Cancer Exercise
 Calculator & Logger

This website is for colorectal cancer survivors looking to use exercise to lower their risk of recurrence and improve their odds of survival by replicating the findings of the large CHALLENGE trial (https://www.nejm.org/doi/full/10.1056/NEJMoa2502760).

The CHALLENGE Trial

The CHALLENGE trial is a landmark international study that investigated whether a structured exercise program could improve outcomes for colon cancer survivors.

The CHALLENGE trial provides the strongest evidence yet that exercise is not just safe but also effective in reducing the risk of colon cancer returning and in increasing survival after treatment. The program’s focus on MET hours helps survivors track and achieve activity levels shown to improve outcomes.

What Was the CHALLENGE Trial?

• The trial enrolled 889 participants from six countries, mostly in Canada and Australia, with a median age of 61. About 90% had stage III colon cancer, and all had finished standard treatment.

Key Results

• After five years, those in the structured exercise group had an 80% disease-free survival rate, compared to 74% in the education group.
• The exercise group had a 28% lower risk of cancer recurrence or new cancers and a 37% lower risk of death at eight years.

How Did the Exercise Program Work?

• The core goal was to increase recreational physical activity by at least 10 MET-hours per week above each participant’s starting level.
• The program was tailored to each person’s fitness, preferences, and barriers. Activities included walking, cycling, swimming, or other moderate-to-vigorous exercises (4–10 METs).

How to Use This Information

Tracking your MET hours, as done in the CHALLENGE trial, can help you set and reach activity goals proven to lower your risk of recurrence and improve survival. Even moderate increases in physical activity, like brisk walking, can make a significant difference.

What Are MET Hours?

MET hours are a way to measure how much energy you use during physical activity. “MET” stands for Metabolic Equivalent of Task. One MET is the amount of energy your body uses at rest, like sitting quietly. Activities are assigned MET values based on how much more energy they require compared to resting. For example, brisk walking is about 4 METs, meaning it uses four times the energy of sitting still.

To calculate MET-hours, multiply the MET value of an activity by the number of hours you do it. For instance, walking briskly (4 METs) for 1.5 hours equals 6 MET hours (4 x 1.5 = 6). Tracking MET hours helps you understand your overall activity level and set goals proven to benefit your health as a colon cancer survivor.