Training

Across all activities, there cannot be more than 25 workouts on the watch.

support.garmin.com/.../

Etupes25 said:

Across all activities, there cannot be more than 25 workouts on the watch.

Just a note: the limit is for non-scheduled workouts. You can schedule "unlimited" number of workouts and send them to the device. It is written clearer in this article: How to Send Workouts to a Garmin Device | Garmin Customer Support 

While non-scheduled workouts are in the folder //GARMIN/Workouts on the watch, scheduled ones are in //GARMIN/Workouts/Scheduled, so they are indeed stored separately

manually deleted?

Thank you, problem solved.

I had selected a marathon training and it was imposing a schedule of several consecutive workouts, which probably exceeded the number of 25.

I am quite surprised that there is an option to have only 25 workouts. It's really beyond the capacity of the facility. I find the Tactix 7 to be a pretty fancy, premium machine

xsanchox said:

I had selected a marathon training and it was imposing a schedule of several consecutive workouts

Workouts that are on the calendar don't count towards the 25 limit. If you send a workout to the watch instead of putting it on the calendar, it does count.

The watch comes from the factory with pre-loaded workouts for many activities. All these count towards the limit.

If you want, let's say, to have 25 of your favorite running workouts always available on the watch, you would have to go into each activity, look up the workouts saved on the watch, delete them (or use the USB connection to empty the folder) before you can sent your top 25 to the watch.