Get Back to Training After the Flu

Q  I’m training for a marathon (which is in three months) and I just came down with the flu. I’m worried because I’ve been in bed for three solid days, and I missed four days of training. How do I catch up with my training plan?



A  The good news is you still have plenty of time to prepare for your marathon. The trick is to avoid thinking about catching up with your training. Since Plan A is out the window at this point, it’s best to focus on a solid Plan B for the rest of the season.

Doing so will allow you to avoid the stress of trying to catch up to a training plan that can put you at risk for getting hurt from jumping back in too soon. Every training plan is a template that can be modified based on the happenings in your life.

The first step is to recover from the flu. Once the fever breaks, your body is on the mend. That doesn’t mean you should head out for a run the next day (you’re still healing); it simply means you’re on your way to better health in the next few days.

Because the flu knocks you on your butt, you’ll need more time to heal than you would from just missing a few days or workouts. It’s wise to give yourself a day or two of getting back to normal activity and eating before trying to run again.

Of course, it varies by person, but a good rule of thumb is to invest two to three days of recovery for every day you’re sick. So if you’re out for four days, give yourself eight to 12 days to work your way back to regular training. That doesn’t mean sitting on the couch; it simply means investing that time period in short, easy-effort runs for the first few days, building up your time running, and then a few weeks later work intensity and distance back into the picture.

Pushing too hard too soon to try and catch up with your plan can play havoc with an already compromised immune system. It’s best to get back to it gingerly and go by how your body is feeling during and after your runs.

Here’s a sample 12-day comeback plan:

  • Day 1: (A few days post-flu) 20-30 minute easy-effort run.
  • Day 2: Cross-train 30 minutes at an easy effort.
  • Day 3: 30-minute easy-effort run.
  • Day 4: Cross-train 30 minutes at an easy effort.
  • Day 5: 40-minute easy-effort run.
  • Day 6: Cross-train 30 minutes at an easy effort.
  • Day 7: 60-minute easy-effort run.
  • Day 8: Cross-train 40 minutes at an easy effort.
  • Day 9: 45-minute easy-effort run.
  • Day 10: Cross-train 45 minutes at a moderate effort.
  • Day 11: 90-minute easy-effort run.
  • Day 12: Cross-Train 30-40 minutes at a moderate effort.

Again, we’re all different, so this is going to vary by person and illness. The key is to keep your effort level easy for the first two weeks to allow your body time to adapt to the build-back of running time. You may feel weak in the legs for the first week as well, which is another great reason to keep things short and easy for the first few days back. It may feel like you’re starting all over, but you’re not. It will just take time to regain your strength.

Once you gain your leg strength and base back, if you feel strong you can start to weave longer training runs back into your schedule. If you still feel tired and weak, wait to build up your running time, keep your effort level truly easy, and add in some rest days to recover.

Let your body be your guide as you develop your Plan B schedule. First build back to running a solid 90-minute long run, and then focus on tweaking your plan through the rest of the season. That will give you a better gauge as to when you’re ready to go longer.

I develop my training plans so that once you hit the longer kilometres (22+), a shorter long run follows the next week to allow for recovery and focus on race simulation workouts.

If all goes well in your recovery and you get back to training in a few weeks, one option to get in the longer runs would be to drop one of the cutback weeks on my plan and run back-to-back longer runs (ie. 28 kilometres one week, then 32 kilometres, then a cutback week).

Another suggestion is to avoid the race-simulation workouts until later in the season when your fitness is at its highest. Running these while trying to build back your fitness from the flu can really take a toll on your recovery, as the combination of the distance and intensity takes more out of your body.

How you navigate your recovery plays a vital role in how quickly your body can recover and get back into high-quality training. Play it smart now, and you’ll be racing strong this May.

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