When I make the effort, and it can be an effort, to get myself to the gym and exercise for just 30 minutes, it makes a tremendous difference in my attitude and my ability to get things done.
I have found that exercising in the morning works best for me, but find a time that works best for you. Afternoons have always been my most productive time, so doing some cardio exercises in the morning helps give me more focus in the afternoon.
According to WebMD, when you exercise, your brain releases chemicals called neurotransmitters, including dopamine, which helps with attention and clear thinking. People with ADHD often have less dopamine then usual in their brain.
Fitness can have the following benefits for adults with ADHD:
Executive Function (EF) refers to brain functions that activate, organize, integrate and manage other functions. It enables individuals to account for short and long term consequences of their actions and to plan for those results. It also allows individuals to make real time evaluations of their actions, and make necessary adjustments if those actions are not achieving the desired result.
There are differing models of executive function put forth by different researchers, but the above statements cover the basics that are common to most. Two of the major ADHD researchers involved in studying EF are Russell Barkley, PhD, and Tom Brown, PhD.
See how Barkley and Brown break down EF [National Resource Center on ADHD]