BrassDragon
Member
What is the best way to build endurance for marathon?
I run 10 km 3-4 times a week and then do 20 km on last day.
Legs are very tired after that 20 km, and I can't even imagine what it's like to go for another twenty.
You're feeling burned out because you're crushing a lot of mileage in the run-up to your distance training, essentially running a weekly near-marathon piecemeal.
There is really no need for that - it's more effective to vary and stagger your training intensity. During the week, up the intensity by going faster for shorter distances. Try to find a weekly rhythm that goes something like:
Day 1: short jog
Day 2: tempo run for less half the distance on day 6
Day 3: Rest
Day 4: tempo run for less than half the distance on day 6
Day 5: Rest
Day 6: Distance run
So if we take your current estimates, it would look like:
Day 1: 5 kilometer jog (slower than comfortable for you)
Day 2: 8 kilometer tempo (breathing hard)
Day 3: Rest
Day 4: 8 kilometer tempo
Day 5: Rest
Day 6: 18 kilometers comfortable pace
Every 2-3 weeks, up those distances slightly. It's better to find an online calculator for an endurance training that suits your ability and age but chances are, it'll spit out a schedule that's patterned like the above.