology; 4) this intervention can have further sustainability with the enrollment of football clubs and primary health care units.

This work will be a quasi-experimental study where we aim to test the feasibility and safety of walking football in patients with T2D. The recruitment of participants will be held in primary health care units by Family Medicine medical doctors. All participants will receive instructions to maintain daily-life routines (lifestyle-related physical activity and dietary pattern), and to continue with usual care (diabetes consultations on primary health care units and pharmacological regimen) along the studies duration. All participants will receive basic sports material (sports bag, T-shirt, and sports shoes). Participants will be organized in two teams of 20 players. Each team will have 60-min walking football exercise sessions three times per week (non-consecutive days), during three months (36 sessions). Different walking football exercise strategies will be developed according to participants' motor skills and tested with dose-escalated intensity for its safety (acute effects on capillary glycaemia, blood pressure, foot impact, exercise-related injuries and adverse events) and enjoyment. Exercise intensity will range between light to vigorous. No submaximal or maximal exercises will be tested. Cumulative short-term effects will also be analyzed along the three months through pre- and post-study evaluations. Exercise sessions will be conducted on a sports hall (indoor court) by a football coach and supervised by an exercise physiologist and a nurse.

Inclusion Criteria:

• diagnosis of type 2 diabetes for at least 12 months;
• glycated hemoglobin bellow 10 %;
• not having started insulin therapy in the previous six months;
• not having started therapy with sulfonylureas in the previous six months;
• major complications of diabetes screened and controlled (diabetic retinopathy, diabetic nephropathy and diabetic foot);
• no symptoms of coronary artery disease;
• no cardiovascular, respiratory and musculoskeletal contraindications to exercise;
• not under cancer treatment (radiotherapy or intravenous chemotherapy);
• without limitations in gait or balance;
• independent living in the community;
• not engaged in supervised exercise;
• non-smokers at least for 6 months.

Exclusion Criteria:

• cardiological stress test with cardiac or hemodynamic problems