I would like to add my own customization of activity log just as you can for the food log. It would be nice to just free text in an activity, how long or far and put in calories burned or steps taken. Many people can wear monitors that keep track of various things now. I find the pre-determined not suitable. If this is possible please enlighten me.

I agree that this would be great. It has been discussed in the past as a possible future option, but there is not capability for it at this time. Sorry.