Objectives To investigate the impact of tele-supervised prehabilitation on functional capacity in frail colon cancer patients undergoing colorectal resection and to evaluate the effects of prehabilitation on muscle strength and endurance, quality of life (QoL), executive functions, fatigue and inflammatory and metabolic parameters.

Methods A randomized controlled trial will be conducted. Patients will be randomised into either a prehabilitation group (PREHAB) or a control group. Prehabilitation group will participate in a 4-week telerehabilitation before surgery while the control group will receive usual care and World Health Organization recommendations on physical activity for health before surgery. Program exercise will consist of three moderate-intensity aerobic and resistance sessions per week. Subjects will have assessments at baseline, pre-intervention and 8 weeks after surgery. The primary outcome will be functional capacity measured by using the 6-min walk test. The secondary outcomes will be: physical measurements, QoL, level of physical activity, executive functions, fatigue, body composition, blood test, energy expenditure.

Objectives Primary objective: To assess if a 4-week tele-supervised prehabilitation is effective in improving post-operative cardio-respiratory fitness in frail colon cancer patients.

Secondary objectives : To examine if a 4-week preoperative tele-supervised prehabilitation has beneficial effects on muscle strength and endurance, on quality of life, on executive functions, on fatigue, on inflammatory parameters and on metabolic disruption pre-surgery.

Background In Belgium, colon cancer is the third most common cancer in men and the second most common in women and is the second cause of cancer death. Surgery is currently the primary treatment for stage I to III. Studies have shown that patients with poor preoperative physical fitness are less able to cope with the adverse effects of surgery and hospitalization resulting in increased risk of mortality, postoperative complications and functional recovery time. Moreover, approximately 60% of colon cancer patients are older than 70 years at diagnosis and more than 50% of older cancer patients have frailty or pre-frailty. Frailty is a state of vulnerability decreased functional reserve, impairment or dysregulation in several physiological systems, and reduced capacity to recover physiological homeostasis after a stress. Nowadays, no frail definition is clearly defined. One widely accepted definition uses the Fried criteria including the assessment of weight loss, physical exhaustion, physical activity level, grip strength and walking speed. Preoperative frail colon cancer patients have a significantly higher risk of adverse postoperative outcomes including institutionalization, length of stay, morbidity and mortality. It seems relevant to intervene during the preoperative period to improve the patient's functional capacity before the surgery, via physical training to overcome the stress of the surgery and to improve postoperative recovery. This process is called "prehabilitation". Structured and supervised programs have shown to be effective and feasible. However, time, resources and expensive care are often a barrier for the patient. Thereby, a home-based tele-supervising rehabilitation would be an attractive therapeutic option to offer a distinct advantage in this regard. To date, no study has studied the effects of tele-supervised prehabilitation in these "frail" patients.

Study design A single-blind, randomized, controlled trial will be conducted. Participants will be randomized into either a prehabilitation group or a control group. An assessor who will be blinded to group allocation will collect outcomes measures for each participant.

Study sample To be eligible for this study participants will need to meet the following criteria: diagnosis of colon cancer requiring surgery; more than 65 years of age; able to read, write and understand French; Frailty phenotype criteria ≥ 3. Frailty was assessed using the components of the Frailty Phenotype, which was first developed by Fried et al., which consists of five criteria: weight loss, exhaustion, low physical activity, slowness, and weakness.

Participants will be excluded if they have a physical impairment that would seriously impair physical mobility; the surgery is an emergency; have a neuropsychiatric disease.

Intervention Participants allocated to the prehabilitation group will undertake a telerehabilitation program that will start 4 weeks before the surgery while participants in the control group will receive usual care and World Health Organization recommendations on physical activity for health before surgery.

The telerehabilitation program will combine aerobic and resistance training three sessions per week. Each 60-min session will begin and end with a five-minute warm-up/cool. The warm-up will be followed by 25 minutes of aerobic training. Aerobic exercise can include brisk walking, jogging, cycling, or swimming according to patient's preference. The intensity of the exercise was set between 60 à 75% of maximum heart rate (maximal heart rate=220 - age). And between 12 and 16 on Borg's Rating of Perceived Exertion Scale. Each participant will wear a heart monitor. The aerobic training will be followed by resistance exercise performed on eight exercises targeting major muscle groups (abdominal, hamstring, quadriceps, triceps, gluteus maximus, paraspinal muscles and shoulder muscles). Intensity must be between 12 and 16 on the Borg's Rating of Perceived Exertion Scale. A physiotherapist will provide detailed information about the program. The patient will receive a brochure in which there will be descriptions and pictures of exercises and a video including the resistance program was recorded on a website. The researcher will conduct weekly telephone calls with the participants. The aim of these calls will be to solve any problems of carrying out the training sessions and to discuss about possible adverse events. Moreover, the researcher will give messages of support and encouragement to improve adherence to the program.

Outcome measures Outcome measures will be assessed at three time points: at baseline (T0), one day before the scheduled date of surgery (T1) and 8 weeks after the surgery (T2).

Primary outcome will be cardiorespiratory fitness 6min walk test). Secondary outcomes will be muscle strength and endurance (isokinetic dynamometer and 1-min sit-to-stand-test), quality of life (EQ-5D-3L questionnaire); level of physical activity (International Physical Activity Questionnaire Short Form); fatigue (Functional Assessment of Cancer Therapy: Fatigue); executive functions (Trail Making test and fluency verbal test) ; blood test (neutrophil lymphocyte ratio, C reactive protein, fasting glucose, fasting insulin and cholesterol will be measured by bioelectrical impedance analysis); energy expenditure (Sensewear® armband).

Inclusion Criteria:

• Diagnosis of colon cancer requiring surgery
• More than 65 years of age;
• Able to read, write and understand French;
• Frailty phenotype criteria ≥ 3

Exclusion Criteria:

• The participants have a physical impairment that would seriously impair physical mobility;
• the surgery is an emergency;
• The participants have a neuropsychiatric disease.