Nutrition & Physical Activity

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What's a healthy weightlifting schedule?

Dear Reader,

Weight training is an important component of fitness. But just like any other training regimen, rest is an essential factor to muscle health. It is important to leave a day in between exercising a specific body part or muscle in order to reap the benefits of your hard work.

Weightlifting can cause micro-tears in the muscle fiber(s).These tears can temporarily reduce muscle strength and cause some of the soreness you feel after a new exercise or tough workout. Rest time is extremely important, as it allows your muscles to build up the protein necessary to heal and become stronger. All in all, it takes about two days to heal any muscle fibers torn by weightlifting.

If you want to lift weights every day (remember to reserve at least one day a week for rest), try to focus on different muscle groups in three-day cycles, leaving two days in between the same group. For example:

  • Day one: back and biceps
  • Day two: chest and triceps
  • Day three: legs and abs
  • Day four: repeat day one

Other tips to consider for safer weightlifting are as follows:

  • To help prevent injury, start with some light cardiovascular activity to warm up your muscles.
  • Avoid rushing through your weightlifting workout — slow and steady is the way to go.
  • Limit your weightlifting motions while making sure you are keeping correct form. If you are not certain that you are weightlifting properly, you can ask a trainer for some assistance.
  • Remember to breathe! Inhale and exhale normally while you lift.
  • Rest muscle groups adequately between workout sessions (as mentioned above).

Following these tips should leave you in tip top shape — and your muscles happy!


Is it true that eating too many carbohydrates can cause diabetes?

Dear Concerned,

Carbohydrates don't cause diabetes, however eating too many calories overall (from carbohydrates or other types of food) can lead to diabetes in some people. Here's what's going on: Usually when a person eats, her or his blood glucose rises and in response insulin, a hormone secreted by the pancreas, is released. Insulin helps cells in the body to absorb glucose from the blood to use for energy or store as fat. People with diabetes either don't produce enough insulin, or their bodies don't respond to the insulin, or both. As a result, glucose remains in the blood, depriving the body's cells of energy they need, and causing damage to blood vessels, heart, kidneys, eyes, and feet. The Q&A Diabetes mellitus has more detailed information on the disease, as does the American Diabetes Association website.

Diabetes can be brought on by a number of factors, including old age, obesity, lack of exercise, or a genetic predisposition. Eating more calories than you expend, whether they're complex carbohydrates, sugars, fats, or proteins, paired with a lack of exercise and being overweight can increase some people's chances of developing diabetes. This is especially true if there is history of the disease in the family. The good news is that many people with or at-risk for developing diabetes are able to manage their condition through regular exercise and a healthy diet.

Exercising regularly actually helps the body's cells to properly use insulin. Eating a healthy, balanced diet of fresh whole foods (grains, veggies, fruits, nuts, legumes) also helps to ensure the proper functioning of glucose and insulin in the body. For ideas about healthy ways to diet and get in shape check out some of the archived Nutrition and Physical Activity questions.

If you are concerned you may be at risk for developing diabetes, it may be a good idea to make an appointment with your primary health care provider. If you need help learning how to eat right and get in shape, s/he may refer you to a registered dietician.


For more information or to make an appointment, check out these recommended resources:

Medical Services (Morningside)

Student Health Services (CUMC)

Fruits and vegetables that can protect against cancer

Dear Jill,

You're right in thinking that some foods could help improve health or protect against disease. Some of these disease-fighting substances in food are vitamins and minerals, but another diverse group of plant chemicals are called phytochemicals. Phytochemicals, many of which are antioxidants, impart distinct flavors, aromas, and pigments to foods. For example, one enormous class of antioxidants, flavonoids, includes a group called allyl sulfides, which are found in garlic, onions, and shallots. It's believed that allyl sulfides may help produce a detoxification enzyme that protects against carcinogens. Other antioxidants are detectable by their colors — vividly colored fruits and veggies are rich sources of beneficial plant chemicals. For example, anthocyanins are antioxidants that lend the deep red, blue, and purple hues to raspberries, blueberries, eggplant, and red cabbage.

