How can you make your marathon workouts more efficient and obtain the greatest benefit in the least amount of time? If you only have time for a few runs per week, 5 or 6 miles at an intensity easy enough to let you sing along with your iPod isn't going to cut it. The fewer workouts you do, the greater the importance of each workout. Below are the most effective workouts for improving your marathon performance.
What: The staple of marathon training, long runs are significantly longer than any of your other daily runs. Since your body has a much better concept of time than of distance, the amount of time spent on your feet is more important than the number of miles you cover.
Why: It has been known since the 1960s that the ability to perform prolonged endurance exercise is strongly influenced by the amount of carbohydrates stored in skeletal muscles (glycogen), with fatigue coinciding with glycogen depletion. To the marathoner's benefit, the human body responds rather elegantly to situations that threaten or deplete its supply of fuel. When glycogen is depleted by running, muscles respond by synthesizing and storing more than what was previously present. Empty a full glass, and you get a refilled larger glass in its place. The more glycogen you have packed into your muscles, the greater your ability to hold your marathon pace to the finish.
In addition to serving as a stimulus to store more glycogen, long runs improve your blood vessels' oxygen-carrying capability by increasing the number of red blood cells and hemoglobin concentration. They also create a greater capillary network, providing more oxygen to your muscles, and increase mitochondrial density and the number of aerobic enzymes, increasing your aerobic metabolic capacity.
Long runs also prepare your muscles and connective tissue to handle the stress of pounding the pavement for 26.2 miles. For this reason, all of your long runs should be on the road, unless you're planning on running a trail marathon.
How: Your long run should total no more than 30 percent of your weekly mileage, but this rule can be broken in the name of necessity if you plan on running only a few times per week. Run at a comfortable, conversational pace, which is about two minutes per mile slower than 5K race pace, or about 70 to 75 percent of maximal heart rate. Lengthen your long run by 1 mile each week for 3 or 4 weeks before backing off for a recovery week.