En español │As guys get older, one thing doesn't change: That is their ability to enjoy erotic pleasure. But other aspects of lovemaking become considerably different in the 50-plus years: Sex is a form of exercise, and what once felt like football and basketball now seems more like hiking and golf. It becomes less like the Fourth of July, and more like Thanksgiving. But even without fireworks, the erotic flames can still burn hot and bright — if older men adjust gracefully to the changes aging brings. Here are five things you need to know:

See also: 5 myths about sex and aging.

Leisurely embracing your partner can reduce performance anxiety. — Photo by Richard Schultz/Corbis

1. Some things change. Take, for example, erections. After 40 and certainly by 50, they rise more slowly, and become less firm and frequent. Sexual fantasies are no longer enough. Men need fondling, often for quite a while. It's disconcerting to lose firmness and suffer wilting from minor distractions, such as a phone ringing, but these changes are perfectly normal. Unfortunately, many men mistake them for erectile dysfunction (ED) and become distraught — only exacerbating the problem. Anxiety constricts the arteries that carry blood into the penis, making erections even less likely.

In addition, many medical conditions impair erections: obesity, diabetes, heart disease, high cholesterol and high blood pressure.

"Here's my advice to older men with balky erections," says sex therapist Dr. Marty Klein. "Relax, breathe deeply, ask for the kind of touch that excites you — and instead of mourning what you've lost, focus on the pleasure you can still enjoy."

Even true ED need not limit sexual pleasure. "Men don't need erections to have orgasms," says Dr. Ken Haslam, a  retired anesthesiologist who teaches workshops on sex and aging, "I'm 76, and I've had wonderful orgasms without erections, thanks to manual stimulation or oral sex."

2. Some things stay the same. A landmark University of Chicago study shows that about one-third of men age 18 to 49 complain of climaxing too soon at least once a year. And for many older men, premature ejaculation (PE) remains a problem or returns. A subsequent survey shows that PE affects 31 percent of men in their fifties, 30 percent in their early sixties, 28 percent from 65 to 70, and 22 percent from 75 to 85.

PE has two major causes, anxiety and penis-centered sex. Anxiety makes the nervous system — including the nerves that trigger ejaculation — more excitable. And penis-centered sex puts more pressure on the male organ than it can handle.

Young men are often anxious about sex: Will she let me? How do I do this? But older men also have anxieties: Will I raise an erection? Will I stay hard?

In addition, our sexual culture is preoccupied with intercourse, which leads men of all ages to believe that erotic pleasure is located only in the penis: It isn't. Sex therapist Linda Alperstein, advises older PE sufferers to embrace leisurely, playful, whole-body touching, which reduces anxiety and allows arousal to spread all over the body, taking pressure off the penis and reducing risk of PE.

Next: Enjoy sex without intercourse. »