Cat napping the key to solo cruising

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Sleep researcher trains sailors to recharge by taking a series of short naps while under way

Sleep researcher trains sailors to recharge by taking a series of short naps while under way

If you are headed offshore alone, sleep like a dog. Or a cat. Or a human baby, says Dr. Claudio Stampi, whom big-time solo circumnavigators hire to teach them sleep and alertness management. With a wink to Charles Darwin, Stampi says: “We were

Read the other story in this package: Bermuda One-Two a personal endeavor

multiple nappers when we were cats or dogs … including human newborns. More danger means many more times you go to sleep and wake up. A smaller body mass, the more napping you do.”

Switching analogies, Stampi, who says he has taught solo-circumnavigator Ellen MacArthur his tricks, says: “An old-fashioned battery is how we used to sleep earlier in human development,” recharging our bodies repeatedly with short naps over the course of 24 hours. “The modern battery is how we sleep now,” sleeping in one big snooze, having discharged our reserves completely before recharging them.

Stampi in March lectured a score of sailors, about half of them prospective competitors in the biannual Bermuda One-Two race, at the Newport Yacht Club. The doctor urged his students to begin learning what he calls “polyphasic” napping. Roughly translated, this means getting the sleep you need in a series of naps, some clustered together.

“There is a legend that [Leonardo] da Vinci took 15-minute naps every four hours,” Stampi says. A laboratory experiment showed this didn’t work, he says, but that 30-minute naps did. In fact, clusters of shorter naps have been shown to work better than a full night’s sleep, he says. A comparison between competitors in one solo around-the-world race found that the performance of one who slept longer was poorer than that of a skipper who took many short naps, he says.

This doesn’t mean that solo or shorthanded sailors can do well only on short naps. Our sleep comes in four levels, the deepest and most regenerative called “slow wave” sleep, Stampi says. The four levels are experienced over a cycle that lasts roughly 90 minutes, he says. “Deep sleep is reached with or without polyphasic sleep. The brain requires that, so regardless of the way we sleep, whether it’s at night, during the day, polyphasic or monophonic, we will get the deep sleep,” Stampi says.

Experiments show that the total amount of sleep that is necessary, according to the doctor, is between 4.5 and 5.5 hours. On board a boat offshore, where watch keeping is essential, the solo or shorthanded sailor who gets three hours of polyphasic sleep will “make fewer mistakes” than the one who sleeps for three hours in a row, he says.

Stampi began sailing as a child in his native Brazil and combined his love of the sport with his profession. At the University of Bologna, he did research for a dissertation on the impact on the human body of crossing time zones while participating in the 1975-’76 Clipper Race sail around the world. He is founder and director of the Chronobiology Research Institute in Boston.

Stampi says competitive sailors are adept at “knowing very well the race course, the competitors, the boats and everything that has to do with the event that you are going to take part in.” But, he says, “In addition, and this is something people often forget to do … is to do a reality check about yourself.”

The sailor is “the most important piece of equipment that is on board. Get to know what are your strengths and limits and shortcomings. That includes the ability to sleep, to remain awake or alert.” This knowledge, he says, “becomes a tool in the arsenal; an important tool in success, not just a question of safety.”

One measure shorthanded sailors should take is determining whether they are morning or night people, he says. “Morning people are more susceptible to afternoon lows. They prefer a regular lifestyle and experience a fog after dinner,” among other qualities. “Night people have greater sleep recuperation in the morning. They have difficulty benefiting from short naps. They have a slow start to the day.”

The next step is to “pay attention to your own sleep and alertness cycles. Keep a log with a 0-to-10 scale hourly. Determine [by observation] whether you need regularity or are flexible. What are your vulnerable times? What are your own signs of sleep deprivation? What is your recuperation time and strategy?”

Evidence of sleep deprivation, Stampi says, includes poor decision-making, an inability to focus, “cognitive performance errors,” a short attention span, mood swings and irritability, disorientation, a loss of body temperature, altered mental states and apparent bursts of creativity.

Once the self-analysis is completed, it’s time to begin practice naps, the doctor says. He offers some rules:

• Try to wake up spontaneously. Set the alarm as a backup, to go off after you expect to be awake.

• A common mistake is staying awake an excessive amount of time two or three days in a row.

• Bright lights can diminish quality of sleep.

• Multiple meals are good.

• Cardiovascular exercise is good. A hot shower on board is good because it raises body temperature if you can’t exercise.

• Caffeine is not bad if used judiciously. “Whatever you do on land, do half on a sailboat.”

• Sleep comfortably.

Stampi warns sailors to be aware of “sleep inertia” — the tendency of the brain during part of its cycle to remain asleep. “A 50-minute nap has more sleep inertia than a 20-minute nap or an 80-minute nap because [in a 50-minute nap] you wake during the slow wave phase,” Stampi says. “If you woke up after 40 to 50 minutes, you’re likely to find yourself groggy and unable to understand what’s going on,” he says. “You’re better off to sleep 20 minutes or 80 minutes” when “you are on the way back out of slow wave sleep.”

A little sleep inertia is a good thing, according to Stampi. He suggests that the solo sailor “sleep 20 minutes, wake up, check around, go back to sleep.” He says that 70 percent of the times that you awaken, you will have nothing to do but check for traffic. “You’re in a zombie state. If you don’t stay awake too long, you’re still on a downward slope” when you return to your nap, he says.

He gives as an example a study he conducted of Ellen MacArthur’s sleep habits when she was delivering her race boat across the globe. He gathered data from that voyage, he says. The figures that follow are “a result of her natural physiology combined with what she learned during the sleep training program combined with what she could do given the conditions she was facing.”

• Over the course of the 94-day trip, MacArthur averaged 5.7 hours of sleep a day.

• Her longest uninterrupted sleep was 2.7 hours.

• Her longest uninterrupted time awake was 18.5 hours.

• The least amount of sleep she got in 24 hours was 1.8 hours.

• She averaged 9.4 naps per day, 72 percent of them in clusters of three or more.

• Her average nap was 36.6 minutes long.

“Rarely,” Stampi says, “did she awaken at the alarm.”

For these sailors entering the Bermuda One-Two, Stampi predicts that on the first day, “it’s guaranteed you’re not going to feel very well. You should immediately get into the napping process.” Because of the excitement and the stress at the start of the race, he says, “You may need a lot more sleep the first day.”