Task: Explanation
Input (English): Paragraph: Fitness experts say users of the fitness machine, which is a favorite among Army Rangers, Navy Seals, and “The Biggest Loser” television series, reap total body, calorie-busting rewards. “It’s a great and tough cardio piece,” said Neal Pire, an exercise physiologist with the American College of Sports Medicine. “Picture a step mill that combines the lower and upper body, and you have Jacobs Ladder. Except instead of steps, you have rungs.”  Because the user climbs with arms as well as legs more muscles are working and more calories are burned. “As a rule the more muscle mass you utilize during any activity, the greater the oxygen consumed, which is directly correlated to the calories you consumed,” said Pire, president of Inspire Training Systems, in New Jersey. “Unlike stair climbers, you can’t hold on to the sides.”  Jacobs Ladder was invented by Steve Nichols, a fitness champion who injured his knees and back, according to Bob Palka, president of Jacobs Ladder, LLC. “He wanted to come up with a good workout that didn’t impact back and knees.” said Palka, who bought the patent and assets from Nichols in 1994. “Effectively it’s just climbing a ladder,” Palka said. People using the machine are placed at a 40-degree angle to put the spine in a more neutral position, relieve the back of stress and engage core muscles. Palka said on Jacobs Ladder the person’s body weight is lifted over a 12-inch (30.5-centemeter) step for fuller range of motion than the eight-inches of a step mill. “You control the speed,” he said.” The faster you go the faster the runners (on the ladder) come.”  Palka said about 50 to 60 percent of his Jacobs Ladders go to health clubs; some 10 to 15 percent go to the military and physical therapy facilities, respectively. Jacobs Ladder landed a recurring role on the TV show “The Biggest Loser” after trainer Jillian Michaels fell in love with it. “It tends to get your heart rate up,” said Palka, adding that other users, such as the FBI and the Army Rangers, are drawn to the intensity of the workout. John Trail, general manager of a Fitness First health club in Arlington, Virginia, uses Jacobs Ladder in functional circuit and interval training. “You can go for time or you can go for feet,” said Trail. “It’s not a fast-moving piece, but the fact that you’re using every muscle group means you can do 100 feet, rest, jump off, do 10 kettlebell swings, 10 short interval sprints, and burn a lot more calories than you would on an elliptical.”  Trail said a rock climbing buddy likes to climb Jacobs Ladder wearing a back pack for an endurance workout. A self-described competitive person, Trail has even raced with it. “We have two machines side-by-side, so we’ll go for 1,000 feet as fast as possible,” he said. “In under 10 minutes you can get a really good workout.”  He also uses it on clients with joint issues to get their heart rates up quickly. But despite its virtues, Pire said it’s unlikely Jacobs Ladder will supplant the treadmill anytime soon. “The tougher the machine, the more seldom you see it,” he said. “I haven’t seen many seniors hop on. The older population is concerned about balance and falling. And there’s some skill involved in climbing a ladder. But fans are ardent. “Those who use it are almost religious,” he said. Claim: Jacobs Ladder climbers reap tough fitness rewards.
Output (English): Jacobs Ladder, a moving, angled, climbing machine, may be named after the Biblical stairway to heaven, but it packs such a challenging workout people have dubbed it the stairway to hell.