Yes, you can – however, don’t push it. If you are following the “best” option and participating in a fast of any kind, you should take care not to overwork your body. Similarly, if you are experiencing a superficial colon cleansing reaction, you should also take a break. The key to exercising during your colon cleanse is “self-assessment”. If you feel good and strong, then exercise – but keep an easy routine. Walk, don’t run – and don’t do any heavy-lifting exercises.