Just as it took time for you to build up to running a mile without stopping, it will take time for you to improve your muscular and cardiovascular endurance so you can run a mile without being completely depleted. Following a regular fitness program aimed at building your leg muscles and improving your aerobic capacity will help you run a mile without getting really tired. Furthermore, running in properly fitted shoes improves the mechanics of your body during a run, optimizing movement and fuel efficiency so you are not so tired.
Incorporate a resistance training program into your weekly fitness schedule to improve the muscular endurance of your upper body and core muscles. These muscles are engaged during a run to keep your trunk upright, your chest cavity open and your arms in an optimal running position. Do two exercises per muscle group for three sets of 15 to 20 repetitions.
Perform a lower body resistance training workout toward the end of the week, after your running routines. Include squats, walking lunges and one-leg dead lifts, increasing the strength and endurance of your leg muscles so they can propel your body weight with ease during a run, reducing your tiredness. Do three sets of eight to 12 repetitions per exercise.
Use the elliptical machine one day per week for the length of time it takes you to complete 1 mile. Pedaling against constant resistance builds the strength and endurance of your quadriceps muscles so they do not tire during your run. Set the resistance of the machine within the latter third of resistance levels; for instance, if the resistance level goes up to a level 20, most of your time should be spent between levels 13 and 20.
Sprint up a hill for 30 seconds then walk down the hill, totaling 25 minutes. Sprints increase the point at which your muscles become too tired to contract, ultimately enhancing your cardiovascular capacity so you do not tire during your run. Do hill sprints one day per week.
Eat slow-digesting carbohydrates like natural peanut butter and an all-fruit spread on whole wheat bread about two hours before your run. Slow-digesting carbs ensure you have sustained energy for your workout so you do not get really tired.
Eat fast-digesting carbohydrates like graham cracker cookies immediately after every resistance and running workout. Fast-digesting carbs optimally replenish the glucose in your muscles so you have the energy for your next run, reducing your level of tiredness.
Do an easy jog-and-walk warmup for 10 minutes followed by a few quick stretches prior to your mile run. Keep track of your running and lifting workouts to ensure you are gradually improving your endurance and strength.
Gradually build up to running a mile without stopping to reduce your risk of extreme muscle soreness.