Just like stressing your body in training leads to gains in strength and endurance (and thus performance), stressing your mind during your workout can benefit you. Granted, you can’t substitute mental training for physical training – your mind is often a performance limiter, assuming you haven’t already met your actual physical limits.
For example, when your calves are screaming at you to the point that you physically can’t toe-off the ground any faster, you’ve run into a physical limitation best solved by work in the gym. But when your muscles have even a little juice left in them and you’re falling off pace – or into the same-old pace where you seem to have plateaued for weeks, months, years – training against mental fatigue may help.
Consider this: cumulative stress, distraction, and cognitive demands can cause you to struggle through a subsequent workout, and it’s not because you’ve exhausted your body. Perhaps you’ve noticed that your key run feels noticeably harder after a long day at work – there’s a reason, and it’s in your brain.
This “long day at work” effect was reproduced in the lab as early as 2009, when exercise physiologist Samuele Marcora’s group showed that mental fatigue from a 90 minute, highly demanding cognitive task caused subjects to max out their perceived effort faster and disengage earlier during a “cycling to exhaustion” task. In short, if your brain gets tired early, your body quits early.
“Well %^#&,” you might be thinking. “I better quit my job and move to a cabin in the woods with nothing but my trainer, bike, and an endless pool, such that I can minimize the demands on my brain and thus maximize my physical performance.”
There are a couple of problems with this proposition. First, it’s probably not realistic. Even if we remove the cabin-in-the-woods scenario, reducing your stress level is great, but you’re never going to remove every single cognitively demanding or stressful task from your day. Nor should you want to.
The key here isn’t getting rid of everything that is mentally fatiguing, it’s making the mentally fatiguing things less…fatiguing. You can actually work on pushing out that time-point at which your brain quits. And even better, you can do it while you exercise.
1. The pre-workout brain training method:
This would seek to emulate Marcora’s study referenced above. Sit yourself down in front of your computer, phone, or tablet and pull up one of the classic cognitive neuroscience tasks – I recommend the Stroop, Flanker, or Attention Network Task. Play for 5 to 90 minutes – you’ll know when you’re tired. Your mind will start to wander and you’ll get frustrated, even if selecting the right answers would still be “easy”.
This is the same thing that happens mid-race when your brain wants to quit and move on to the next new, shiny thing. Now immediately go out and run/swim/bike. It’ll probably seem harder than if you had done the same session without the cognitive task first.
2. The intra-workout training method:
Great for the time-pressed, and possibly even more beneficial – although we don’t really know yet (no published studies to date), many have speculated that simultaneous physical + mental training could be even more effective, since it more specifically replicates reality. Of course, this requires that you be somewhere with easy access to your tech – the Attention Network Task on a tablet during a trainer ride is a personal favorite (watch me below), but you can also put your mental training in during rest intervals if you’re out on the track or in the pool (grab your phone from the deck/sidelines).
If you’re intrigued, just keep a few things in mind. Training in a mentally tired state is stressful, so treat it like you would any other stressor you throw at your body to produce an adaptation – e.g. fasted sessions, post-strength work –start as small as you need to and build up, and consider where you insert these sessions into your training schedule (obviously, not on a recovery day).