So how do antioxidants work? They are believed to protect cells from "free radicals," which are harmful oxygen molecules. Free radicals may cause damage to cells, possibly resulting in cancer. Smoking, air pollution, infection, and excessive sunlight can all increase production of free radicals, although they are also formed from normal bodily functions. Antioxidants may help prevent the formation of carcinogens (cancer causing substances), block the actions of carcinogens, and/or suppress cancer development. Most of these actions have yet to be proven in humans; however, foods containing antioxidants (mostly plants) contain many other healthy components.

The following table lists various classes of antioxidants and other phytochemicals, some of their rich food sources, and how they are believed to work:


Food Sources

Possible Action(s)

Vitamin C

citrus fruits, tomatoes, peppers, broccoli, leafy vegetables, strawberries, potatoes

Inhibits nitrosamine formation, a potentially dangerous carcinogen


apricots, papaya, sweet potatoes, tomatoes, mangoes, carrots, pumpkin, red peppers, spinach, corn, cantaloupe

Numerous anti-cancer functions


citrus fruits

May detoxify cancer promoters


cooked tomato products, watermelon, pink grapefruit

A class of carotenoids that's protective against prostate and possibly other cancers


blueberries, strawberries, raspberries, blackberries, grapes, cherries, red peppers, eggplant, red cabbage

Antioxidant cell protection; may help prevent binding of carcinogens to DNA

Allyl sulfides

garlic, onions, shallots, leeks, chives, scallions

Various anti-carcinogen functions


parsley, carrots, broccoli, cabbage, cucumbers, squash, eggplant, peppers, mint, basil, citrus fruits

Aid protective enzyme activity


parsley, carrots, citrus fruits, broccoli, cabbage, cucumbers, squash, tomatoes, eggplant, peppers, soybeans, berries

Block receptor sites for hormones that promote cancer


cabbage, Brussels sprouts, kale

Stimulate production of enzymes that break down cancer causing agents

Phenolic acids

parsley, carrots, broccoli, cabbage, tomatoes, eggplant, peppers, citrus fruits, whole grains, berries

Antioxidant properties; inhibit nitrosamine formation and help form protective enzymes


green tea, berries

Antioxidants linked to lower rates of gastrointestinal cancer

As you can see, a wide variety of fruits and veggies fall into one or more of the categories named above. Of note, the benefit from phytochemicals comes from eating the food, not in taking pills or supplements. Fruits and veggies contain a variety of phytochemicals, vitamins, and minerals, as well as fiber — these cannot be replicated in a pill form. In addition, excessive amounts of certain vitamins or other compounds found in some supplements have the potential to cause harm.

To optimize your antioxidant intake, you can include at least five servings of fruits and veggies a day. If you're already doing this, why not aim for even more? Researchers have found that five to nine servings per day are most beneficial. Set your sights on variety, too. To obtain the benefits of these plant compounds, try to vary your selections from day to day, and from week to week. Include red, yellow, green, orange, blue, purple, brown, and white fruits and veggies, and enjoy a colorful (and healthful) eating plan!


Gourmet coffee talk: What's their calorie and fat content?

Dear Wacko,

If you're feeling a little wacko, or verklempt, from all the extras in today's coffee beverages and other specialty hot drinks, you're not the only one. Besides the caffeine, you may feel a lift from the added sugar; some drinks have up to twelve teaspoons worth. Everybody needs a treat or pick-me-up sometimes.  However, if you're concerned about your calorie intake, take note: these drinks often have two to three times the amount of calories and fat of a candy bar. If you add a scone or other pastry... you could be consuming over 1,000 calories in that "little" snack set.

