I’m sitting in the house after 10 days off from running due to a horrible cold. This is rare for me, normally I will train through anything, hating to miss any days. So was I right to take those ten days off? A few key factors led me to take time off: 1) I felt faint after mild exertion; 2) I had a hacking cough; 3) I was feverish; 4) it began as a mild sore throat, which I trained through and got steadily worse over three days. So on the Saturday when I was not sure whether or not to train I e-mailed my coach explained all the above and we agreed rest was best on this occasion.

However, every case is different and every person is different. My partner, who caught what I can only assume is the same virus four or five days after me has continued to train happily and effectively through it. So how do we know if we should train or not?

The ‘below the neck’ theory

Most advice I have read subscribes to the ‘below the neck theory.’ If you have above the neck symptoms – a stuffy nose, mild sore throat and mild headache – you are fine to do some light training and this might help relieve some symptoms by encouraging endorphines and opening up airways.

If however, you have ‘below the neck’ symptoms (cough, tight chest, fever, upset stomach or bowel) then rest might be a safer option.

So what is light training? Well if you use a heartrate monitor or power metre sticking to zones one or two would be a good measure of light training. This would be 1 or 2 out of 5 on the perceived exertion scale.

However, ‘light’ also needs to take into account the time trained; it’s no good thinking that you can make up for your hard interval session by going out in zone two for a couple of hours; this will end up with the same amount of work accumulated and the same compromising effect on the immune system and your recovery.

Training effectively

It’s really easy in the moment to be trapped in a panic about losing valuable training days because you are sick. The reality is that training only really works if it’s of a quality to get you in some way fitter.

If your resting heart rate is raised (over ten beats beyond your normal resting heart rate) you are unlikely to be able to train effectively because even a small amount of effort will have your heart racing whilst providing no real effect on fitness. Of course to know this you need to be regularly taking your resting heart rate.

As John frequently states; ‘you need to start from where you are.’ Two weeks ago you may have been at a certain level of fitness, today you are in different state of fitness so working from where you are today is in the long run going to get you fitter. Forcing yourself out training when you are too ill will only make you sicker for longer, meaning more poor quality sessions or longer enforced rest further down the line.

So how sick is too sick to train effectively? There was an interesting study completed by Kaminsky and Weidner at Ball State University who compared the athletic function of athletes of varying stages of fitness after some were infected with the rhinovirus (common cold). All participants were able to train at moderate and hard intensities with no effect when the cold symptoms were at their worst. Good news? Well it could be if you know that the symptoms you are displaying are the result of the same rhinovirus.

My partner’s approach, given that he did not have access to equipment to tell him what virus he was suffering from was to ‘go out and see what happened.’ What happened was he hit his usual powers and felt generally ok so did his session. My approach may have been similar if the process of getting out of bed had not left me so exhausted I needed a nap!

Key signs to look out for

I’m no medical expert, but I can share with you the signs I look out for when I’m wondering whether or not I should train:

  • I regular measure my heart rate variability using an app (iAthlete and HRV4 are both ones that I have used). This not only gives me an idea of my resting heart rate but of other measures of physiological stress. If this reading is unusual I will take note of other symptoms more carefully.
  • My subjective feeling of fatigue, based on how able I am to get out of bed in the morning and how tired I feel when doing normal day to day tasks (the stairs at work are a good inidicator for me). Fatigue for me is often the first sign that I might be getting ill or could be a sign that I need to lower my training load for a few days.
  • Recent level of training or training stress balance in Training Peaks. A quick look at my training stress balance can often tell me that I might not be sick, just trained hard and in need of a few easy days or a rest day. If you don’t use Training Peaks, you can have a look over your training diary to decide how many long or hard sessions you’ve done over the last 7 days to give you an idea of where the tiredness has come from. If you’re tired and you’ve not been training particularly hard, barring other life stresses, it may be the first sign of infection and time to take things a bit easier to see what happens.
  • Am I feverish? I usually know if I’m running a high temperature due to night sweats and some hallucination. If these things are going on, I know I’m sick and need to take it easy. A simple few minutes to take your temperature can give you some valuable advice about your current state of health.
  • Am I unusually wheezey? I was diagnosed with asthma about 18 months ago, normally steady state training doesn’t activate any symptoms if it starts to and we are not in high pollen season something is wrong.
  • Do I feel unusually cold and unable to get warm? This can be a sign of a fever, but I know that I can also generally just feel cold and unable to get warm when I’m coming down with something.
  • My final question to myself is always, ‘how do I feel about running?’ If the thought of running feels completely beyond my capability, this is usually a good sign I’m too ill to train; I rarely feel like I don’t want to run!
  • The value of an objective opinion is always helpful in these situations; my coach is pretty good at advising me about training when sick and can add that extra third party opinion. If you don’t have a coach, a trusted (athletic) friend can be useful at giving you advice.

