How your body and mind change on a run: The last stretch into the final mile & cool down.
The fourth in the serie

Heading home from your 5-mile run can feel like the longest stretch and some runners will often use it as the cooldown.
By this point, fatigue will be present in the legs and is due to the increase in lactic acid and not due to energy depletion.
Even on the toughest of five-mile routes, total energy expenditure sits under 700 calories – which is way below the body’s total glycogen storage levels (the energy from carbohydrate breakdown) so energy depletion should not be an issue here, although you may still feel tired.
If you’re aiming for a PB then I wouldn’t use the final mile as a cooldown, for obvious timing reasons. So power through for the full five miles and add an extra 5-10 minutes for your cool down.
But if you’re not aiming for a PB it is a good idea to use the final mile as a cool down, start the process of bringing your body back down to a relaxed state. Steady your breathing, and slow the pace down so your final few steps are at a walk.
It has been a tough 4 miles so far and no doubt there will be some dehydration. Remember sweat is the preferred way for the body to cool down, thus releasing fluid onto the surface of the skin will impact hydration levels. If your run has taken you 40-50 minutes, an estimated one to two litres of sweat will have evaporated from the body and needs to be replaced as soon as possible.
Chasing that feel-good factor? You’re in luck! A run that lasts at least 45 minutes will leave you with the runners high. The feel-good endorphins release just as you’re finishing up and will stay for a good few hours. You earned it!
Just because you have physically stopped running, doesn’t mean your body has stopped working so hard. It takes time for your body temperature to re-regulate – some runners, like myself, get cold instantly and need to warm back up, others are warmer for longer and need extra time to cool down (both are okay!)
Breathing and heart rate will also slowly decline but it may take a good 5 minutes to feel relaxed. In the meantime, it’s a perfect opportunity to stretch. Your muscles will still be warm and supple so maximise your recovery by a few easy, slow, long stretches. Remember to take on fluids as you do so, rehydration should take priority.
Delayed onset of muscle soreness (DOMs) is that muscle ache you feel a day or two after a tough or, longer than usual, run. Essentially, to build stronger muscles there has to be an element of damage. Muscle fibres get broken down (the aches painful part) but will rebuild with adequate rest and recovery. But you can take the sting out of DOMs from the moment you finish your run.
No doubt your mind wonders during a cool down. You’re either thinking about what you need to do next, or what you left behind to run today. But stay in the zone if you can. Running is a sacred space for your physical and mental health.
You may find the time away and endorphin release presents you with a whole new outlook or solution to something troubling you. I always find a run that can put the world to right.
Have you checked your watch all around the route today? If you have found this run difficult, there’s scientific evidence of increased motivation if you’re getting constant physical feedback, but tread carefully here… There is a real risk of data overload, which can steal joy from running. Comparing your performances, times and mile splits, especially when you’re training to compete. If you are one of those runners who loves data analysis then by all means check but do it at home after.
So, there we have it, a full five-mile run, broken down into mile segments, displaying how your body, mentally and physiologically, changes and adapts from the initial thought of grabbing your running shoes, into the first mile, how things change as you head into the second. The third and fourth-mile challenges you put on yourself and then, finally, the last stretch back home.
Happy running!