Uploaded June 2026 | Updated September 2026, 1 week ago
Your body adapts to running differently over time.
📈 In the first few weeks, you see rapid changes including a 10–20% expansion in blood plasma volume, improving venous return, stroke volume, and oxygen delivery.
Over the first 6–12 months, your heart gradually adapts, particularly the left ventricle, and your muscles increase capillary density by roughly 20–25%.
📊 But after that first year, many of the big base cardiovascular adaptations start to plateau.
So how do experienced runners keep improving in years 3, 4, 5 and beyond?
Primarily:
1️⃣ Running economy
2️⃣ Lactate threshold
Lading to an ability to sustain higher workloads for longer
🏃🏽♂️ Running economy can be supported with things like skipping drills, extensive plyometrics, and controlled strength training that improves stiffness, posture, and force transfer.
Lactate threshold is then built on top of your aerobic base with more specific sessions like tempo runs or threshold intervals.
🔑 Knowing the time course of these adaptations allows you to program more sensibly given the experience and training status of your athletes.
Your body adapts to running differently over time.
📈 In the first few weeks, you see rapid changes including a 10–20% expansion in blood plasma volume, improving venous return, stroke volume, and oxygen delivery.
Over the first 6–12 months, your heart gradually adapts, particularly the left ventricle, and your muscles increase capillary density by roughly 20–25%.
📊 But after that first year, many of the big base cardiovascular adaptations start to plateau.
So how do experienced runners keep improving in years 3, 4, 5 and beyond?
Primarily:
1️⃣ Running economy
2️⃣ Lactate threshold
Lading to an ability to sustain higher workloads for longer
🏃🏽♂️ Running economy can be supported with things like skipping drills, extensive plyometrics, and controlled strength training that improves stiffness, posture, and force transfer.
Lactate threshold is then built on top of your aerobic base with more specific sessions like tempo runs or threshold intervals.
🔑 Knowing the time course of these adaptations allows you to program more sensibly given the experience and training status of your athletes.
