Why you should consider racing a half marathon close to your marathon

Aside from being good for confidence, racing a half marathon a few weeks prior to your marathon gives you the chance to gauge your progress. If you haven’t raced during the previous 2-3 months of marathon training, it can be harder to notice the progress you’re making, but racing will bring out your best, leaving you with a better idea of where you are in relation to your goals.

Riegel’s formula allows you to take a recent race time and distance to predict your time for another distance. For instance, if you run 1:45 for your half marathon, you’re predicted a 3:39 marathon. It’s not a perfect tool as it can’t account for all the other factors such weather, course difficulty and the various training factors that will impact your time, but it’s a good starting point.

Obviously it depends when your marathon is and the availability of a half marathon in the weeks before. It also depends on the length of your taper, but I’d suggest racing 1-2 weeks before you start tapering. I.e. if you’re tapering for 3 weeks, race 4-5 weeks prior to your marathon. It’s close enough to be a good indicator of fitness and the pace you should aim for by working with your result from Riegel’s formula, but gives you enough recovery time without the risk of injury being too much of a concern.

After the race reflect on your performance. What does it suggest you could run for the marathon distance and are you happy with that? How does that sit with your initial target and training to this point and what can you learn from it for future use? How does the course for your half compare to the course for your marathon when it comes to elevation gain?

By knowing these things, you can more accurately plan the final elements for your marathon day and have the potential to squeeze another few seconds, or even minutes, from your performance when it matters most.