9 Best and Worst Times for Surgery, Screening, Sex and More

May 13, 2011— -- Timing is everything, especially when it comes to health. Though there can be no bad time to eat healthy, get a full night's sleep or take your vitamins, much of what's tied to health and well-being can be optimized by doing it at the right time of day, week or year. ABC News has pulled together the best (and in some cases worst) times to undertake nine important health tasks, from screening for cancer to having sex.

Best Time of the Month to Do a Breast Self-Exam

Answer: Two Weeks Before Menstruation

It's long been suggested that women perform breast self exams just after menstruation, when the breast tissue is less swollen and hence lumps are more likely to be felt. The exact opposite is true however, according to Greg Anderson, founder and CEO of Cancer Recovery Foundation International.

"Particularly right after the period, you're going to find more false positives than at any other time. Really, it's the second half of the monthly cycle, before the period, known as the luteal phase, that you want to do a self-exam," he says. Overdiagnosis and overtreatment of breast cancer is a problem just getting recognized by the medical community, Anderson says.

In women 50 years old and younger, dense breasts lead to many false positives, he says. This is in part why the American Cancer Society recommends clinical breast exams only once every three years for women under 40. For women over 50, the chance of false positives is substantially lower, says Anderson.

Best Time of the Year to Check for Skin Cancer

Answer: Your Birthday

While some suspect that winter is the best time to check for skin cancer because the skin tends to be paler (and growths more visible), Dr. Jennifer Stein, associate director at New York University's Pigmented Lesion Clinic, says anytime is the best time to do a skin check.

"We'll often say get your birthday suit checked on your birthday as a way for people to remember. Really, if you see anything new or changing, you shouldn't wait for winter or your birthday or your regularly scheduled appointment. You should get it checked out right away," she says. "The earlier you catch skin cancer, the easier it is to cure and treat."

To know when a trip to the dermatologist is recommended, just remember the ABCDEs, says Stein: asymmetry (if the mole or growth is oddly shaped); border (if there is an irregular border); color (if there are multiple colors in the mole); diameter (if it's bigger than a pencil eraser) and evolving (if the growth is changing).

Best Time of the Day to Get a Colonoscopy

Answer: Bright and Early

Studies have shown that colonoscopies performed in the morning are more likely to catch abnormal growths than those performed in the afternoon. This has more to do with doctor fatigue toward the end of the work day than with the colon itself, according to a recent study in the American Journal of Gastroenterology.

In the study, doctors identified abnormal growths in 26 percent of their morning patients but 21 percent in their afternoon patients. Researchers noted that the difference in detection may also have to do with afternoon patients not taking the full precolonoscopy bowel prep (including large doses of laxatives).

Despite the turnoff of morning breath, having sex right when you wake up may be the best way to start your day.

For men, testosterone levels peak in the morning, resulting in a morning erection and a spike in libido that can leave men not only wanting sex but, some sex experts speculate, with increased stamina.

The hormones aren't all in men's favor: Sex releases feel-good endorphins and boosts production of oxytocin, a bonding hormone that also lifts mood, in both men and women. What's more, according to researchers at Wilkes University, sex boosts levels of IgA, an antibody that helps ward off infection. This means morning sex also means starting the day with a bolstered immune system.

Best Time of Day to Break a Sweat

Answer: Afternoon

Most people think of our circadian rhythms as affecting only our sleep and wakefullness, but researchers have found that other bodily functions run according to their own biolgoical clock. A study presented at Chest 2004, the annual international assembly of the American College of Chest Physicians, showed that lung function had its own natural rhythm throughout the day, dipping to its lowest at midday and peaking around late afternoon, around 4 or 5 p.m. So while we may feel tired and less motivated for that workout after the work day is done, that's when our lungs might be most up to the task.

Best Time of the Week to Stay SoberAnswer: Saturday

It's OK to relax and let loose a bit come Friday, but people tend to be much more likely to drink beyond their limit on the weekends as well. According to a study published in the British Medical Journal, hospital admissions stemming from alcohol abuse were almost 70 percent higher on Saturday -- the result of late-night Friday and early-evening Saturday revelry.

Rule of thumb? One alcoholic drink per hour usually circumvents dangerous blood alcohol levels, but this of course varies according to gender, weight and tolerance.

Not that patients often have a choice in the matter, but Thursdays seem to be the optimal hospital check-in date for patients who want longer hospital recovery time. In a study by the Institute for Public Policy Research, patients who were admitted on Thursday stayed a 24 hours longer in the hospital than those who checked in on Sunday. For those who want to get home as soon as possible, Sunday may be the check-in day of choice.

Best/Worst Time to Schedule Surgery

Answer: Best Is Morning; Worst Is Midafternoon

Going under the knife is usually a stressful affair, but patients can go into the operating room with a little bit of added assurance if their surgeries are scheduled before noon. A Duke University study published in Quality and Safety in Healthcare in 2006 found that those undergoing surgery between 9 a.m. and noon had the lowest incidence of anesthetic-related complications.

Surgery starting between 4 p.m. and 5 p.m. is the worst for anesthetic-related complications, although researchers noted that such complications were very seldom life-threatening. Adverse events were usually prolonged sedation, wound infection, nausea and vomiting. Why would time of day affect this? Researchers speculated that varying degrees of pain tolerance in the patient throughout the day or staff fatigue could be responsible.

Best Time of the Day to Take Heart Medicine

Answer: Bedtime

Regularly taking prescribed medication for heart disease is essential to reducing the risk of a heart attack, but the time of day this medication is taken makes a big difference, according to new research from the University of Guelph in Spain.

Many doctors prefer to give heart drugs to patients in the morning, but this study found that ACE inhibitors, a common drug given to patients following a heart attack, are more effective when they can work overnight while the patient is sleeping. Timing has such a large effect on these drugs that researchers found that ACE inhibitors given in the morning were no more effective than placebos at improving heart structure and function.

This bedtime timing holds true for those who take baby aspirin to thin their blood. In another study from Spain -- the University of Vigo this time -- researchers found that those with prehypertension who took an aspirin at 11 p.m. had lower blood pressure readings after three months than those who took their aspirin at 8 A.M.