Where are these calories coming from? Many coffee drinks — both hot and cold — typically contain whole milk, sugar, flavoring syrups, and sometimes whipped cream. The drinks you mention above contain anywhere from 250 to 600 calories — for the grande (medium) size. Make it a venti or the largest size available, and the numbers rise even more. To help consumers understand what they're drinking (and eating), the U.S. Food and Drug Administration (FDA) issued a statute that requires all chain restaurants that a) have 20 or more locations, b) offer nearly all the same food items for sale, and c) do business under the same name to list nutrition information on their menus and menu boards. As you can guess, Starbucks falls into these categories. Although other information, such as fat content, sodium, sugars, and total carbohydrates may not be visible on the menus, they are expected (per the statute) to be available in writing at the customer’s request at these establishments.  

If you're concerned about calories, your best bet when frequenting your favorite coffee bar: request skim milk or non-dairy milk (such as soy, coconut, or almond milk), rather than whole. Also, skip the whipped cream or ask for "no whip." The fluffy stuff on top adds at least 100 calories and most of its fat is the saturated kind. Instead of the flavored syrups, try the sugar-free options or try sprinkling cinnamon or vanilla flavoring (which may have some sugar, but you'll add less of it than with the syrup). For people who can't give up the sweet taste, you can add the sugar yourself (each packet contains about 16 calories), or you can use a low-calorie or non-caloric sugar substitute. Of course, if you can't bring yourself to drink the bare-bones coffee, and feel you've got to have the fully-loaded deluxe model, you can go for the smallest size... and skip the pastry. After all, the beverage really doubles as dessert.



Dear Ab man,

Forget pretzel-like positions and expensive gadgets — the best exercise for strengthening your abdominal muscles (fondly known as "abs") is the basic crunch. Proper form is essential to strengthening the abs. Beginners may start with 10 - 15 repetitions. As you become stronger, you may perform more repetitions, or hold each contraction for five seconds, or longer. This can get really tough! Since your stomach muscles are comprised of different sections, you can work each separately.

For the upper portion of the abs, you can do a basic crunch:

  • Lie on your back, with knees bent and feet flat on the floor.
  • Beginners: cross arms over chest; others: rest hands behind the head (be sure NOT to pull on your neck). In either arm position, place your chin at a fist's distance from your chest.
  • Raise your chest and shoulders several inches from the ground, keeping your feet and lower back flat on the floor. Exhale as you come up, inhale as you lower back down.
  • Keep your movements slow and controlled, feeling the contraction in your midsection only. Fast jerky movements do not work the muscle properly.

For the obliques (the muscles on either side of the center of your belly):

  • Start in the basic crunch position.
  • With hands placed lightly behind your head, raise your chest and shoulders, twisting your torso so that one shoulder moves towards the opposite knee.
  • Lower and repeat with the other shoulder, alternating back and forth.

For the lower abs (the section below your navel):

  • Begin in the basic crunch position.
  • Bring your knees up toward your chest in a 90° angle (forming an "L" shape with your body).
  • Using only your abdominal muscles, not your hips or legs, move your knees slightly toward your chest as you exhale.
  • Return to the starting position.
  • Repeat.
  • This is a very small movement — don't bring your knees up to your face.

If you're properly working your abs, but are disappointed with the results, remember that strength training a specific muscle group doesn't reduce the amount of fat over that area. Cardiovascular exercise and proper diet can help reduce body fat. Unfortunately, it is difficult to control where fat loss (or fat storage) occurs. Some people are predisposed to carry a little extra padding in their midsection. Others, because of the way their internal organs are situated, appear to have a bit of a "tummy." Instead of focusing too hard on one area, why not engage in a variety of exercises and strive for overall fitness? You can check out the related questions for some ideas for getting fit. In addition, Columbia students can get active with CU Move.


Health benefits of yoga

Dear Reader,

The word yoga means "to bring together or merge" — as in joining the mind and body into a single harmonious unit. The general purpose is to create physical and spiritual strength and awareness. However, more than one hundred different types, or schools, of yoga exist and each form provides its own unique cocktail of health benefits.

