Day 24 after quitting smokingStairs

By Yevhenii, who smoked for 26 years · Updated 30 Oct 2026 · 2 min read

In shortCarbon monoxide is out of your blood, the airways are less irritated and the resting heart rate has dropped, so effort costs less. The change is gradual and easy to miss. Repeat your day-fourteen stairs or hill and compare.

What's happening in your body

Three things that limit effort have shifted since you stopped. Haemoglobin that was tied up carrying carbon monoxide now carries oxygen. The airways are less irritated and less narrowed than they were. And the resting heart rate has dropped by several beats a minute, a change that appears in the first days and persists. The NHS dates easier walking and running from the second week onward.

What to expect

The difference is easy to miss because it arrives gradually and nobody remembers exactly how breathless they used to be. That is what the note from day fourteen is for. Do not expect anything dramatic yet. The NHS places the bigger improvement in breathing between three and nine months, so what you notice now is the early part. If effort still brings unusual breathlessness, chest pain, or a cough that is getting worse rather than better, see a doctor, because those are not part of recovery.

Try this

Repeat the same stairs or the same hill, at the same pace, and compare how you feel at the top with what you wrote ten days ago.

What else you could do

If you did not write anything then, do it now and repeat in two weeks. Evidence that you collected is harder to argue with at eleven at night than any text. If you want a number rather than a feeling, note how long it takes to get your breath back at the top, and compare that next time.

Sources. NHS Better Health, Quit smoking. Hughes, 2007.