What is specificity and why is it important?
At its core, training is all about the principle of adaptation. Your body adapts to the demands you place upon it by growing stronger and becoming more efficient. For example, when you run more miles, your heart increases the efficiency at which it pumps blood to working muscles, and mitochondria, the aerobic energy power plant of the cells, grow in number and size. Due to the principle of specific adaption, the closer you can perform exercise that mimics the exact demands you’re preparing to undertake, the better you’ll become at that specific exercise.
Obviously, the principle of specific adaption applies generally as well as at a micro level, meaning running more mileage is going to make you a better runner compared to a session of kettlebell exercises. However, while all types of running will generally help you improve as a runner, race-specific training will produce better results at a particular distance.
As the name implies, race-specific training means training for the specific physiological demands of your race distance. While this might sound simplistic, the difference between the physiological demands of commonly run race distances can be quite different. Certainly, there is some overlap between distances in close proximity, such as 5K and 10K, but there is a large difference between the specific demands of longer races such as the marathon and half marathon. Understanding these differences and applying the correct workouts is the founding principle behind race-specific training.