To get the most from your brain as you train . . . Exercise within the boundaries of your fitness level. Work out a training programme that suits you, and never overdo it. From week to week, gradually increase the length of your exercise sessions and, along with improving your physical fitness, you will soon also begin to feel the mental benefits.
Stay aerobic. Unless you are a serious athlete training for a specific race, there is little need to move outside your aerobic threshold when you exercise. Exercise at a comfortable pace and keep your breathing regular. While running or cycling you should be able to hold a conversation without feeling out of breath or panting. If you do feel out of breath, it is time to slow down.
Warm down. If you do need to do high- intensity exercise, make sure you warm up and warm down with some easy aerobic exercise before and after to get your brain back in gear. When doing high-intensity training you should never finish feeling completely exhausted. If you do, it means you are training too hard and you will not benefit from this.
Stay hydrated. Dehydration will stop your brain and body from functioning normally. If you do not drink plenty of water during and after exercising you will not feel any of the rewards, either physically or mentally. If anything, it will slow you down. Don't risk it; always have water close at hand.
Keep goals. It is difficult to imagine running a marathon if you have never walked a mile. Stay focused and set manageable goals that will take you just outside your comfort zone. When you reach one goal then make another. The mental strength needed to run a marathon will then develop naturally along with your physical fitness.