The profile page is a great place to see a summary of a user's activities.
The calendar widget gives you an overview of a user's activities by activity type and by date. You can see week by week how many activities this user has recorded, which days the user was active and the total activity time for that week.
The recent achievements area, just below the calendar widget, shows you what achievements this user has recently gotten. It will show recent Personal Records, KOMs, etc…
Activity bar chart:
This chart allows you to filter the visible activities of a user's. The activities displayed on the profile page are filtered according to your selection in the chart. You can choose to view the activities grouped either by week or month and then you can select a week (or month) to display by clicking on the vertical bar in the chart.
On the right side of the profile page you see the essential stats for a user and you can quickly see how you compare to the user whose profile you're viewing.