Adjust workout time before starting a workout

Another app's feature that allowed me to adjust my workout time just before starting my workout was very useful. The option was right at the top, just one click and I could alter that days' training time to accommodate my available time. This feature was particularly useful on days when I was not feeling up to a full workout or when I was under a time constraint. With Dr. Muscle, this feature may exist but I haven't come across it yet. I do see I can make the training period change within the settings/program but I don't know if that is a 'global setting' or a 'next workout setting.' For this feature, I only want to change the next workout. Again, Dr. Muscle may have this feature front and center but I'm not seeing it; it's not intuitive.