You build muscle during the Strength Building phase. During this phase you increase the number of muscle fibers in your leg muscles, as well as the mitochondria and enzymes needed to breakdown lactates during exercise. The Strength Building phase focuses on your ability to produce energy. It also raises your lactate threshold. Workouts during this phase are characterized by hills - hill running and hill drills. Getting stronger is your goal during this time. The Strength Building phase should last about 8 weeks.

If your ultra is on a very hilly course, you may want to increase the number of weeks in this phase to 12. If you're an experienced runner (if you've been running for over 3 years without injury, or have completed 3 marathons), start doing hills (strength building) in the second half of the Base phase. Do one hill workout per week after the first 2 weeks of the Base Building phase. You can do up to two hill workouts per week during the Base Building phase, but don't do a second hill workout if you're running a race that weekend.

In 1979 I had the opportunity to meet with Arthur Lydiard. During our conversation he emphasized the importance of hill training. Lydiard had all his athletes, from marathoners like Barry Magee, 5,000m runner Murray Halberg, to 800m runners like Peter Snell, run hills during both the Base Building and Strength Building phases of their training. Don't increase your weekly mileage during the Strength Building phase, and the length of your long run should remain constant through this phase. Increase the number of hill workouts you do each week, as well as the number of hill repeats you do each session. Don't do more than 3 hill workouts per week and no more than 12 hill repeats per workout.
You can race during the Strength Building phase. If you choose to race, reduce the number of hill workouts by one during race week. You shouldn't require time off, either before or after a race during the Strength Building phase.

Lactate Threshold Workouts

Hill training is an excellent form of a lactate threshold (LT) workout. The purpose of this workout is to build muscles, develop extra capillaries and improve the energy production system in your muscles. It's designed to raise your heart rate up to 95% for at least 2 minutes at a time, then allow your heart rate to drop down between the hard efforts. Start with four 2-minute hard efforts and increase that number each week. Running hills is the best way to raise your heart rate. Don't worry about speed during these hard efforts.

Hill Training

Hill training consists of hill running and hill drills. Hill Training isn't as hard on your body (specifically your legs) since running uphill is less jarring. Research has shown that periods of near maximum heart rate effort for 2-6 minutes produce optimal gains, and hill training produces significant gains in four key measures:

·           Improved running economy.

·            Increased VO2 max.

·           Improved vVO2 max (running speed at VO2max)

·           Increased lactate threshold (the ability of muscles to clear lactate from blood)

Hill Running:

Find a hill that's reasonably steep - around 6% grade is perfect. It should take you at least 2 minutes to run up the hill. Focus on your body position going up the hill and going down the hill. On the way up: shorten your stride slightly, increase your knee lift and arm action, and run up on your toes - getting a good push from your hips, knees and especially your ankles and toes. On the way down the hill: lengthen your stride slightly by increasing your follow-through (high foot in the back of your stride; drop your hands so they're near your hips / waist; lean down the hill; focus on landing on the midfoot or forefoot, not on your heel (which will cause a braking action and tremendously increase the impact as you run down the hill.)
Run the hill emphasizing lift off the ground. It's not as important to run fast up the hills as it is to run with good form and a powerful stride. Your heart rate should be at or near maximum when you reach the top of the hill.
After running up the hill, turn around and run down the hill. This is your recovery period, so run relaxed and allow your legs to stretch out. Allow gravity to carry you down the hill, don't accelerate when running down the hill - remember this is your recovery.

Hill Drills:

Hill drills are done at a slow pace. The goal is to get lift off the ground and not to move forward at a rapid pace. Your progress up the hill should be slow. It should take up to 6 minutes to reach the top of the hill. All drills should be performed SLOWLY!
Bounding: Elongate your stride and emphasize arm action. Focus on getting off the ground. Think of jumping over puddles with a long stride.
Skipping: Skip slowly up the hill, emphasizing knee lift and arm action. Focus on getting high off the ground.
Springing: Emphasize knee lift and getting high up off the ground. Don't emphasize forward movement. Think of jumping over logs.
The Strength Building phase should last for at least 6 weeks, but no more than 12 weeks.

Goals of The Strength Building Phase:

Build muscular strength.

·             Increase capillary beds.

·             Build mitochondria.

·             Improve lactate enzyme response.

·             Raise lactate threshold.

·             Maintain aerobic fitness.

·             Maintain and increase VO2max.

·             Maintain cardiovascular and muscular endurance.

·             Maintain base mileage and distance of long workouts.