1. Primary Endpoint - disease free survival (DFS) (Time Frame - 8 years (after Last Patient Out (LPO))): DFS is defined as the time from randomization to locoregional or metastatic recurrence or the appearance of secondary cancer or death, whichever occurs first. Recurrence may be either histologically proven or evidenced by imaging via MRI or CT. Isolated CEA evaluation will not be sufficient to determine a relapse.
Secondary outcome:
1. Secondary Efficacy Endpoint I - relapse free survival (RFS) (Time Frame - 8 years (after Last Patient Out (LPO))): RFS is defined as the time from randomization to locoregional or metastatic recurrence of colorectal cancer or death, whichever occurs first
2. Secondary Efficacy Endpoint II - overall survival (OS) (Time Frame - 8 years (after Last Patient Out (LPO))): OS is defined as time from randomization to death from any cause
3. Physical Activity Endpoint I - physical activity measured by MET-hours (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of physical activities measured by MET-hours in the domains "work", "leisure time ", "sedentary behavior" and "transporation" by Global Physical Activity Questionnaire (GPAQ) within each study arm and compared between study arms at baseline, at 3, at 6, at 12, at 24 and at 36 months
4. Physical Activity Endpoint II - endurance exercise measured by MET-hours (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of endurance exercise measured by MET-hours by pulse-control in arm A at 3, at 6 and at 12 months
5. Physical Activity Endpoint III - performance enhancement measured by MET-hours by ergometry (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of performance enhancement measured by MET-hours by ergometry within each study arm (arm A at baseline, at 3, at 6 and at 12 months; arm B at baseline and at 12 months) and compared between study arms at baseline and at 12 months
6. Physical Activity Endpoint IV - physical activity measures (Time Frame - 8 years (after Last Patient Out (LPO))): Correlation of MET-hours in the domains "work", "leisure time ", "sedentary behavior" and "transporation" by Global Physical Activity Questionnaire (GPAQ) and results of endurance exercise as well as performance enhancement by ergometry (both measured by MET-hours) with DFS, RFS and OS
7. Patient Reported Outcome Endpoint I - fatigue (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of fatigue as measured by EORTC - QLQ FATIGUE CAT Theta scores compared between study arms. Score has no fixed upper and lower limit and a high score represents a high level of fatigue.
8. Patient Reported Outcome Endpoint II - emotional functioning score (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the emotional functioning score (based in the functional scale EF) as measured by EORTC QLQ-C30 emotional functioning (based on items) compared between study arms, where a high score for a functional scale represents a high/healthy level of functioning.
9. Patient Reported Outcome Endpoint III - physical functioning score (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the standardized physical functioning score (based on the revised functional scale PF2) as measured by EORTC QLQ-C30 physical functioning compared between study arms, where a high score for a functional scale represents a high/healthy level of functioning
10. Patient Reported Outcome Endpoint IV - global quality of life (QoL) score (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the standardized global health status/QoL score (based on the revised global health status/QoL QL2) as measured by EORTC QLQ-C30 summary score compared between study arms, where a high score for the global health status/QoL represents a high QoL.
11. Patient Reported Outcome Endpoint V - patient reported outcomes (fatigue, emotional functioning, physical functioning, global quality of life) (Time Frame - 8 years (after Last Patient Out (LPO))): Correlation of all patient reported outcomes explained above (fatigue, emotional functioning, physical functioning, global quality of life) with MET-hours
12. Body Composition Endpoint I - body mass index (BMI) (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the influence of BMI on DFS, RFS and OS
13. Body Composition Endpoint II - body fat (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the influence of body fat on DFS, RFS and OS
14. Body Composition Endpoint III - waist circumference (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the influence of waist circumference on DFS, RFS and OS
15. Cardiovascular Endpoint - cardiovascular complications (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the incidence of cardiovascular complications (myocardial infarction, stroke, newly diagnosed diabetes mellitus, newly diagnosed hypertension)
16. Safety Endpoint I - serious adverse events (SAEs) (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of the incidence of physical activity related SAEs and physical activity related deaths in both arms
17. Safety Endpoint II - time to SAEs (Time Frame - 8 years (after Last Patient Out (LPO))): Evaluation of time from study start to physical activity related SAEs
18. Exploratory Endpoint - molecular and biochemical markers (will be defined during the course of the study) (Time Frame - 8 years (after Last Patient Out (LPO))): Correlation of molecular and biochemical markers with DFS, RFS, OS and with physical activity. The analysis of molecular markers will depend on the markers which will be defined during the course of the study in addition to Insulin & ILGF.
Experimental: A - endurance exercise All patients receive a pulse-controlled endurance exercise program based on the study results by O'Donovan. The individual pulse-controlled endurance exercise should be performed 3 times a week. On the basis of age, weight, sex and body fat the normal weight will be calculated. The kilocalories (kcal), which correspond to the metabolic equivalent task (MET) hour per week, will be calculated after age and gender adjustment of the normal weight. The endurance exercise will be increased gradually until reaching 18 MET-hours/wk during the year of endurance exercise. Patients in arm A can perform different types of endurance exercise (bicycling, cross walking, jogging, walking, nordic walking, cross country skiing)
Other: B - control arm Patients in this arm should maintain their habitual physical activity pattern as before the diagnoses of colorectal cancer.
