The long run is an important part of any training program. Not only does it help you build endurance, but it also prepares you mentally for race day by teaching you how to stay focused over a long period of time and giving you confidence in knowing that you can complete the distance. But how long should your long run be? That, of course, depends on what distance you’re training for, but there are a few general rules to help guide you in the right direction.
An easy way to determine how far you should go on your long run day is by basing it off of a regular mileage day. The general rule of thumb is that your long run should be one and a half to two times as long as your normal-length run. For example, if you typically go out for 30 minutes on your easy run day, your long run should be 45 to 60 minutes long. In distance terms, if you normally run 5K on your easy days, your long run should be 7.5K to 10K in length.
You can also use your total weekly mileage to determine an appropriate long run distance. Your longest run should be about 20 to 30 percent of your total mileage for the week, so if you run 50 kilometres in a week, your long run should be about 10 to 15K.
There are a few other factors that will affect how long your long run should be, including your training age and the distance you’re training to run. Runners who have been racing and training for a number of years will most likely be able to run longer than newer runners, and so they can increase the distance of their longest run. Beginners should stick to the lower end of the distance range in order to avoid overtraining and injury. Of course, your long run needs to prepare you for the distance you will be racing and so the distance should reflect that. For example, if you’re training for a half-marathon, a 45-minute long run will likely not be enough to prepare you for the race.
When you’re training for a longer race, you shouldn’t try to do your longest run right away, nor should you be running your longest distance every week. Instead, you should gradually increase your distance over a number of weeks so that you can work up to the longer distance without injuring yourself. Most training plans for longer distances will have you gradually increasing until you reach your longest long run, then tapering back down as you approach race day. Conversely, a training plan for a shorter distance, like a 5K, will typically have you gradually scale back your long run to make more room for speedwork.
As for pacing, your long run should be done at an easy, conversational pace. For slower runners who race close to their training pace, that is likely about 30 seconds to one minute per kilometre slower than your race pace. For faster or more experienced runners, your long run may be up to 1:30 per kilometre slower than race pace.
The bottom line
In summary, when you’re trying to figure out how long your long run should be, you need to consider your training experience, how much you’re currently running, and what distance you’re training for. If you’re moving up in distance, it’s important to gradually increase your weekly mileage (including your long run) over a number of weeks in order to avoid injury. There are many different opinions out there as to how long your long run needs to be, but if you’re really serious about training, your best bet is to get a coach who can create a periodized program for you that will prepare you for race day while avoiding common training pitfalls that often lead to injury.