Exercise is helpful to all brain conditions, including ADD/ADHD. Any exercise is helpful but specific exercise may be more helpful in conditions accompanying ADD such as anxiety, insomnia, depression, and PTSD.
The brain is a highly energetic organ. Even though it weighs about three (3) pounds, it uses 20% of all food energy per day. It is very sensitive to insulin resistance, that can lead to diabetes. When insulin resistance occurs, it prevents nutrients from entering brain cells, including carbohydrate (sugar) and amino acids (protein). This can lead to poor brain cell function: decreased memory, lack of focus, easy distraction, and brain fog.
Exercise decreases insulin resistance, making cells more able to respond to insulin, and, therefore, more easily uptake carbohydrate (sugar) and amino acids (protein). The more frequent and more intense the exercise, the more sensitive cells become to insulin. Ideally, exercise should be performed daily and all muscles should be involved in the exercise. If only a few muscles are selected, like in only running or walking, those muscles adapt to the exercise and can become again “complacent” to the action of insulin.
In a perfect world, every muscle should be exercised and every muscle rested equally. I personally do a strength circuit program where I use exercise machines, do 24 different stations, and I do two circuits per workout, or 48 different exercises in about an hour. This means I cannot rest between exercises if I want to get them done in a timely manner before work in the morning. I push the muscles at each exercise station to exhaustion where they lose strength and “burn”. Since I move to the adjacent machine, I am huffing and puffing, exercising my heart and cardiovascular system as well.
ALL exercise is good exercise. The most important issue is: can you do the exercises daily without fail, rain or shine, hot or cold? This means for most, an exercise regimen performed indoors is best. If you have a goal, like weight loss, more is better. If you want to shape your body, then balance and symmetry should be achieved—sculpting the body with weight training. If you simply want to remain active and vital instead of immobile and stiff, then working out less may be adequate.
All exercise will improve brain function, but if you desire to sleep better, exhaustive exercise is better than lallygagging around the gym will get better results. The same with anxiety and depression—more is better; intense is better than mild. REM sleep is accompanied by secretion of proteins that help brain cells grow (called neuroplasticity) and memories form (chemically for permanence). The more one exercises, generally, the better the REM sleep. The better the sleep, the better the brain functions with focus, tasking, and organization—improving ADD/ADHD.