Having a workplace ‘uniform’ – Facebook CEO Mark Zuckerberg’s grey T-shirt and hoodie, for example – is common practice among busy, highperforming people. Why? According to a theory proposed by psychologist Dr Roy Baumeister, we have a limited reservoir of mental energy to use on any given day. Initial research on this theory focused on self-control – how resisting temptations early in the day makes us more likely to give in later – but scientists soon learned that making decisions also wears us out. Experiments found that people who were asked to choose between consumer goods (eg, colour of T-shirt, brand of shampoo) performed worse than those who were presented with only one option on subsequent tests of everything from physical stamina to persistence to problem-solving. The researchers concluded that even when it comes to simple things, “making many decisions leaves a person in a depleted state”. APPLY IT If you can, work with a coach. You won’t burn energy planning or scheduling your training – you can shut off your brain and just do the workouts. Even though both of us (Brad and Steve) know a lot about running, when we’re training hard, we work with coaches for this reason. The night before your goal marathon, lay out your gear, commit to a plan for when you’ll depart (and where you’ll park), and have a pre- race meal ready. Automate as much of your training and race day as possible to conserve mental energy for running your fastest.