A call to arms -- and muscular legs

Instead of relaxing at the beach, a few (and proud) vacation masochists sign up for screaming drill sergeants, punishing push-ups and brutal obstacle courses. The goal: to emerge looking and feeling battle-ready. -- Avital Binshtock

Original SEAL PT Course

Houston, (877) 732-5778, www.sealptcourse.com

How hard-core?: The “Total Immersion” program requires 15 hours of outdoor fitness per week, plus three hours of in-your-face training. But there are spa treatments and resort-inspired cuisine for the grunts.

And the results?: Before-and-after photos tell the tale, as do charts of the body-fat measurements of recruits.

Details: An all-inclusive two-week stay is $3,900 to $5,500. Recruits pick their own start dates. Special Forces Camp is shorter (three days), but only the most intense need apply.

*

The Ashram

Calabasas, (818) 222-6900, www.theashram.com

How hard-core?: Boot camp with a yoga-vegetarian twist and 60 miles of hiking. Dance, Pilates and yoga tone down the martialism, as does a daily massage.

And the results?: Lose eight to 15 pounds and possibly gain a famous pal. Renee Zellweger, Oprah Winfrey and Julia Roberts have all done the program.

Details: Drop and gimme -- no, not push-ups -- $4,000. That’s the price for an all-inclusive week here. Still, the wait list is months long (though spaces open up).

*

Mountain Trek

Ainsworth Hot Springs, Canada, (800) 661-5161, www.hiking.com

How hard-core?: Extremely structured one-week program; there’s actually a half-hour spot on each morning’s schedule for “Blister Patrol.” Lots of cardio work on as little as 800 calories.

And the results?: Take home an extra pound of muscle and leave up to seven pounds of fat behind. Nutrition classes aim to keep the weight off long-term.

Details: The 14 guests get massages, private rooms and amenities such as laundry service. But the price might make you stand at attention: $3,360 a week.