Running long distances requires training your body so you can keep going mile after mile. While your mental motivation matters, there’s also science behind building physical endurance. This article explains the basics and key strategies any runner can use to boost their endurance. 

  

Aerobic vs Anaerobic   

Long-distance running mainly uses your aerobic energy system, which requires oxygen. Anaerobic gives you short intense bursts without oxygen. Focus training on improving your aerobic system by running more miles. Mixing in some faster anaerobic running is also helpful. 

  

Boost Your Cardio Fitness 

VO2 max measures your cardiovascular fitness – how well your heart and lungs deliver oxygen to your muscles during exercise. Train at 65-85% of your maximum heart rate for 20-60 minutes multiple times a week to increase VO2 max. Intervals of hard running with jogging recoveries also help. Better cardio fitness provides more oxygen for your muscles over long distances. 

  

Lift Your Lactate Threshold  

Lactate threshold is when lactic acid rapidly starts building up in your muscles, making you fatigue quicker. Tempo runs and certain workouts raise your threshold, enabling you to run at a faster pace before fatiguing. This expands your range of sustainable speeds. 

  

Improve Running Economy  

Running economy is how efficiently your body uses oxygen at a given speed. Better economy means running faster with less effort. Drills, strength training, and hill sprints can enhance your running form and coordination to stride more efficiently. 

  

Grow More Mitochondria 

Mitochondria give your muscles aerobic energy. Long, slow runs signal your muscles to produce more mitochondria. Having more mitochondria allows your muscles to keep aerobically generating energy without tiring. 

  

Increase Capillaries  

Capillaries are small blood vessels that deliver oxygen. More capillaries around muscle fibers improve oxygen supply via better blood flow. High-mileage training expands your capillary network, boosting endurance. Greater capillary density sustains your pace longer. 

 

Build Slow-Twitch Muscles  

Training shapes your muscles for endurance, like increasing slow-twitch fibers. Slow-twitch contract slower but resist fatigue better. Running more miles develops muscles that are more aerobic and fatigue resistant. 

  

Handle Heat Better  

Running makes a lot of heat. You need to be able to dissipate heat to sustain your pace. Heat adaptation training helps your cardiovascular system cool yourself better. Staying hydrated also regulates your temperature. Overheating really slows you down. 

  

Fuel Effectively 

You need adequate carbs and fat stores for energy during long distances. Refueling before, during and after runs helps maintain blood sugar and replaces used carb stores so you don’t hit the wall. Running more weekly also teaches your body to tap into fat better, saving your carbs. 

  

Balance Hard & Easy 

Training right means balancing hard days that push you with easier days for rest and adaptation. Not enough rest can lead to overtraining. Allowing proper recovery between tough sessions helps you maintain fitness gains. 

  

Conclusion 

Knowing the physiology behind long-distance running allows you to train smarter. Focus on improving your cardio fitness, economy, lactate threshold, muscles, heat handling, fueling, and recovery. Blend harder and easier days. Use science-based training to build your endurance.