I attended a conference this weekend and had a blast. It is always great fun to see what others in my field are doing. I am a biologist. Biology is a broad field, and while I am an expert in one or two areas of biology, I have a lot to learn in other areas. I suppose that is true of anyone, regardless of their type of training. So below is a list of a few random things I learned (or re-learned), which I thought my readers would find interesting:
1. Levels of both testosterone and insulin-like growth factor (IGF) increase in the blood after cardiovascular exercise. The researchers tested blood before and after a 20-40 min session on a stationary bicycle, at different levels of exertion, and found that both hormones increase during the hour following exercise. The researchers did not follow the participants after 1 hour, so I don't know how long the effect lasts. Levels of IGF increased greater following 40 min of exercise compared to just 20 minutes of exercise, and IGF was also higher after intense exercise (at 90% maximum heart rate) compared to more moderate exercise (75% maximum heart rate). These findings are significant, because both T and IGF function to facilitate muscle growth and repair. I knew this before, but this work reminds me that it is not a direct link between exercise and muscle growth; certain hormones and their cellular receptors must be in place and operate efficiently in order for my efforts to pay off in stronger or larger muscles.
2. Exercise moderates the effects of psychogical stress on a person. We all know that exercise makes us feel good, and this research showed that people who had recently exercised (within a couple hours) were better able to cope with a psychological stressor (graphically disturbing images) than people who had not exercised before exposure to the stressor. The investigators used functional MRI technology to measure brain wave patterns while people viewed disturbing images (violence and injured people). Those who had exercised prior to the fMRI had less brain activity in parts of the brain involved with coping with stress. I am pleased to know about this finding and will plan to use exercise both as an outlet for getting rid of stress, as well as a preventative medicine for combating stressors I might encounter after a workout.
3. An injury to the anterior cruciate ligament (ACL) in the knee may not always need surgical repair. A researcher presented a case study in which physical therapy was utilized for two months following injury with the objective of strengthening the hamstring and quadriceps muscle groups (actually, I can't remember what other muscle group was chosen besides hamstring). With stronger muscles, the knee joint was stabilized and the patient (a college football player) could go back to playing in games. The researcher does note that the knee stability is dependent on these muscles remaining strong. If the patient stops exercising and the leg muscles atrophy a little, the knee will go back to being unstable and may require surgery in the future. I have never had any serious knee issues, but I expect the same principle would apply to other joints. For example, I struggle with a chronic shoulder injury, and I find that weekly rotator cuff exercises keep the joint strong. If I stop the exercises for a string of days, the shoulder feels weaker and I am prone to straining it.
4. Some cases of obesity is due to mindless eating. Dr. Brian Wansink of Cornell University was a keynote speaker at the conference (see http://mindlesseating.org/index.php). He presented his research that showed that the amount of food people consume at meals is dependent on the size of their plate. He also presented work that showed that the good taste of food (which is why +30% of people say they over-eat) is not as much a function of flavor as it is expectation. If you go to a fancy restaurant, you expect the food to taste better, even if in reality it is the same food served at a less-fancy restaurant. Dr. Wansink showed that people ate a greater portion size of "Belgian Black Forest Chocolate Cake" compared to "Chocolate Cake" when the actual cake was the same but the name it was given on a menu differed. He noted with some humor that the Black Forest isn't even located in Belgium...it is in Germany! This research is fascinating and will hopefully help me reduce my caloric intake on strings of days when I don't exercise (otherwise, I can't get enough calories).
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