Most yoga sessions are typically comprised of breathing exercises, meditation, and assuming postures (sometimes called poses) that stretch and flex various muscle groups. According to the National Center for Complementary and Alternative Medicine of the National Institutes of Health, relaxation techniques, such as those practiced in yoga, can:

  • Lessen chronic pain, such as lower back pain, arthritis, headaches, and carpal tunnel syndrome
  • Lower blood pressure and heart and breathing rates
  • Reduce insomnia

Students of yoga also generally report:

  • Higher levels of energy and muscle endurance
  • Decreased levels of stress and anxiety
  • Increased feelings of general well-being
  • Increased flexibility, balance, and mental focus

To get the most out of yoga, those with physical limitations (i.e., chronic conditions, pregnancy) may want to consult a health care provider and/or yoga instructor for suggestions on the best yoga styles to pursue. In all, to find the right type of yoga for you, ask yourself a few questions:

  1. Is physical fitness your goal? If you're looking to tone up or shed a few pounds, Power, Ashtanga, or Bikram ("hot yoga") may be a good fit for you. Though not likely to give you much of an aerobic workout or to greatly increase your muscle strength, these forms will get your blood circulating and your body sweating. Those with hypertension or diabetes should consult a health care provider before delving into these forms of yoga.
  2. Do you have any injuries or chronic conditions? Are you and the gym not on good terms right now? Maybe you're new to yoga and want to ease yourself into it before heading straight for the more pretzel-y poses. If this is the case, gentler forms that focus on body alignment and breathing such as Iyengar, Kripalu, or Viniyoga may be the best option.
  3. Perhaps the physical health component of yoga is secondary for you and you're looking more for the spiritual health benefits. In this case, you may want to look into Kundalini yoga, which focuses on chanting, meditation, and philosophic aspects of yogic practice.

There are many more styles of yoga, and depending on what your personal goals are, the health benefits may vary. For more information about different methods of yoga and how to select the one for you, check out the Yoga Alliance website. The whole idea of yoga is to create balance and harmony between the mind and the body, so shop around to see which forms make you feel the best.

Since there are so many different types of yoga, there is no straightforward answer to your question. However, by assessing what you want to get out of your individual yoga practice, you ought to find a style that fits your goals. Namaste!


Does vegetarianism affect teen growth and development?

Dear Concerned,

Just as there are healthy and unhealthy omnivores, there are healthy and unhealthy vegetarians, too. Teenagers are at a critical point in their lives in terms of height and bone development. Including nutritious foods in eating plans is of major importance in terms of reaching their full potential, both for height and bone density.

While adequate protein is essential for bone development and maximum growth, you can get enough protein by eating a varied and balanced vegetarian diet. Including eggs and dairy is an easy way to get protein in your diet, however plants and grains can be combined to give you the protein you need as well (check out Vegetarian wants to bulk up with protein foods for more info). Dairy and eggs contain complete proteins, meaning they have all the amino acids in the right proportions to be used by your body for growth and tissue repair. Dairy foods contain vitamin B12, which is only found in foods of animal origin. This vitamin is vital to your bone marrow, nervous system, and other life-sustaining functions. In addition to calcium, dairy products also contain phosphorous, the second largest component of bone. Look for dairy products fortified with vitamin D, which is needed to absorb calcium.

Whether you include poultry and fish is up to you. For many teens, it is easier to meet one's protein needs by including a wide variety of foods in their diet. Since you need sufficient protein every day, eating poultry or fish on some days can be a healthy option. On meatless days, including legumes, nuts, and/or soy foods can do the trick. Lots of other nutrients, many found in fruits and veggies, are also important for bone health. Can drinking milk prevent osteoporosis? in Go Ask Alice's Nutrition and Physical Activity archive lists some good food sources of bone building nutrients.

