Assessing Cognitive Performance Among Adults With Attention Disorders Working on Treadmill

Randomized clinical trial in which individuals who have been diagnosed with ADHD and are regularly treated with Methylphenidate will be test for cognitive performance and will be randomly examined in the following four conditions: * While taking Methylphenidate and sitting at a desk * While taking Methylphenidate and walking on a treadmill workstation * Without taking Methylphenidate while sitting at a desk * Without taking Methylphenidate while walking on a treadmill workstation The investigators will compare the cognitive achievements outcomes and evaluate the efficiency of studying in each of these four conditions.