Why is it that when you are working hard and multitasking like a superhero, you tend to get sick? A recent study by Sheldon Cohen from Carnegie Mellon University examined the relationship between sleep habits and susceptibility to the common cold. The results indicated that there is a direct correlation between how much sleep you get per night and the likelihood that you will be stuck in bed with a rhinovirus after just two weeks of inadequate sleep.

In the study, 153 healthy men and women tracked and reported their sleep volume and quality for 14 consecutive days. At the end of the trial, each participant was quarantined and administered nasal drops containing a rhinovirus. Those participants who had slept less than 7 hours per night were 2.94 times more likely to develop a cold than those who had slept 8 hours or more.

As a fitness professional in New York, I have seen first hand the negative effect that little or low-quality sleep has on my clients. After a couple of weeks of poor rest, my clients invariably develop a nasty cold that puts them out of commission for days, and sets them off track towards good health, success at work, weight loss and fitness, and an active social life. Unfortunately, even if you feel energized after sleeping only a few hours per night, you still make yourself vulnerable to illness. In the study, 77% of the participants reported that they felt rested during the majority of the duration of the study, regardless of their sleep volume. However, the fact remained that if they were sleeping fewer than 8 hours a night, they were significantly more susceptible to developing a cold, despite feeling rested.

If all it takes to avoid a nasty cold taking over your life is tacking on one extra hour of sleep per night, then doesn’t it seem worth it? If committing to more sleep means that you can avoid the doctor’s office, that you can happily relax with family and friends, feel healthy enough to make it to the gym, walk your dog, and keep your life on the track that you’ve worked so hard to achieve, then I’d say getting that extra hour of sleep is worth striving for, no matter how much of a pain it is to fit it into your schedule!

Kristin Haraldsdottir is a personal trainer in New York City. She is currently studying preventive medicine, and studying to enter medical school in 2011. Her future plans are to combine her medical degree, personal training experience, and NCAA rowing experience to inspire others to lead healthy and cardiovascularly fit lives.