Everyone, teens included, must take in enough calories to meet their body's energy needs; otherwise, the protein will be burned for energy, and will not be available for growth and development of strong bones and lean body mass. If a very low-calorie diet is what you have in mind, it would be a good idea to consult with your primary care provider before cutting back on your food intake. It is during adolescence when you reach your fullest potential in terms of bone development (called peak bone mass). If not reached by young adulthood, you can't make up for sub-optimal bone development later in life. So, taking in too few calories and/or protein during the teen years could have implications for your bone health later in life.

This info isn't meant to promote overeating, or under-eating, but rather to help you learn to take in the right amount of food to meet your body's needs. Look first to foods that contain nutrients, and try not to overdo the empty calorie foods, such as soda. Determining what you really need can be challenging, especially because your body is in a state of change.

Your protein and calorie requirements will depend on your stage of growth and physical activity. The Recommended Energy and Protein Allowances, from the RDA, do not take into account these extra amounts you may need. For teens, it's recommended to use height as a measure for calorie and protein needs, rather than weight. To figure out your height in centimeters (cm.), multiply inches by 2.5. Your minimum needs can then be calculated from this chart:


Age (years) Calories per cm. Grams of Protein per cm.
11 - 14 14.0 0.29
15 - 18 13.5 0.26
19 - 24 13.4 0.28
11 - 14 16.0 0.28
15 - 18 17.0 0.33
19 - 24 16.4 0.33


You will need more calories and protein if you are very active and/or are in a rapid growth spurt.

Making healthy choices as you develop during your teen years can help you be healthy for the rest of your life. Kudos to you and your sister for beginning your healthy eating patterns now,


What's the main purpose of electrolytes?

Dear Reader,

Electrolytes are vital to one's health and survival. They are positively and negatively charged particles (ions) that are formed when mineral or other salts dissolve and separate (dissociate) in water. Since electrolytes carry a charge, they can conduct electrical current in water, which itself in its pure form is a poor conductor of electricity. This characteristic of electrolytes is important because the current enables electrolytes to regulate how and where fluids are distributed throughout the body, which includes keeping water from floating freely across cell membranes.

Basically, cells need to be bathed in fluids — inside and out. To control fluid passage across cell membranes, cells regulate the movement of electrolytes into and out of them, which causes water to follow the charged particles around wherever they go. These actions help maintain a state of fluid balance. This is also how electrolytes transport nutrients into cells and wastes out of them. The difference in electrical balance inside and outside of cells also allows for transmission of nerve impulses, contraction or relaxation of muscles, blood pressure control, and proper gland functioning. In addition, the presence of electrolytes determines the acidity or pH of some fluids, especially blood.

As you can see, our bodies have developed mechanisms to keep electrolytes within specific ranges. If one loses large amounts of fluids quickly, however, electrolytes may become unbalanced. This imbalance can occur through vomiting, diarrhea, excessive sweating, serious burns, or wounds. In these cases, water and electrolytes need to be replaced. Life-threatening conditions may result if the losses are severe.

A well balanced diet usually supplies an adequate amount of electrolytes. The major ones are sodium, potassium, and chloride; others include calcium, magnesium, phosphate, and bicarbonate, to name a few. Most Americans get plenty of sodium and chloride from what they eat. Including five or more daily servings of fruits and veggies will provide sufficient potassium. Sports drinks containing these substances are usually only recommended for endurance events lasting over an hour.


Future knee problems from running?

Dear Kneed to know,

Lots of studies have been done on the long-term effects of running on knee health. As a whole, runners seem to have no greater amount of joint destruction or incidence of arthritis than non-runners. In fact, people who are inactive have more mobility problems later in life than their energetic counterparts. Of course, individual variations, such as the way a person trains, one's mileage, rest, recovery, and diet, and the structure of his or her bones and joints, also can have an impact on the health status of knees and other joints.

