Lifting and running: check your training week

How this works

The check runs over every pair of days you set and looks for one thing: a heavy leg session sitting close to a hard run.

Endurance work switches on AMPK. AMPK suppresses mTOR, the signal that turns a hard set into new muscle, and that suppression runs for about 24 hours before it clears. Same day is the worst version of it. Back to back costs you less. Two days apart and the two sessions never meet, which is why the check goes quiet at a two-day gap instead of telling you to do less.

Upper body never enters the arithmetic. In Wilson's pooled 21 studies the interference turned up when the sessions sat on the same or consecutive days and both of them loaded the same limbs. Both conditions had to hold. So upper-body days can land wherever they fit your week, and the tool leaves them alone.

There is a third and lighter check: heavy legs the day before a long run. That one is Formi's own call rather than a finding from either paper. Tired legs make a long run worse without doing much to the muscle you just built, so it weighs less than a hard-run clash.

What it can't see

One session per day. That is the shape of the form, and it hides the most severe case in the model underneath it. Legs in the morning and intervals the same evening score double what the same pair scores on back-to-back days, and there is no way to type that in here. If you already double up, this page will read your week as cleaner than it is.

When strength and running have to share a date anyway, lift first and run six to eight hours later. Hold that one loosely. It is reasoning drawn from the 24-hour window rather than something measured directly, which makes it the piece most likely to move as more work comes in.

Everything else about you is invisible here too. How hard your hard run actually was. How you slept, and what last week already took out of you. A week that comes back clear means these pairs do not collide. Whether it is the right week for you is a bigger question than this form asks.

Sources

Two papers do the work here.

Wilson JM et al. “Concurrent training: a meta-analysis examining interference of aerobic and resistance exercises.” J Strength Cond Res 26(8):2293–307, 2012.

Coffey VG, Hawley JA. “Concurrent exercise training: do opposites distract?” J Physiol 595(9):2883–96, 2017.

The long version of all this, including the number most people meet secondhand, is in the guide: lifting and running in the same week.

Checking one week takes a minute. Checking it again every time the week moves is the part people drop. Formi keeps that up for you, whatever you train. One coach. Every sport.