This will depend entirely on your goals. If you’re wanting to optimize hypertrophy and strength, we don’t recommend adding anything; if you enjoy lifting with higher frequency, we recommend switching to the 4 or 5 day program options, located in the “Settings” page of “Month View”. If you’re wanting to cross-train, adding in low effort activities (Pilates, Yoga, cardiovascular-based training, etc.) can be integrated without hindering progress as long as it’s not done excessively. Recovery is just as important as lifting for strength and muscle gain. We don’t recommend adding in additional high effort training and/or very long duration physical activity.