Listen to your body.

One of the hardest things I have found to do is listen to my body. Perhaps because the nature of training hard is that we have to constantly override the desire to stop to push ourselves further, so we are used to ignoring our body.

However, being aware of how your body feels and knowing what is normal for you is invaluable. I could have gone out training when I saw my partner going off assuming that given we both had the same virus and he was ok to train so was I. The reality was, the cold hit me harder; I had been away working for three weeks and looking after my sick father so my immune system was already compromised when the cold hit me. Just because two people have the same virus doesn’t mean that they will respond in the same way.

Come back slowly.

So you’ve finally recovered and you’re itching to get back on the training plan. However, depending on how much time you’ve had off and how ill you’ve been will dictate how you come back. I recall having a bad bout of ‘flu’ four years ago and being unable to do anything other than an easy 3 mile loop for four weeks afterwards. At other times after mild symptoms I’ve managed to come back to full training relatively quickly.

Whilst there’s no hard and fast rule, it’s usually a good idea to come back cautiously to avoid any relapse and/or injury if you’ve lost a significant amount of fitness.

If you’ve been really sick it can be sensible to give yourself a ‘wait and see’ day when you feel better to make sure that all symptoms have really gone.

Making your first session back an easy 30 minutes (zone 1) may pay dividends longer term as it helps you really test your body and see how recovered you are.

Once you’ve had a successful easy day you might want to look at extending the time to 45 minutes the next day, then an hour before trying any harder sessions.

If your symptoms return, back off to easier days or rest again.

Avoidance is better than the cure.

Clearly, the ideal is to avoid getting a cold in the first place when you’re training. Whilst not always possible there are a few things that I have practised over the past and have seen well documented in researching this article which might help you avoid the pesky cold altogether:-

Nutrition: good post-work out nutrition not only helps recovery but can help prevent colds by boosting your immune system at a time when it is otherwise compromised. A protein and carbohydrate based snack/drink within 30 minutes of hard training will help do both.

Avoid bonking in training. A poorly managed work out with not enough fuelling not only compromises your training session but can really affect your immune system. Keeping well hydrated and eating as regularly as every 30 minutes for work outs over two hours can not only improve your training quality but help to keep you fit and healthy for the next session.

Hand hygein: colds are passed via spit and snot and traces of these are often on the hands of others suffering from a cold. Washing your hands after such encounters can pay dividends! I have also been known to throw out pens after someone with a cold has ‘borrowed’ it.

Face touching: this is something I struggle with as I often touch my lips and face when thinking. If you are carrying any kind of infection on your hands/fingers then clearly a quick way of becoming sick is to bring that infection into contact with you mouth and nose. I have resorted to sitting on my hands at times to avoid this.

Further questions

Will training help me recover more quickly? Whilst some people report feeling a relief of symptoms after exercise there is no evidence that exercise speeds up recovery. I personally have felt the benefit of exercise at the end of a cold as it seems to help me get rid of final traces of mucus, but this is usually when I have had a few easy days and am feeling better.

How much fitness will I lose by not training? If you are ill you are invariably going to lose fitness. The important question is how to manage your illness so that you recover as quickly as possible and therefore lose as little training as possible. In the end your body will dictate this. I was hoping for a weekend off training; it took me ten days to recover and I’m still not up to full training, but when I am I know that I will be ready for it and benefit from it.

Clare Pearson
Post by Clare Pearson
January 15, 2019
A professional endurance coach since 2018, Clare Pearson has worked with endurance cyclists and runners to help them achieve their goals. Clare specialises in endurance events, she loves to work with people to help them succeed at their own goals; whether that's a personal best, a completion, a podium or better emotional health. Clare will work with you to design a plan that fits in with your day to day life and helps you get the most out of each session.