Updated: September 22nd, 2023
How your mind and body change in the middle of a run: Miles 3-4.

By now you’re well on your way. You’ve decided both mind and body are prepared to hit five miles. Nothing here plateaus though, unless you fancy a rather boring run…

Your body will react to different challenges you’re putting it through – gradients, obstacles, type of training you’re doing (intervals, threshold, fartlek or continuously trotting on).

It’s the middle of the run where you can play with challenging and conditioning your body – hit the hills to impact those legs (that’s both up AND down hills to target different muscles), or head to the trails and test your balance, co-ordination (yes there’s bound to be some hurdling tree branches) and core stability.

Male runner in the city running up hills

What is happening physiologically?

Again, depending on the type of terrain, the weather and the training you do will dictate how your body will react physically throughout this mid-section.

  • Interval training – Periods of work followed by periods of rest.
  • Very much like you felt in the initial mile will be on repeat here. Intervals are designed to push your body to its maximum and then allow it to rest before spiking it up again. Often these work periods are 30 seconds to a minute and then, from 30 seconds to two minutes rest – either walking or slow recovery jogging to bring both heart and breathing rate back down to a restful state.

  • Fartlek training – Speed play.
  • Fartlek is fun to run to how you feel. Like interval but with less structure. So feeling this run is a bit boring and slow? Spike up the heart rate and run like Phoebe in friends! (“Like a kid because that’s the only way it is fun”) and then slow to a walk until the lamppost and then jog again until you pass three red cars. – it is mentally more fun, but not often used for elite runners who want to measure performance.

Woman tying her running shoes ready to train

Whatever training you are doing, note that running on the trails is much harder for your body than running on the tarmac.

Your stabilising muscles are working extra hard to keep your ankles from rolling, your calf muscles are pushing harder to deal with slippy mud. More often than not you’re jumping over tree roots or fallen branches. And the hills with an uneven, loose stone terrain will test your muscles, courage and balance!

To run uphill it’s no secret that it requires extra effort, from your glutes, hamstrings and calf muscles, but also heart, lungs and mind. It will be tougher the longer it goes on. Shorter concentric contractions from the triple extension of hip, knee and ankle to propel you up the hill will inevitably cause soreness tomorrow. But what’s worse? Downhill!

Mountain runner jumping at the top of the hill

Going downhill on tarmac, you can trust your foot placement and the even-ness of the terrain. On trails, you are not so lucky. They are usually much steeper than roads, and much less forgiving.

Running downhill requires your quad muscles to both contract and lengthen (eccentric contraction). It contracts (shortens) to land your heel on the floor and then lengthens to step forward BUT it must do so carefully. Eccentric contraction is hard on the body. You’re asking a muscle to get longer and still stay under tension. So while choosing the uphill might seem more of a challenge, you will be in more pain post-run with downhill DOMS (delayed onset of muscle soreness).

What is happening mentally?

Your mental motivation will dictate a lot of this mid-section of the run. Are you willing to tackle that hill? Or work harder in those sprints? What route are you taking? (And thus avoiding the difficult option?).

Your mind gives up way way way before your body does (take it from me, I ran 10 marathons in 10 days and my body was ..erm.. fine?) So don’t let your mind trick you into easing off when you need to work. Equally, don’t let it tell you to work when you need to ease off – it’s all about building mental toughness, trusting and being kind to yourself.

All of which are built here, in this mid-section of each run you take…

Let’s see what happens during the last miles and cooldown!

Man resting in a tree

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