From your 'My Hub' page (please see below)
On the left hand side of your account, you will see the side menu in which you can select 'workouts'.
You can then simply click 'Create Workout' at the bottom of your page
Enter your workout name and 'Create'
You can then simply hit the 'Add Exercise' button to search our database of over 7,500 exercises with videos
To search for a specific exercise just hit the search bar within the page and type the exercise.
Then simply select the tickbox next to all of the exercises you would like in your workout and finish by clicking 'Add Exercises'
You will then need to add all the important information in regards to parameters within each exercise which can be edited by simply selecting the different columns and entering the amounts, times etc.
Just remember to hit the 'Save Changes' button once finished!