Endurance Training Plan (Week 4) – Learn to Suffer Smartly

In the third week, he trained his VO2max—the maximum rate at which the body can process oxygen. In the fourth week, he’s training another, equally important ability: the lactate threshold —the pace you can maintain just below the point where lactate begins to accumulate faster than your body can break it down. For 10K and half-marathon performance, the lactate threshold is often even more important than VO2max, because it determines the pace you can maintain over the long term—not just for a few minutes.

While the intervals from Week 3 were short and intense with incomplete recovery, threshold pace training is longer, continuous, or in long stretches with minimal rest —and subjectively, it should feel like a “comfortably uncomfortable” pace that you could maintain for about an hour in a race, but not much longer.

Strategy for Week 4: Pace runs replace intervals

• 4 out of 5 days remain in Zones 1–2 —the 80/20 principle applies unchanged.
• 1 day = threshold-pace training —either continuous tempo running or so-called cruise intervals (longer segments with a short break).
• The volume of the long run reaches a local maximum this week before the next phase of the training block.
• Strength training continues —this is the last week before the intensity of high-quality workouts increases further, so strength training remains at a maintenance level.

Nutrition and Recovery: Supporting Endurance Performance

The threshold is physiologically demanding on the body’s ability to effectively break down and recycle lactate.

• L-Citrulline — promotes blood flow to working muscles and may improve tolerance for longer runs at the threshold.
• Electrolytes — during longer tempo workouts and as long-distance running volume increases, they help maintain hydration and mineral balance.

What to Expect Next

Week 5 concludes the polarization phase of the training block—combining intervals and tempo elements in a single workout that’s more demanding than anything you’ve experienced so far. It’s the final step before your training shifts to specific preparation for your target race.