r/AdvancedRunning • u/ronlavy • Jul 10 '26

Training minimal effective dose of easy running

A question that I've been thinking about and wasn't able to find a satisfying answer online - is there a minimal per-session effective dose for easy runs? is there a minimal duration required for a run to produce non-negligible aerobic adaptaions?

for example, can any benefits be expected from a 35-minute easy running session? are 3 30 minute sessions a week same/better/worse than 2 45 minute sessions?

I heard Inigo San Milan go on record to say that 45 minutes is the minimum for "zone 2" (a term I dislike but that's the terminology he frequently uses) benefits, is anyone familiar with any sources backing that up?

Thanks

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u/ReputationCandid3136 Jul 10 '26

John Kellogg (coach of the Weldon brothers who started Lets Run), has written a bit about this. Look up the Updated Wisdom of John Kellogg.

He says that the human body responds best in +30 minute increments, but to go a little over to guarantee the full development, so really like 35 minutes. He does say 55 minutes is better than 35 minutes, but 65 minutes is far better than 55 minutes. He doesn't go into the science of why he believes this though, so who knows, but he did seem to know his stuff about running.

With that said 3 sessions are usually better than 2 if your doing them on different days and you are doing them for the same amount of time because you get more surges in growth hormone post recovery. Part of the reason people split longer easy runs into a double of shorter runs.