Suunto 3, Suunto 5, Suunto 5 Peak, Suunto 9, Suunto 9 Baro, Suunto 9 Peak and Suunto 9 Peak Pro have the following fitness features provided by Firstbeat analytics.
You can read more about it here:
Fitness level   (VO2 max.) - from running and walking sports
Sleep quality assessment
Stress level
Body resources
Fitness age
You can also check the user guide of your Suunto watch under the Features section for Fitness level, Sleep tracking and Stress and recovery.
Happy training!