how do I add exercise minutes that I did separately to my fit bank
You need to edit the ‘Activity Log and Fit Credit’ or the featured workout. You can look up to the user’s manual to get guidance.
First, click on your Mii to make sure you're in the profile that you want to add the activity to. Then on the lower left, click on the "graph" icon. At the top are some buttons, click on the one that says, "Fit Credits." Once the Fit Credits bar graph is displayed, you'll note a button on the graph (to the right) that says, "Activity Log." Just follow the screen prompts from there to enter activities you've done outside of Wii Fit!
~^~ Esoterixia ~^~