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Lifting through a marathon block: what the science actually says

14 July 2026

You're ten weeks out. The long runs are climbing, every plan you've read says “add strength work” and then goes quiet on how — and half the internet still insists cardio kills gains. Most of what you've been told about that comes from one paper. It's worth knowing what happened when someone checked.

Where “interference” came from

In 1980, Robert Hickson had subjects train strength, endurance, or both, and found the combined group's strength gains stalled where the strength-only group's kept climbing. That result became the interference effect, and in 2012 a much-cited meta-analysis (Wilson and colleagues, in the Journal of Strength and Conditioning Research) appeared to settle it: concurrent endurance work blunted strength and muscle growth, running interfered more than cycling, and the damage scaled with frequency and duration. That paper is the reason every running forum has someone warning you that mileage eats muscle.

What the re-examination found

In 2022, a larger and more tightly controlled meta-analysis (Schumann and colleagues, in Sports Medicine) re-ran the question with a decade more data. The finding: adding aerobic training to lifting did not meaningfully compromise maximal strength or muscle growth. The measurable cost showed up in one place — explosive, power-type outputs. If your sport is jumping or sprinting, concurrent load deserves real care. If your goal is being strong and keeping your muscle through a marathon block, the classic interference story is far weaker than its reputation.

That doesn't mean combining them is free. It means the cost has been misattributed.

What high mileage actually costs

Two things, and neither is mysterious molecular sabotage.

Fatigue is one budget, not two. Your recovery doesn't keep separate accounts for “running tiredness” and “lifting tiredness”. A useful way to count the total is session-RPE load (Foster's method): minutes multiplied by how hard it felt, for everything you do. When the running side of that ledger climbs, something on the lifting side has to give — and it should be accessory volume first, not the heavy work that keeps you strong.

Eccentric damage is local and it lingers. Running — especially long, especially downhill — loads your posterior chain with thousands of braking contractions. That's tissue damage with a recovery cost measured in days, which is why heavy hinging the morning after a twenty-miler feels like betrayal. A bike ride of the same duration and effort doesn't do this, which is also why cyclists get away with concurrent training more easily than runners. The modality matters, not because of interference signalling, but because of what the tissue went through.

How to programme the week

  • Keep intensity, trade volume. When weekly mileage peaks, hold the heavy top sets on your main lifts and cut accessory leg volume. Strength is maintained by intensity; fatigue is driven by volume. Cut the cheap sets, keep the expensive ones.
  • Give the posterior chain 48 hours after the long run. No heavy hinging or squatting into freshly damaged hamstrings. Upper-body sessions slot in anywhere.
  • Separate hard from hard. If a quality run and a heavy lift must share a day, put hours between them and do the one that matters most for you first. Better: hard days hard, easy days easy.
  • Count everything in one currency. Minutes × effort, for every session, mat round and match included. When the weekly total spikes, that's the week to back the lifting off — not the week the calendar says so.
  • Never cut the rehab work. It's the cheapest insurance in the whole plan, and it's always the first thing people drop.

The honest summary

Lifting through a marathon block isn't just possible — done right, it's protective. The old fear was built on a finding that didn't hold up at scale; the real constraints are a shared fatigue budget and eccentric damage that needs time. Both are manageable with scheduling and restraint. What they demand is a plan that actually responds to your running week rather than pretending it isn't happening.

That last part is what Granite is: a strength coach that counts the rest of your week and rewrites your lifting around it. But whether or not you use it, count the cost by kind — fatigue and tissue, not folklore.

References

Hickson RC (1980), European Journal of Applied Physiology 45. · Wilson JM et al. (2012), Journal of Strength and Conditioning Research 26(8). · Schumann M et al. (2022), Sports Medicine 52. · Foster C et al. (2001), Journal of Strength and Conditioning Research 15(1).