So, how does this information relate to you? A few concerns come to mind based on the description you give of your training. First of all, it sounds as though you began using the treadmill at a rather high level of exercise. This may cause injury if your joints, muscles, and connective tissue (e.g., ligaments, tendons) are not strong enough to support all of this work. A safe, progressive training program involves increasing duration or intensity by no more than 10 percent per week. (What this means is, if you begin by running 20 minutes the first week, you would increase your time by 2 minutes the second week, and so on.) This gradation computation gives your body a chance to adapt to the growing demands of the activity.

Also, running seven days a week does not allow your muscles the rest and recovery they require for repair and strengthening. Injuries may occur more frequently in people with fatigued muscles. If you feel you must do something every day, try activities that utilize muscles not involved in running, such as upper body weight training. You may wish to use your treadmill a few times a week, and cross-train by swimming or cycling on other days, challenging and strengthening your muscles in different ways. By doing so, you can alleviate the concern of overuse. Varying exercise may also sustain your interest — many people get burned out by doing the same activity day after day after day.

Another consideration is to do some weight training for your leg muscles. It's highly recommended to strengthen the muscles, tendons, and ligaments that support the knee. Knee stretches contains "how-to's" on leg shaping exercises and a description of each muscle or group of muscles that will benefit from such workouts. Many people neglect these exercises because they mistakenly think that their legs are "getting all the exercise they need" from their aerobic activity.


Is decaffeinated coffee safe to drink?

Dear Curious,

In order for coffee to qualify as decaffeinated, it must have at least 97 percent of its caffeine removed. What does that chock up to? An eight-ounce cup of decaf coffee would have no more than 5 or fewer milligrams of caffeine (compared to the range of 40 - 180 mg. typically found in one eight-ounce cup of brewed, dripped, or percolated java). Your concern over the safety of decaffeinated coffee probably stems from solvents used in the past.

Today, most processors use safe methods to remove caffeine. A few different techniques are available, and understanding them may help allay your concerns about coffee contaminants. Coffee beans are decaffeinated by softening the beans with water and using a substance to extract the caffeine. Water alone cannot be used because it strips away too much of the flavor. The goal is to extract the caffeine with minimal loss of flavor. Substances used to remove the caffeine may directly or indirectly come in contact with the beans, and so the processes are referred to as direct or indirect decaffeination.

In one process, coffee beans are soaked in water to soften them and dissolve the caffeine. The water containing the caffeine (and the flavor from the beans) is treated with a solvent, heated to remove the solvent and caffeine, and then returned to the beans. The flavors in the water are reabsorbed by the beans, which are then dried. This process is referred to as "indirect decaffeination," because the beans never touch the solvent themselves. The most widely used solvent today is ethyl acetate, a substance found in many fruits. When your coffee label states that the beans are "naturally decaffeinated," it is referring to this process, specifically using ethyl acetate. Although it doesn't sound like a natural process, it can be labeled as such because the solvent occurs in nature. Other solvents have been used, some of which have been shown to be harmful. One, methylene chloride, has been alleged to cause cancer in humans and therefore is not often used. Back in the 1970s, another solvent, trichloroethylene, was found to be carcinogenic and is no longer used.

Another indirect method soaks the beans in water to soften them and remove the caffeine, and then runs the liquid through activated charcoal or carbon filters to decaffeinate it. The flavor containing fluid is then returned to the beans to be dried. This charcoal or carbon process is often called "Swiss water process" (developed by a Swiss company). If your coffee is labeled naturally decaffeinated or Swiss water processed, you can be assured that no harmful chemicals are used. If you are uncertain, you can ask or call your coffee processor to learn about the method used.

A direct decaffeination process involves the use of carbon dioxide as a solvent. The coffee beans are soaked in compressed CO2, which removes 97 percent of the caffeine. The solvent containing the extracted caffeine evaporates when the beans return to room temperature.

So go ahead and enjoy that Cup of Joe — caffeine free!


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