Most of us exercise. Some of us have had the guidance of a personal trainer, but few of us have had the opportunity to pick the brain of an expert.

Being a fitness trainer and SOBeFiT magazine’s resident expert, I will share and answer for you here, some common fitness questions. If you have other questions or would like more answers, see below on how you can contact me.

I want to lose weight. Is cardio enough, or do I need to lift weights too?

Cardio does burn fat if you remain in a low-intensity zone, but what matters most is how many calories you burn. We tend to burn more calories in 30 minutes of cardio work, compared to one-third to half as many in 30 minutes of resistance training. However, lifting weights builds muscle—this is key. Muscles are our engines and the big calorie burners in our bodies. The more muscle you have, the more calories you will burn, even at rest. If you increase muscle mass by 3 pounds, you will raise your metabolism by 4%, boosting resting energy expenditure by about 60 calories per day, or about 1,800 calories per month.

This is slightly more than a half-pound weight loss per month.

Okay. So if I want to build body mass, should I skip cardio?

Building mass may be an important objective in a fitness routine, but it should not be the only one. Even serious bodybuilders know that skeletal and cardiac muscles need attention. Focus on lifting moderate to heavy weights, using a high number of sets (eight to 10 reps each) and two to three exercises per body part. Also, incorporate 20–30 minutes of aerobics at low-to-moderate intensity to burn fat and show off muscles you are building. And the heart is one of the most important muscles, so train it with cardiovascular activity.

I want to increase body mass. Is protein enough?

Protein will provide the amino acids necessary to build muscle and support other body functions. But you need other nutrients, like carbohydrates, to build mass. Carbs provide the energy necessary to train hard. If you balance the nutrients in your diet, protein may be converted into carbs to meet the energy demands of your nervous system and muscles. And make sure your sources of carbs are high in fiber, vitamins and minerals.

What’s the best exercise to lose the belly/get great abs?

Sorry, but there’s no way to burn localized fat, or “spot-reduce.” When you exercise your metabolism goes up, which triggers fat deposits to be used as fuel during and after your workout. To decrease fat from any body part, do aerobic exercise for 30–45 minutes at moderate-to-high intensity, circuit-train and have a healthy diet.

I lift weights and have met my initial goals, but I’m no longer improving. What can I do?

You must create new challenges to the muscular, nervous and hormonal systems. Your body becomes more efficient the more it is asked to do something.

For further results, increase the volume of your workout (the number of exercises per muscle group, or the number of sets and reps per exercise) or the intensity of your workout (the amount of weight you lift).

Remember that adding new challenges to your routine may affect your recovery time. Improve your recovery with a good diet and sleep. And evaluate your nutrition. Diet and exercise cannot be separated when it comes to your fitness or sports objectives.

I keep a very healthy diet but I’ve stopped losing weight. What should I do?

In my experience the most common mistakes that prevent continued weight loss are:

  • Drinking your calories. You can have a very healthy diet, but if you drink three lattes a day, it will easily equal an extra meal.

  • Overdoing the condiments, dressings and seasonings. It’s very easy to add 400 calories to your diet in oil—just a spoonful has 120 calories.

  • Excessive portions. Maybe you eat fruits and vegetables, lean protein, good fats and omega-3 fatty acids, whole-grain carbohydrates… a nutritionist’s dream! But look at your plate. How big is that fruit salad or that bowl of cereal?

  • Eating too little. Don’t cut back too much to enact change. Severe calorie restriction is hard to keep up, and it also slows your metabolism. Generally, taking in less than 1,000 calories per day will significantly lower your resting metabolism, making it difficult to continue losing weight. You must eat to maintain your resting metabolism and burn calories. Try to eat five or six small meals throughout the day.

How do I do keep a healthy diet when I have to eat out a lot?

I eat out for lunch almost every day, travel frequently and still meet my diet requirements. Always look for vegetables and lean meat, or what you eat at home. Dismiss temptations and start with a salad or a broth soup, ask for everything plain (dressing on the side), don’t drink your calories with sodas and juices, and instead of dessert have an espresso or tea.

Should I have one diet for me and another diet for the rest of the family?

No. Eating a healthy diet with the appropriate amounts of vegetables, fruits, lean protein and grains should be a long-term family goal. Portion control is the answer.

My husband and I started a diet, but he has lost more weight than me, and in less time! What am I doing wrong?

Men have an advantage when it comes to weight loss. They tend to be more muscular than women, which mean a higher resting metabolism, because the metabolic activity of muscle is considerably higher than that of fat.

But don’t let differences between the genders discourage you. Just be conscious of what you eat and make good food choices.

I have high cholesterol and take statins. Do I need to exercise and watch my diet? Is one more important than the other?

You must follow a good, healthy diet and participate in an exercise program that emphasizes cardiovascular activity. One frequently cited study found subjects taking statins who followed a heart healthy diet (< 30% fat and < 7–10% saturated fat) and an exercise program aimed to burn 1,600 calories per week were able to arrest the progression of coronary artery disease. In the same study, subjects taking statins, following a heart-healthy diet and expending 2,200 calories per week in an exercise program demonstrated a reversal of coronary artery disease.

I practice tennis three times a week. Should I still hit the gym?

According to the recently published federal guidelines for physical activity, yes! An adult should engage in a minimum of 150 minutes a week of moderate-intensity aerobic activity performed almost every day (e.g., 30 minutes a day, five days a week), a minimum of 60 minutes per week of vigorous aerobic exercise (e.g., 20 minutes a day, three days a week), or through a combination of vigorous and moderate intensity exercise. Playing tennis, depending on how skilled you are and whether you play doubles or singles, can qualify as moderate to moderately vigorous exercise. How long and often you play (e.g., three times/week for 60 minutes/session) may allow you to satisfy the aerobic component. However, you also need resistance training two to three times per week to strengthen muscles and bones. A proper resistance program will probably help your tennis game and reduce the likelihood