| While at the Toronto Marathon Race Expo, I was | | | | racing. Another study of marathon finishers involving |
| asked: "Why does running a half or full marathon | | | | 1,694 runners at the 2000 Stockholm Marathon |
| increase susceptibility to colds?" | | | | revealed that almost one in five contracted a cold or |
| There is a large body of research that shows that | | | | other infection within the period three weeks prior to |
| moderate exercise reduces the incidence and | | | | three weeks after the race. |
| severity of a cold or flu but intense or prolonged | | | | Keeping things in perspective, although the risk of |
| exercise increases the risk and severity of infection. | | | | catching a cold after a long hard run or race is |
| The research I found most relevant to runners and | | | | elevated, the vast majority of runners do not fall ill. |
| endurance athletes was conducted by noted exercise | | | | Here are four action steps to enhance your immune |
| immunologist, Dr. David Nieman, Director of the | | | | system and reduce the risk of post-race infection: |
| Human Performance Laboratory at Appalachian State | | | | 1. Take in carbohydrates immediately before, during |
| University. (Lance Armstrong has worked with Dr. | | | | and after racing. Carbohydrates keep your stress |
| Neiman and has been tested in his lab. If he's good | | | | hormone levels and inflammatory markers under |
| enough for Lance, he's good enough for me). Dr. | | | | control, which reduces the risk of infection. |
| Neiman found that running or cross-training 30 to 90 | | | | 2. Get plenty of extra rest. Take an afternoon nap |
| minutes a day several times a week strengthened | | | | and get extra sleep during the following nights. |
| the immune system. However, exercise longer than | | | | Immunity boosting growth hormones are released |
| 90 minutes increased risk of infection. | | | | during sleep. Research shows that the highest levels |
| What happens after 90 minutes of exercise? "When | | | | of killer cells that fight infection are produced after |
| you're running for 90 minutes or longer, there's a | | | | eight hours sleep. |
| temporary downturn in immunity" says Dr. Nieman. | | | | 3. Taking Vitamin C and Echinacea may provide |
| "Around the 90-minute mark, carbohydrate stores | | | | additional support for your immune system. |
| drop, causing a spike in two key hormones, cortisol | | | | 4. Quercetin supplementation is being studied is a |
| and epinephrine. This, in turn, inhibits those neutrophils | | | | means to bolster the immune system. Quercetin is a |
| and lymphocytes (immune cells that fight infection) | | | | phytochemical found in red apple skins and red onions. |
| leaving you vulnerable to nasty bugs." | | | | In an initial study published in the American College of |
| This conclusion mirrors my own experience. In 2007, | | | | Sports Medicine, it was found to reduce the incidence |
| after a training period which had lasted 20 weeks, I | | | | of upper respiratory tract infections in cyclists |
| reviewed my running log and noticed that on five | | | | following intense prolonged exercise. One study does |
| occasions, I had written that I felt like I was coming | | | | not make for a scientific conclusion.......... but stay |
| down with a cold. Every entry was written on a | | | | tuned. |
| Tuesday, following a Sunday long run or race. Hardly | | | | Of course, following generally accepted health |
| a coincidence! | | | | guidelines such as washing your hands frequently and |
| A study by Dr. Nieman of the 2,311 finishers of the | | | | sneezing/coughing into your upper sleeve (instead of |
| Los Angeles Marathon showed that 13% developed | | | | your hand) make especially good sense. |
| an upper respiratory tract infection the week after | | | | |