For a lot of runners, the idea of doubling—running twice in one day—sounds like something only elites do. But it’s not just for professionals logging 100-mile weeks. There are plenty of good reasons to split up your runs, and if you do it strategically, it can boost your training without burning you out.
Why Run Twice a Day?
Adding a second run isn’t about grinding yourself into the ground. It’s about using smart training to get more out of your miles. Here’s when it makes sense:
1. Building Volume Without Overload
If you’re trying to increase your weekly mileage, doubling can be a way to add volume without making a single run excessively long. Instead of jumping straight from 8-mile runs to 12-mile runs, you could do 8 miles in the morning and 4 miles in the evening. That extra mileage adds up over the week but feels more manageable.
2. Faster Recovery
A second, easy run can act as active recovery, helping flush out metabolic waste, boost circulation, and reduce muscle soreness. This is especially useful after a hard session or a long run.
3. Training on Tired Legs
Marathoners and ultra runners sometimes use doubles to simulate late-race fatigue. If you do an easy morning run and a moderate evening run, that second session mimics the feeling of running on tired legs without requiring a single brutal long run.
4. Glycogen-Depleted Running
If you do a morning run before breakfast and another later in the day, the second run is a low-glycogen effort. This helps train the body to use fat more efficiently as fuel, which can be a valuable adaptation for long-distance runners.
5. Prepping for Multi-Day Events
If you’re training for something like a stage race, relay event, or back-to-back race days, doubles help simulate the demands of running when you're not fully recovered.
6. Fitting Running Into a Busy Schedule
Sometimes life doesn’t allow for a single long run. If you’re short on time, splitting up a run can be the difference between getting the miles in or skipping them altogether.
When to Skip Doubles
Not every runner needs to add a second run, and in some cases, it can do more harm than good. If you’re dealing with any of the following, it’s best to hold off:
-
Lack of Recovery – If you’re struggling with fatigue, soreness, or poor sleep, adding a second run can dig a deeper hole. Recovery should always come first.
-
Low Weekly Mileage – If you’re running fewer than 40 miles per week, your time is probably better spent making your single runs more efficient.
-
Neglecting Strength Training – Don’t replace strength work or mobility work with extra miles. Stronger runners are more durable runners.
-
Forcing It Just to Hit a Number – Doubling just to chase mileage isn’t smart training. Every run should have a purpose.
How to Add Doubles to Your Training
If you’re ready to add a second run, start small. Try an easy 20–30-minute shakeout in the morning before a quality workout in the evening. Or add a short evening run to your schedule once a week and see how your body responds. Pay attention to your recovery, sleep, and overall energy levels. If you feel good, you can gradually increase frequency.
Running twice a day isn’t just for elites. It’s a tool that can help you safely increase mileage, speed up recovery, and prepare for race-day demands. The key is knowing when and why to use it—and making sure it supports your overall training, rather than just piling on extra miles for the sake of it.