Winter Triathlon Training – 5 Ways To Avoid Colds

Is your winter triathlon training being ruined by constant colds? Avoid them now.

Back in 2012/2013 I lived and trained in Stellenbosch, South Africa for six months. The training conditions were perfect, I lived an outdoor lifestyle and for once I wasn’t working in an office surrounded by people with viruses.

Despite being in such a great environment I still kept catching colds all the time, which really hampered my training. After my fourth virus in just eight weeks I knew something wasn’t right, so I decided to take some time out to analyse my training diary to see if there was any link.

And there it was, staring me in the face.

My diary clearly indicated that I kept catching a cold immediately following approximately 14 days of hard training. During that time I was averaging 22 hours per week, which was more than I’d done before and it seemed I wasn’t coping.

It seems obvious looking back, but at the time I was caught up in the day-to-day focus of combining triathlon training and work, rather than looking at the bigger picture. From that point on I decided to reduce my volume and intensity slightly. The result? I didn’t catch another cold for five months.

It also motivated me to research the link between winter triathlon training and colds to see if there was anything else I could do.  This is what I found out – it may help you to realise why you’re susceptible to colds too.


Research shows that intense periods of triathlon training can temporarily weaken your immune system. During hard periods of winter triathlon training, the body produces the hormones cortisol and adrenaline, which raise blood pressure and cholesterol levels and suppress the immune system. This effect has been linked to the increased susceptibility to infection.

The opposite effect has been shown among those who do regular moderate exercise. For example, one study reported half as many colds among those who exercise for 40 minutes each day, compared to a similar group of sedentary people. Therefore, in order to keep improving and stay healthy you need to find the optimal balance between moderate and intense periods of training.

Five Ways To Limit Colds

1. Record and Look Back

If you keep a training diary you should record any periods of illness in addition to your training. Whenever you catch a cold, look back at your diary and see if there was a link. Viruses commonly occur after a fortnight of particularly intense training. A diary can help you identify these patterns and avoid them in the future.

2. Consider Other Forms Of Stress

Life stress, poor nutrition and lack of sleep have all been shown to increase your susceptibility to viruses.

These things are inevitable from time to time, particularly if you have children and a career. It’s important to recognise them and take your foot off the gas during these times. Training hard when you’re already tired and stressed will only make matters worse.

3. Follow The 48-Hour Rule

The most stressful workouts are those that combine bouts of high intensity with long duration. You may recognise these – they are the ones that leave you feeling useless for the remainder of the day.

​Following these workouts your immune system will be suppressed for the next 48-hours. During this time you should either rest completely or undertake light exercise only. If you do more, you’ll dig yourself a hole that could take a week to climb out of.

4. Take Recovery Weeks

Sometimes it’s hard to tell whether you’re fatigued or not, and “listening to your body” is not always enough. When I coach triathletes I set them an easy week every third or fourth week of the month. This active recovery week includes two days off and lighter training on the other days. I have found over the last 20 years that this strategy has coincided with periods of improved consistency and fewer viruses for myself and the athletes I coach.

5. Listen to Your Friends and Family

They may not be athletes, but sometimes the people around you can recognise when you’re over-tired even if you can’t see it yourself. So if your loved one tells you to take a day off training because you look shattered, there’s a good chance they are right.


You can’t avoid all colds, even if you are getting your training and recovery exactly right, but you can reduce your chances of getting so many. If the advice above seems a bit too general, there is another more analytical way to help avoid colds – known as heart rate variability monitoring. There are several smartphone Apps that can help you do that and I covered the subject in more depth in my HRV Triathlon Training blog post.
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Phil Mosley (Coach & Founder)
Phil Mosley (Coach & Founder)

Phil is a recognised expert in the field, having featured on many endurance sports publications. He founded MyProCoach in 2010 to sell premium training plans complete with email coach support for triathlons, duathlons, running & cycling.

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About Phil Mosley

About Phil Mosley

Phil is a successful coach & athlete, having sold over 20,000 training plans on TrainingPeaks and been featured on countless publications. His focus is on smart training that still leaves quality time for your family, friends & career. You can learn more about MyProCoach™ here or preview your training plan now.

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