The growing demand for memory foam mattresses in American bedrooms indicates an interesting, though mildly depressing, trend: People are more apt to spend their hours in bed getting some sleep than getting busy between the sheets.

Memory foam, while cushy, comfortable and conforming, is hardly a firm foundation for doing the horizontal tango.

“It’s like trying to do it in quicksand,” a memory foam mattress owner told Barron’s. And who wants to do it in quicksand?

“There’s a lack of resistance for the knees and feet. And whoever is on the bottom is sinking into the bed,” New York sex therapist Sari Eckler Cooper explained.

But Americans are weighing their options and in these stressful, tired times, they’re choosing sleep over sex.

Memory foam is the fastest-growing mattress trend. Its market share has soared from 14 percent to nearly 20 percent in the past eight years, according to Barron’s. The biggest buyers of these non-sexy mattresses? Baby boomers — perhaps after a certain point in life, you get tired of sex.. or just too tired, in general.