Benefits of physical activity (PA) as supportive care in cancer have been widely demonstrated by the scientific community. However, survivors who have completed chemo-radio-immunotherapy treatments doesn't achieve PA recommendations on average. This reinforces the need to identify factors influencing PA level, and to propose a multilevel model (macro-, meso-, micro-level) to understand better what facilitates the adoption and maintenance of active behaviour and what hinders it. To date, there is no ecological model in France explaining this behaviour in the post-treatment phase of breast, colorectal, prostate, and lung cancers. From this initial model, we seek to design an educational and motivational intervention in PA.

Thus, the investigators propose to test the feasibility of implementing an individualized program to increase and maintain level of physical activity and to decrease sedentary behaviours in physically inactive cancer survivors. This program is based through and identification of barriers and facilitators of an active lifestyle among this population.

In 2008, 3 million French people had experienced cancer in the last 15 years, compared to 18 million in 2022. Post-treatment marks a break with the intensive care pathway. It frequently leads to changes in the lifestyle of these patients. During this period, behaviors conducive to maintaining their state of health remain important.

Among these behaviors, Physical Activity (PA) is an integral part and brings many post-treatment benefits. Despite the evidence of PA benefits in adult cancer survivors who have completed chemo-radio-immunotherapy treatments, the majority of those with good prognosis cancer are insufficiently active. Patient survival tends to increase by 20% thanks to scientific progress and the improvement of cancer management. At the same time, patients experience adverse effects for an extended period after cancer treatment. It would take an average of 10 to 15 years to note a decrease in the psychological, physical, professional, and socio-economic repercussions of cancer. These repercussions do not totally disappear over time. We have a particular interest in this post-treatment period, where the end of treatments marks a break within the "clinical pathway". The patient then joins the "care pathway" where he/she needs to have an autonomous management of his/her health behaviour.

The study of factors - clinical, psychological, cognitive, behavioural, social, or even linked to the clinical pathway and the geographical environment - involved in regular PA practice with breast, prostate, colorectal, or lung cancer survivors, would allow us an overview of what shapes a complex behaviour like PA.

In view of these needs to better understand and act on the complex behaviour of active lifestyle, the main objective of our research is to design, implement, and evaluate an individualised educational and motivational program, constructed from an explanatory ecological model. The educational and motivational program thus conceived will help in supporting good prognosis and physically inactive cancer survivors (breast, colorectal, prostate, or lung cancers) in initiation and maintenance of their PA.

Deployment of this interventional approach will provide more support to cancer survivors at the end of their treatment at a national level while considering the specificities of healthcare fields. To consider these variety, transferability criteria will be taken into account.

Thus, the investigators propose to test the feasibility of implementing an individualized program to increase and maintain level of physical activity and to decrease sedentary behaviours in physically inactive cancer survivors. This program is based through and identification of barriers and facilitators of an active lifestyle among this population.

Inclusion Criteria:

• 18 years ≤ age < 75 years
• survivors of primary non-metastatic breast, lung, prostate or colorectal cancer (stage I, II or III and primary, second and relapse included)
• 3 weeks to 20 years post-treatment (surgery, chemotherapy, radiation therapy and/or immunotherapy) not including hormonal therapy
• Whose ability to participate in the APA intervention has been certified by a medical certificate issued by physician
• Availability and willingness to invest in the DEFACTO study during the program (3 months) and during the post-program follow-up (12 months)
• Participating, on average, in no more than 150 minutes of moderate physical activity or no more than 75 minutes of vigorous activity per week
• Average at least 6 hours a day of sedentary behaviours
• Able to read, understand and complete questionnaires in French
• Able to use connected device (Vivosmart4®) and to perform simple operating actions (press a button, recharge the battery)
• possessing a smartphone which can download Garmin Connect application ®
• Able to walk unassisted
• French speaking and living in France
• having signed the consent form

Exclusion Criteria:

• Current evidence of metastatic disease
• Having an absolute contraindication by a physician to practice PA
• Using treatments that influence blood pressure, cardiotoxic drugs, painkillers (morphinics);
• Using cane or walking aid
• Deprived of liberty by judicial or administrative decision
• Person under guardianship or curatorship
• Pregnancy and/or lactating women
• Being diagnosed of any cardiac abnormalities