From Muscle & Fitness Magazine

17 common training and nutrition questions
What happens when ... You have sex before working out? And other common training and nutrition questions

In the world of health and fitness, old wives' tales and gym lore are oft repeated, chapter and verse, as hardcore fact. Opinions are bandied about as truth, and legend is taken as history. Health clubs are home to more speculation than the pork bellies market. And that's just the way it's always been. Until now.

We've recruited bona fide experts in the fields of exercise science and nutrition to help us answer 17 questions that have historically been ripe for speculation, guesswork and hearsay. So now, instead of listening to the advice of your training partner's friend's roommate's sister, you can be the one giving it. But one word of caution: You may find your standing among old wives seriously downgraded. So, what really happens when . . .

1) You don't wear a belt during heavy lifting? According to nutrition and exercise guru Chris Aceto, there are two sides to this coin. "If you don't use a belt when lifting heavy, you could possibly injure yourself because belts support the abdominal and lower back muscles -- the stabilizers of the trunk region," he says. "Paradoxically, when people start out training with a belt, they don't build those stabilizer muscles, so the risk of injury increases as the strength of other muscles increases." In other words, use a belt only to help prevent possible injury on your heavier sets, not to take the place of supporting muscles.

2) You eat too much or too little protein?
We all know that protein builds and maintains muscle (at least all m&f readers do it). So we do our best to get the right amount of protein to reach our personal fitness goals. But what happens on those days your meal schedule gets derailed?

Aceto explains: "If you eat too much protein, the excess is sent to the liver, changed to a sugar and used as fuel, stored as glycogen or stored as bodyfat. Many people don't realize that protein can be stored as fat. Conversely, if you eat too little protein, you fall into a negative nitrogen balance, meaning there aren't enough amino acids to make your muscles grow." All the more reason to keep a log of your daily nutrient intake. Try to stick to 1-1.5 grams of protein per pound of bodyweight daily.

3) You get less than eight hours of sleep?
Sleep deprivation has reached epidemic levels in the United States. While eight hours of work, eight hours of play and eight hours of sleep used to represent the magic triangle of balance in a person's day, our current version is an isosceles, with the sleep side getting ever shorter. What does this mean to you, the dedicated trainer?

"Sleep need is an individual thing," notes m&f Science Editor Jim Stoppani, PhD. "But research supports the fact that most people require between seven and nine hours. You should strive for at least seven; otherwise you risk perturbations in your hormone levels, like growth hormone, which seven hours tend to gain more bodyfat."

4) You don't stretch on a regular basis?
Between work, the fiancée, Sunday afternoon with the kids and your Internet addiction, you've got maybe an hour a day, four days a week, to hit the gym -- and you're not about to waste one minute of it stretching. So what's the worst that could happen?

"You'll lose flexibility and range of motion in each muscle," reports Aceto. "Consequently, you won't be able to overload the muscle through its entire range, and you'll limit your growth potential." Stretching is best done after working out to maximize flexibility and range of motion. It's never a good idea to stretch cold muscles, because it could lead to muscle pulls and tears.

5) You eat a meal (or meals) after 9:00 p.m.?
"Diet experts" often advise not to eat after 9:00 p.m. But what if you do?

"If your goal is to build muscle, you should consume a slow-digesting protein like meat or a casein product within an hour before sleeping to provide amino acids throughout the night," Stoppani advises. "Without them, muscle breakdown occurs while you sleep. As far as carbs go, some controversy exists. Many bodybuilders get good results by not eating carbs within four hours of bedtime. Others say it doesn't matter, as carbs won't make you fat if you don't take in excessive calories throughout the day."

A good rule of thumb: Try to grab a protein-rich (30 grams or so), low- to moderate-complex-carbohydrate meal about an hour before bedtime. Your muscles will thank you in the morning.

6) You try to train while you're sick?
"Studies show that exercise will generally cause an acute suppression of the immune system," states William J. Kraemer, PhD, CSCS, director of research and a professor in the department of kinesiology at The University of Connecticut, Storrs. "But with things like upper respiratory tract infections [colds], it's not going to do much damage and can even be beneficial if the exercise isn't too intense."

But what about the feverish? "If you're experiencing any flulike symptoms, you don't want to take the chance of compromising yourself and making things worse," Kraemer warns. Plus, it's not polite to sneeze on your gym partner while he's benching.

7) You train a bodypart two days in a row?
This idea is all but taboo in gym circles; the common belief is that it will surely lead to overtraining.

"We've trained people on consecutive days and have had success with it," Kraemer points out. "But the key is, the rest period following needs to compensate for the intensity of the workouts. This means between workouts, don't do any other type of activity -- just go home, eat and relax. It's also important that you vary the load on the muscles and the angle of the exercises. For example, if you were to train chest on consecutive days, you'd want to do flat benches on day one and inclines on the following day, or vice versa."

While this shouldn't be the basis of a long-term approach to your training, you could certainly incorporate it as a short-term way to shock your muscles into new growth. And make sure you consume sufficient carbs, protein and total calories.
 

8) You have sex before working out?
"Women weaken legs!" This infamous caveat bleated by crusty boxing trainer Mickey Goldmill to Rocky Balboa as he trained for his title shot made many a lonely lady out of athletes' wives and girlfriends. Did Mickey know what he was talking about, or did he have a few marbles knocked loose during his fighting days?

"It depends on who it's with," jokes Aceto. On a more serious note, he a