Some lofty claims were made about the importance of wearing the right footwear to go fast following Nike’s ‘Breaking2’ marathon project. But a 2016 study from the Medicine & Science in Sports & Exercise journal may go some way to supporting the claims.
The study saw 18 male sub-20min 5km runners complete treadmill tests and three 3,000m time trials wearing control shoes, then identical shoes with 100g and 300g of covertly added mass.
The results showed that even though the runners had no idea they were wearing heavier shoes in the second and third time trials, they ran between 0.65% and 1.36% slower in the shoes that were 100g heavier and between 2.09% and 2.37% slower in the shoes that were 300g heavier.
Of course, few triathletes are training to run 3,000m, and very light shoes may give you diminishing returns when your legs start to fatigue over longer distances. So find a good gait analysis and only go for minimalist running shoes for race day if your biomechanics will allow, based on the recommendation of a shoe fitter or experienced running coach.