fitness and immunity


QUESTION: How hard is too hard? Will cycling compromise my immune system?


Hunter has been inundated with immunity-themed questions over the past few weeks. In these uncertain times, how can we remain fit–while best supporting our immune systems?

By Hunter Allen

Many of you know that your immune system can be compromised after a hard workout and have been rightly concerned about just what constitutes a “hard workout?”  For everyone reading this article, know that you are some of the fittest people on the planet–and are probably fitter than 95% of the rest of the population.  

Increased fitness is a huge benefit of all those long rides, hill repeats, hard races and climbing up mountains–and one of the many reasons you love to ride!   The basic problem is: in these precarious times–how hard is too hard? What even constitutes a “hard workout? A “hard workout” for a newbie is very different than a “hard workout” for a long-time cyclist.  

So how can we properly define a hard workout?

  1. Any ride in which you come home and are “crushed.”  You barely can make it through the door and head straight to the fridge for immediate food or to the blender for a recovery shake.  I remember one time that my best friend and I did one of these epic efforts in college, and I went to his dorm room about 45minutes after the ride–and he was asleep in the bed with his helmet, cycling kit and cycling shoes still on!  
  2. Any ride that you accumulate over 90 minutes of work at your FTP and above.   This is a lot of intensity right now and probably should be avoided as well.
  3. Any ride over 300 TSS.  I would even limit your rides to 275 TSS for now to be safe, but for sure, stay below 300 TSS for your rides.
  4. Any ride that stresses you “thermally” for more than 2.5 hours and/or in which you become dehydrated.  Some of you live in hot environments, and riding in a very hot and/or humid environments for over 2.5 hours is enough thermal stress to be a bit concerned about.   This also goes for dehydration.  Keep yourself hydrated in ALL your rides, much less the ones that are hotter. Keep yourself cool and hydrated.
  5. Any ride in the rain!   Riding in the rain itself isn’t going to make you sick or compromise your immune system. BUT there is a lot of bacteria on the roads and trails that gets flung up into your mouth and nostrils and that can easily make you sick. If it’s raining outside, ride indoors.

I hope this helps to define what constitutes a  “hard ride” or “hard workout.” And just as important–I hope this prevents you from going too deep in the next few months, yet still pushing yourself to maintain fitness and boost immunity.   

It’s perfectly fine to do hard intervals and hard workouts–just follow the suggestions above, and you should keep that immune system strong.

Hunter Allen is a is a USA Cycling Level 1 coach and former professional cyclist. He is the coauthor of “Training and Racing with a Power Meter” and “Cutting-Edge Cycling,” co-developer of TrainingPeaks’ WKO software, and CEO and founder of Peaks Coaching Group. He and his coaches create custom training plans for all levels of athletes.