Running twice a day (sometimes referred to as “doubles”), is a method used in the running world to increase volume, reduce recovery time, and bring more energy/focus to each training session. With running being over half a HYROX for most athletes, could including “doubles” in your training be key to unlocking your next PB?
Potential Benefits to HYROX Athletes
Added Volume
Since the 1950s, most scientists, coaches and athletes have agreed that a consistent high volume of training is the foundation for success in endurance sports (1).
If you look at plans by some of the world’s most respected running coaches such as Jack Daniels, Hal Higdon, Greg McMillan or Pete Pfitzinger, you will find that they’re all fairly similar. Their plans will typically feature 2 quality runs (e.g. a threshold and interval session), a longer easy-paced run, and then everything else will be easy-paced. You’ve probably heard of the 80/20 split: roughly 80% of your training volume is easy, 20% is hard. These coaches typically follow this approach pretty closely.
The reasoning behind this is that most athletes can only put true intensity into their training so often without getting burnt out or injured. However, most can build their bodies to handle a huge amount of easy training.
As you begin building your easy mileage, your body will slowly improve its ability to utilise its various energy sources – primarily fats and oxygen – whilst clearing lactate – through improved mitochondrial density, fat oxidation and enhanced capillary density (2).
For many runners, there comes a time when even your easy runs begin feeling too long. Perhaps you are getting tired during the run, not recovering before your next run, or end up losing focus and find your form is getting sloppy. There can also be an increased injury risk by running too far in a single session.
There are certainly trainers who will suggest that pushing through this (both physically and mentally) will bring about some of the improvements you are seeking. And many more would argue that a single run of 10km is better than two runs of 5km. This is because physiologically, once you pass that ‘beginner’ phase of running, there is a certain amount of work required to stimulate adaptations. However, what about two runs at 7km vs one run at 10km? So 14km in a day vs 10km in a day. What if the two runs at 7km are done with better running form and leave you feeling fresher for your ‘quality’ 10 * 400m session the next day, despite having run an extra 4km the day before?
Improved Ability to Recover and Adapt
Here’s how doubles may not only reduce your injury risk, but improve your recovery:
- Splitting training volume across two sessions reduces the acute stress and load placed on the body in each session. Ultimately, this lowers the risk of overuse injuries.
- Shorter workouts also promote increased blood flow, aiding removal of metabolic waste and delivering nutrients to muscle tissues, which could see each run kickstarting the recovery process; especially true with low intensity running.
- Spacing workouts can give you a double hit of hormonal responses, such as the release of growth hormone and cortisol levels, which play a critical role in recovery and adaptation. Balanced hormonal cycles contribute to better muscle repair and reduced injury risk.
- By splitting sessions, we can refuel and replenish glycogen stores between workouts, which supports sustained performance and better recovery. This is especially useful if you’re someone who finds themselves feeling tired about three-quarters into your usual run or that your form gets a little sloppy as your legs begin to feel heavy.
- With HYROX specifically, we can play around with using double running days to give us full days of recovery to certain muscle groups. For example, rather than pounding the legs every day such as:Monday: Run & Ski Intervals
Tuesday: Run & Upper Body liftingWe can experiment with hitting the legs with our running one day then hitting the upper body the next:
Monday: Run & Run
Tuesday: Upper Body Lifting & Ski Intervals
Improved Engagement
If you are newer to running, it’s likely that your running form isn’t yet perfect. Like rowing or skiing or wall balls, there are elements of your running technique that you can work on to bring about improvement.
Just like any skill, ‘perfect practice makes perfect’ and with human attention spans being limited to around 20-30 minutes, practicing perfectly for longer than that gets increasingly difficult.
We ‘can’ run with bad form, but that doesn’t mean we should. Shorter sessions where we focus more on our technique, without letting bad habits creep in, could be beneficial to your running economy.
Mentally Manageable
Running for an hour or more can be mentally challenging for many people. Instead of pushing through a single long run of 10-16 km, breaking it into two shorter runs of 6-8 km each can make it mentally easier while still increasing your total running.
Potential Drawbacks to HYROX athletes?
Available Time
Running twice a day can be an increased time commitment – especially once you take in to account the (potentially) increased volume, warm up / cool downs, getting ready, showering, etc!
You may have a family, job, etc that makes training twice a day difficult to impossible. If this is you: remember that you can still improve significantly by running once a day even just a few times a week. This is just one method of training!
Overtraining and Injury Still Possible
While running twice a day can be a good way to increase running mileage with a reduced risk of injury, there is still always some risk of injury when running more. As with any volume increase, be careful to increase your miles gradually, and be sure to keep strength training in your training programme.
Mental Fatigue
One of the great things about HYROX as a sport is that it allows you to have a varied training plan. One day you might be running, the next lifting a heavy deadlift from the floor, the next doing a metcon that sees you moving between burpees and wallballs. Running doubles can reduce this feeling of variety and, depending on your goals and what you enjoy, leave you feeling burnt out on running or bored.
How to Incorporate Double Days For HYROX
If you think doubles could be for you, then there are a few ways you could add them into your week. You could go with:
- An Easy-Easy approach, where you simply do just over half your easy run distance twice (e.g. a 10km run becomes two 7km runs).
- A Hard-Easy approach, where you do your Threshold/Interval session in the morning and then follow it up with an easy mileage session in the evening to add to your overall volume (e.g. 10*400m in the morning, 7km in the evening).
- Or, if you are a more advanced athlete, you could research the Norwegian method of ‘double threshold’ training, where you essentially take a Medium-Medium approach (e.g. 3-5 * 6 minutes @ RPE 6 in the morning, followed by 8-10 * 400m @ RPE 7 in the evening).
- Varying weeks. In this case, you may consider running shorter doubles one week and then longer singles the next. This can really help keep training interesting by ensuring each week offers a new challenge rather than simply being a progression over the previous week or help break through mental barriers.
Whatever you choose should depend on your abilities, goals, time availability, preferences, running history, injury susceptibility and more.
Should you use Doubles?
Whether you are a high-level runner, beginner runner or HYROX athlete, adding volume is a scientifically proven way to improve your performance. Including doubles is one way to achieve this that can offer a range of additional benefits too.
However, it’s important to recognize the potential drawbacks and to ensure that your nutrition – especially your calorie intake and electrolytes – match your increased workload.
With thoughtful planning and progression, HYROX athletes can certainly use doubles to break plateaus and set new PRs in both running and HYROX races.
