Sure you want to eat that? You just did a run... visual appeal of food changes with exercise

For the past two weeks I started playing in an intramural league for soccer. It's a team made up of fellow grad friends and  has been more fun than I initially gave it credit for. It's a great form of release after a long day at work, and there's this great collegiality among your teammates in sharing the joys of a scored goal (we got 1 point last game, making our final score 1-5, 1 more point than we usually score!) or ragging on bad sportsmanship in a competing team.

Partly why our team is so awesome and we don't get totally slaughtered - we have an awesome goalie!

Another thing I didn't expect about playing outdoor soccer - the amount of soreness that I woke up to. I try to run regularly, but my body wasn't ready for the soccer match. Soccer, in my opinion is considered a high intensity exercise. There's bouts of sprinting down a field to catch a soccer ball, dodging to avoid getting hit in the shins by a stampede of competitive feet, and lots of quick movements to try to intercept balls. The day after our game, I couldn't move my thighs and had a 6 inch bruise and scratch running along my quad muscle, courtesy to the CogSci grad girl who decided to knee me during a play. You know how sore you are when in order to move your legs, you use your arms to pull up your legs... getting older, I tell you.

Despite the soreness, there's this great adrenaline and natural buzz that you feel after doing something physical. It's no secret that exercise is good for you. Exercise promotes brain growth and development (Cotman and Berchtold, 2002). High intensity exercises also enhance metabolism, burning off more fat than alternative exercises (Irving et al., 2008). But how about the effects on food? In particular, does our perception of food or how good something looks, change after exercise? Would our favorite indulgences lose appeal after doing some circuit sprints on the court?

Your call: a chocolate-y delight, or too close in resemblance to something else...?

As it turns out, a recent article published in the American Journal of Clinical Nutrition investigated how subjects perceive food following high intensity exercises.* One of their findings showed that areas of the brain responsible for "craving" foods were activated more when seeing low-calorie foods than high-calorie foods. This means that after a hard spin session, kickboxing class, or cross-fit boot camp, there's some sort of cross-talk between your muscles with your brain, signaling a preference for you to reach for the apple other than the curly-string fries. One caveat to this study, however, is the subjects were all male, so it would be interesting if there are any sex differences to this finding (maybe evolution would favor women to always crave the higher calorie food to promote survival and childbearing - it could explain why after a long run, I like to reach for a bag of cheetos).

Last weekend was Vietnamese/Chinese New Years. Vietnamese New Year is all about good fortune and prosperity. It's customary to normally ring in the new lunar year by doing a food offering for your ancestors, often cooking many traditional meals (somewhat analogous to Day of the Dead). During this offering, you ask for forgiveness for the past year, ask for luck for an upcoming mysterious new year, and ask for hope for your loved ones to succeed. New Years really focuses on spending time with friends and family and giving well wishes to loved ones.

A traditional setting for New Years - a feast offering for ancestors. Photo courtesy of D. Dinh

This New Years (albeit my greeting comes a bit late), I'd like to wish everyone a happy new year filled with lots of luck and good eating. I'm sure many of us have made resolutions to study or work hard, try to be healthier, procrastinate less, etc., but maybe this year, we can squeeze in moments full of good food and good company.

Good company not always appreciated, apparently by bunny

*The mentioned study was conducted using 15 physically-fit men who did 60 minutes of running at 60% maximum aerobic capacity and a resting control. After each trial, imaging of the brain was done using functional magnetic resonance imaging (fMRI) to see which areas of the brain were differentially activated. They found that neural areas known as the reward system (insula and putamen) had increased activation to low calorie compared to high calorie food following exercise. In accordance to other studies, researchers also found appetite suppression (lower grehlin concentrations) after exercise.

References:

Cotman CW and Berchtold NC. 2002. Exercise: a behavioral intervention to enhance brain health and plasticity. Trends in Neuroscience. Jun; 25(6): 295-301.

Irving BA et al., 2008. Effect of exercise training intensity on abdominal visceral fat and body composition. 2008. Medicine and Science in Sports and Exercise. Nov; 40(11): 1863-72.

Crabtree DR et al., 2014. The effects of high-intensity exercise on neural responses to images of food. American Journal of Clinical Nutrition. Feb;99(2): 258-67.