Doubles

What is a Double?

A double is having two running or biking sessions in a day. They are usually two easy efforts but some advanced athletes like 1500m Olympic Champion Jakob Ingebrigsten incorporate speed session doubles in their training. Doubles are typically done 4-6 hours apart: one session in the morning and one in the afternoon, or one afternoon session and one night session.

Benefits of Doubling:

Training for endurance sports like running and biking requires a lot of easy aerobic training. Easy runs and bikes are at an easy, conversational pace. The purpose of this training is for an athlete to build up a great aerobic base to then sharpen with speed training. Generally, the more time spent using this training, the more fitness you gain. An athlete can’t just go and do unlimited easy mileage since the chances of injury increase the more time spent training.

Doubling can help athletes hit higher mileage and time training without as high an injury risk. High mileage weeks eventually become too stressful for athletes and they’ll break down. A 100-mile week is very hard to run by only doing singles. That means running a 14-mile run every day of the week. A single 14-mile run will be very tiring for an athlete so sometimes it can be split into a double. Two 7-mile runs at different times of the same day will allow a runner to rest between runs and recover enough to have a quality second run. The body will be more recovered and will likely be properly fueled by food consumed between the runs.

On a second run, athletes are able to run or bike at a faster pace since they are more rested and this can help them be more in touch with speed. Long single runs will demand a slower pace and too many such runs can make an athlete slow although they’ll have endurance.

A double can also be easier on the mind. Approaching 2 five-mile runs isn’t as intimidating as doing a 10-mile long run.

hGH:

Exercise that lasts for a minimum of 10 minutes can induce the secretion of human growth hormone (hGH). This hormone is responsible for the growth and repair of muscle, bone, and collagen. By doubling, there will be two spikes of hGH production in the body possibly leading to higher recovery and quicker adaptation to running. Exercise at an intensity above the lactic threshold is most effective in stimulating the secretion of hGH but easy running can still induce the release of hGH.

Drawbacks of Doubles:

They are not for people just getting into running. Beginners should be focusing on running consistently throughout the week and shouldn’t be trying to immediately hit high mileage numbers since they will be very likely to get injured.

Even for advanced runners, doubles shouldn’t replace a quality long run in the weekly schedule. Doubles aren’t able to tap into the same energy systems as the long run due to the difference in length.

Doubles can be very mentally draining since it means you have to run multiple times a day. Running and grinding high mileage can become monotonous. The possibility of burnout is very real and athletes who want to utilize this training method should be driven and mentally prepared.

Sources:

GP;, Godfrey RJ;Madgwick Z;Whyte. “The Exercise-Induced Growth Hormone Response in Athletes.” Sports Medicine (Auckland, N.Z.), U.S. National Library of Medicine, pubmed.ncbi.nlm.nih.gov/12797841/#:~:text=An%20exercise%20intensity%20above%20lactate,increasing%2024%2Dhour%20hGH%20secretion. Accessed 9 Apr. 2024.

Barker, Sarah. “How (and Why) to Do Double Workout Days.” Triathlete, 13 Apr. 2022, www.triathlete.com/training/how-to-nail-double-workout-days/.

Reyna, Sarah. “Running Twice a Day: 6 Pros and 5 Cons of Running Doubles.” Marathon Handbook, 4 Oct. 2023, marathonhandbook.com/running-twice-a-day/.

Magness, Steve. “Evidence for Doubling, Training in Glycogen Depleted State.” Science of Running, 18 Nov. 2016, www.scienceofrunning.com/2009/11/evidence-for-doubling-training-in.html?v=47e5dceea252.