Training when you're sore: the DOMS decision tree

Day four of IGNITE and your quads hurt on the stairs. The question isn't philosophical — the plan says squat today, and you have to decide in the next ten minutes.

There's a real answer, and it isn't 'listen to your body'. That advice is useless at 6am because your body is saying two contradictory things at once.

What DOMS actually is

Delayed onset muscle soreness turns up twelve to twenty-four hours after unfamiliar work, peaks somewhere around the second day, and fades over the next few. It's driven by the lowering half of a lift — the eccentric portion — and by movements your body hasn't done recently.

It is not lactic acid. Lactate clears within about an hour of finishing, long before you're sore. It's also not a measure of how good the session was: you can train hard, progress well and feel almost nothing, especially by week three when the same session stops producing it at all. That fading is the repeated bout effect, and it's a sign of adaptation, not of going soft.

Which is why the first ten days of IGNITE produce most of the soreness you'll experience all month. Everything is new, the eccentric load is unfamiliar, and your body responds accordingly. By ACCELERATE it's largely gone even though the loads have gone up. If you judge your sessions by how sore you are the next day, the plan will look like it's getting easier at exactly the point it gets harder.

Soreness or pain — the first fork

Everything downstream depends on this, and the two feel different once you know what to compare. Soreness is diffuse, sits in the muscle belly, shows up on both sides roughly equally, and gets worse when you press it. Pain is sharp, points to a specific spot, often involves a joint, and doesn't care whether you press it or not.

• Both sides, muscle belly, dull and spread out, worse when you poke it — that's DOMS, keep reading
• One side only, or a joint rather than a muscle — stop and get it looked at
• Sharp, sudden, or it arrived during a set rather than the next morning — stop
• Swelling, a visible bruise, or a limb that won't take normal weight — that's a clinician's call today, not tomorrow
• Severe soreness with dark urine after an unusually brutal session is a medical situation, not a training one — go and be seen

The warm-up test

If it's soreness, you don't decide before the session. You decide four minutes into it. Do the warm-up as written, then take an honest read on the sore area.

Soreness that eases as you warm up is the normal kind and it will keep easing under load. Soreness that is exactly as bad after the warm-up as before it — or worse — is telling you the tissue hasn't finished recovering from last time.

This is why the decision belongs after the warm-up rather than in the kitchen. The version of you standing on the stairs at 6am has one data point and a strong opinion. The version four minutes into a warm-up has actually tested the thing. Most sessions people skip for soreness are skipped before that test happens, which means they were skipped on a guess.

The four outcomes

That leaves you with a short list, and one of them applies to almost every sore morning you'll have this month.

Train as written if the soreness is in a muscle group today's session doesn't target, or if it eased through the warm-up. This covers the large majority of cases, and it's the one people talk themselves out of.

Reduce load if it's still there after the warm-up. Take roughly twenty to thirty per cent off the bar and hold the prescribed reps. You keep the movement pattern, you keep the tick, and you keep tomorrow. Grinding a heavy set on a stiff muscle buys nothing that a lighter set doesn't.

“Soreness is information about the last session, not permission to skip the next one.”

When to swap, and when to stop

Swap to an Active Recovery day from the plan if soreness is everywhere at once, sleep was short, and everything feels heavier than the number on the bar says it should. Your plan already contains those days — you're moving one forward, not inventing a rest day. Walk your steps, hit your protein, keep the other five targets, and run today's session tomorrow.

Stop if it's the pain column above. That's not a training decision and no amount of warming up changes it.

• Different muscle group than today's session — train as written
• Eases through the warm-up — train as written
• Still there after the warm-up — cut load by twenty to thirty per cent, keep the reps
• Sore everywhere, short sleep, everything heavy — take an Active Recovery day from the plan and shift the session