I've long felt good about my relatively low contribution to global warming; I don't own a car, I take public transportation everywhere, and I walk to the gym. But my self-satisfaction ended when I read a recent Runner's World package on the not-insignificant environmental impact of my favorite hobby. If you have the time for it, this eye-opening feature tracking the manufacture and transport of just one pair of running shoes is well worth a read.

And other sports are not immune; I hate to think of the carbon footprint created by the manufacture of my beloved triathlon bike. (Outside Magazine's November issue has a story looking at whether a ski resort can ever be truly green. The full story isn't online, but the table of contents is here.)

As much as I'd enjoy the view in an NFL locker room, after reading the latest news on Staphylococcus infections in football players, I will pass up any forthcoming invitations. As this ESPN.com story nicely summarizes, the Cleveland Browns's Kellen Winslow is only the latest player to develop an infection from staph, which usually sits harmlessly on our skin but can turn dangerous when it gets into our bodies via a cut or scrape. Other high school, college, and pro athletes in sports including wrestling and baseball have also come down with staph infections in recent years, in some cases MRSA, the potentially deadly strain that is immune to antibiotics. It's not always clear where these and other infections originate, but athletes are at risk because they tend to get nicks and cuts, to have skin-to-skin contact with teammates and opponents, and to share equipment and towels.

That doesn't give you another excuse to hit the snooze button rather than working out, however. Doctors say the benefits of exercise far outweigh the small chance of acquiring staph or another infection at the gym or in the course of your fitness routine. And, they say, you can take some common-sense steps to protect yourself:

As I tossed two pints of Ben & Jerry's Phish Food frozen yogurt into my cart the other day, it occurred to me that with my 401(k) shrinking and the economic outlook worsening, I shouldn't be spending money on sweets. Admittedly, an extra $9 isn't going to make up for my shrinking nest egg, but it just felt imprudent.

I may not be the only one questioning my less nutritious purchases. Conventional wisdom says we turn to comfort foods and cocoon at home in our jammies when the economy goes south. But research suggests that it may actually be the opposite—that during a downturn, we exercise more and are less likely to be obese than when times are good. Christopher Ruhm, the Jefferson-Pilot Professor of Economics at the University of North Carolina-Greensboro, has published research indicating that mortality actually decreases when the economy goes temporarily sour and suggesting that a drop in body weight and increase in physical activity—as well as a decline in smoking—are partially responsible. (He uses the unemployment rate as an indication of the economy's weakness.)

Starting in December, packages of M&M's and Skittles will have a new nutrition stamp that will show in simpler terms the percentage of daily recommended fat, salt, sugar, fat, and saturated fat levels each serving contains. It got me thinking about other potentially helpful changes to food labels, especially after reading in the latest New York Times Magazine that Michael Pollan, author of In Defense of Food, thinks labels ought to include how much fossil fuel energy went into the food's production.

So I contacted nutritionists, dietitians, and nutrition scientists and asked them to brainstorm what they'd like to add, subtract, or change on food nutrition labels. Here are some of their ideas:

• Make serving sizes realistic. These can be misleading if they don't reflect actual habits. Christopher Gardner, a nutrition scientist at the Stanford Prevention Research Center, suggests that if the package were given to 100 people, the serving size should reflect what the average person actually ate. And use ounces and cups rather than grams, adds Heather Bauer, founder of Nu-Train, a nutrition counseling center in New York City and author of The Wall Street Diet.

The U.S. government's overall recommendations for physical activity announced earlier this week aren't terribly earth-shattering: Exercise moderately for 150 minutes a week and strength-train twice a week, and you'll reap substantial health benefits. (I wrote several years ago that the surgeon general and other groups such as the American College of Sports Medicine were already offering that same basic prescription.) But the new report is comprehensive, and in the details there are some tidbits that you might have missed.

1. The government endorses tree-climbing for kids. Kids and teens are encouraged to get an hour of physical activity every day, including bone- and muscle-building exercise at least three times a week. What does that mean? Muscle-building exercises force the muscles to work harder than simply tossing a ball back and forth with a friend. That doesn't mean kids necessarily have to hit the gym (though that's an option); the government says that tug of war, tree-climbing, and the monkey bars all count. Exercises that build bones require impact with the ground; anything involving jumping around should be fine.

I've read all about the bonuses of being a vegetarian. In addition to the obvious benefits for the animals involved, eating less meat is associated with lower rates of cancer, heart disease, obesity, and other diseases and conditions. But not everyone can give up all flesh all the time. For me, it's sushi—can't live without it. My boyfriend, though a longtime fan of Charlotte's Web star Wilbur the pig, still says bacon is his viande noire. As I noted earlier this year, however, being a flexitarian is an option for those of us who would like to move closer to a vegetarian diet without adhering to it absolutely. The question is how to do it, particularly if you're new to a plant-based diet.

Dawn Jackson Blatner, a Chicago-based nutritionist, has written an entire book, The Flexitarian Diet, on the subject. Her goal: to help assuage the fear that eating less meat means being consigned to alternating meals of tofu and raw sprouts with veggie burgers from the freezer section. Instead, she encourages us to think about the sources of plant protein that are already in the cupboard and fridge—black beans, garbanzo beans, lentils, nuts, and eggs, to name a few. Those—as well as, yes, soy products like tofu and tempeh—should take up about a quarter of your plate in a typical meal. Fruits and veggies should be about half, and whole grains should make up the other quarter. None of that is terribly exotic. "Most people have flexitarian tendencies already," says Blatner.

Lance Armstrong, Dara Torres, Brett Favre: They've all been in the news lately for their remarkable athletic comebacks. (And I've written before about how to return to a sport you love, not that those three need my help.) But what if you suspect you need not a comeback but a break—maybe even a permanent one—from your chosen activity?

The notion that you and your running shoes might be well served by some time apart might be a result of chronic injuries or just a general feeling of having been there, done that. Before throwing in the towel, diagnose the problem. If you are constantly battling a string of injuries, it's probably a good idea to try something else for a few weeks or months. Overuse injuries like tennis elbow, runner's knee, swimmer's shoulder, and Little League elbow are so named because they're associated with repetitive motion involved in those sports. Switching to some other activity that uses different muscle groups can give you a chance to recover without losing your aerobic fitness. When you return, you'll probably want to reassess your technique and the intensity with which you've been training. "If you're 45 and playing with college students, maybe it's time to play with 45-year-olds," says William Roberts, past president of the American College of Sports Medicine and a professor of family medicine at the University of Minnesota-Twin Cities.