Q: Every year about this time, I head to the gym to burn off some winter fat. Problem is, I always start off overdoing it. Then after I go once or twice, I get a cold. Is it me or the gym or what? — Hugh L., Lafayette
A: It could be the gym, and it could be you. But it's probably a little of both.
The gym is a closed indoor environment, and it's possible to pick up something from the folks who used the free weights and machines before you. (Always clean equipment with an alcohol-based wipe before you use it!)
A recent study published in the Journal of Applied Physiology shows "changes in the distribution of immune cells between blood and peripheral tissues during and after exercise" temporarily weaken your immune system. That, the researchers point out, "leaves our bodies vulnerable to infections, and generally speaking, the more strenuous the exercise, the longer it takes for the immune system to return to normal."
Maybe, Hugh, before your immune system has a chance to build itself back up again after your "overdo it" workout, you pick up an infection at the gym.
The researchers offer an interesting solution: shorten or tone down your workout and beef up your complex carb intake (to mix a metaphor!). They suggest consuming 30 to 60 grams of carbs an hour while exercising. Try a medium banana (27 grams carbs); a mango (50 grams per whole fruit); or three dates (around 55 grams). Post-workout, the researchers say, eating those carbs in the first few hours also aids in restoration of immune function.
We say, if you don't want to opt for activity that's always moderate, try interval training. It gives you brief bouts of more intense effort, but lets you recover more quickly.
Q: I keep hearing that drinking coffee is good for your health. But I drink decaf. Is it coffee or caffeine that's so beneficial? — Katie J., Hanover, N.H.
A: In a nutshell — or a coffee bean — some studies show that caffeine has its own virtues, and others point out that caf and decaf are equally health-beneficial. So, clearly other components in the coffee bean besides caffeine are responsible for some of its healthy rating; after all, it contains over 1,000 biologically active compounds.
Decaffeinated coffee has around 97 percent of caffeine removed — 8 ounces brewed delivers 2-12 mg of the wake-up chemical; a regular cup has about 75-200 mg. So even with decaf you are getting a touch of the brain-boost that caffeine provides.
The benefits of caffeine:
• Stimulates the central nervous system and has neuroprotective properties.
• Helps suppress production of chemicals that contribute to inflammation; increases alertness and improves memory.
• Moderately reduces your risk for Parkinson's disease (by 20 to 40 percent) and its symptoms.
• Significantly reduces your risk of Alzheimer's disease (by 20 to 60 percent) and cognitive dysfunction.
• Reduces exercise-related muscle pain when you drink two or three cups worth of caffeine an hour before a workout. Plus, research indicates that you'll experience more enjoyment from exercise, burn more calories and eat less after you work out.
The benefits of coffee — high-test or decaf:
• Lowers the risk for esophageal, colon and rectal cancers by 20 to 30 percent and reduces the risk for endometrial, aggressive prostate and estrogen-negative breast cancer (and maybe two other cancers), possibly because of polyphenol and anti-inflammatory substances it contains.
• Two substances in unfiltered coffee (although filtered is overall the heart-healthiest), cafestol and kahweol, may improve response to some treatments for hepatitis C, lower elevated liver enzymes and offer some protection against liver cancer.
• Lowers postmenopausal women's risk for Type 2 diabetes by 15 to 25 percent.
• And it may reduce your risk for gallstones and cavities (when you drink it black)!
Dr. Mehmet Oz is host of “The Dr. Oz Show,” and Dr. Mike Roizen is Chief Wellness Officer and Chair of Wellness Institute at Cleveland Clinic. Email your health and wellness questions to email@example.com.