The communitarian PESO program is based on appropriate clinical guidelines and on validated behavior change principles. Implemented by an intervention team with expertise gained from current scientific research in weight control determinants, this program as well PICO, is free of charge for all interested adults who wish to manage their weight and health. It operates since 2005 with the aims to prevent obesity or reduce excess weight, as well as, some of the risks associated with obesity in adults through a change to steady healthy habits, attitudes and behaviors. PESO has 3 months duration and it is structured in 12 sessions of one and a half hour, once a week.

Aquatic Exercise program is organized in 24 sessions distributed over 12 consecutive weeks, with a frequency of twice a week. The duration of each session will be 60 minutes, being that 10 minutes are for patient reception, blood pressure control, pain register or others and the effective time inside the water is 45 minutes. The indoor pool works with an air temperature around 27±1ºC and water temperature is controlled for 30.5±5ºC. Workout is organized in order to have a progressive overload every week or every two sessions, when occurs an introduction of a new stimulus. Water is the main instrument to create resistance and only in the last weeks, according with participants progression and if the self-reported pain controlled, drag equipment will be added.

Pain, stiffness and other symptoms should be assessed by the Brief Pain Inventory (BPI); Numerical Rating Scale (NRS) and by the Knee Injury and arthritis Outcome Score (KOOS)

The MOS Short-Form Health Survey (SF-12)and the Beck Depression Inventory (BDI-II) will be used to asses Quality of life and Psychological status

Physical function will be assessed by the following functional tests: The Six Minutes Walking Test to verify aerobic capacity and the walking ability; The Chair Sit and Reach test for hamstring flexibility; The Back Scratch Test for overall shoulder range of motion; The Five-Repetition Sit-To-Stand Test for functional strength .

A dynamometer will be used for isokinetic assessment of knee strength (flexor and extensor muscles) and isometric knee strength, bilaterally; The Handgrip Strength Test will evaluate maximal isometric force of the muscles of the hand and forearm.

Kinematics and kinetics outcomes will be analyzed from gait test (gait speed, gait cycle, ground reaction forces and knee forces moments).

Body composition. Body Mass Index and a dual energy x-ray absorptiometry (DXA) scanner will be used to measure whole body lean mass, fat mass and bone mineral content.