If you could've chosen any morning for a 2-mile run along the sparsely shaded path beside these railroad tracks, this one wouldn't have been it.
It was only about 9:30, but the sun was already smothering everybody who stepped outside into the thick 90-degree heat.
Herschel Gilbert, celebrating his 20th birthday, wasn't deterred. In a deep blue T-shirt that kept turning darker with sweat, Gilbert led three other young men on a jog north to the gas station, then back down the narrow trail to the parking lot where they had started. When they finished, Gilbert and the others dropped to the blacktop for a quick round of push-ups.
At 5-foot-10 and a muscular 192 pounds -- he has since dropped to 184 -- Gilbert looked every bit the part of the Navy sailor he was training to become. He already peppered his speech with "Yes, sir" and could rattle off the Sailor's Creed as easily as he'd recite the alphabet.
But when Gilbert first walked into the recruiter's office last December here in northwest suburban Crystal Lake, he had taken on the form of his occupation at the time: pizza delivery man. A trim football player during his days at Prairie Ridge High School, Gilbert ballooned to more than 250 pounds after graduation, making him much too large to enlist.
"Everybody knows about the freshman 15," Gilbert said. "I had the freshman 60."
Americans' love of cheesy fries and aversion to exercise are both well documented. But while everyone has heard about the effect of high-calorie living on health care costs and kids' waistlines, scholars and former military leaders say the obesity epidemic also poses real -- but too often overlooked -- problems for national security.
Gilbert, who this week heads to basic training at North Chicago's Naval Station Great Lakes, dropped more than 60 pounds by replacing the pizza with twice-daily workouts to meet the Navy's body-size requirements.
Gilbert's story is exceptional in that he lost so much weight so quickly, but he's hardly alone in showing up to a recruiter's office with dozens of excess pounds. Almost a quarter of applicants to the military are turned away because they're too heavy, statistics show, and about three-quarters of young Americans aren't eligible to serve because of their weight or some other factor.
In 1887, with the Civil War still a relatively recent memory, the military introduced a chart prescribing an acceptable range of weights for various heights. The main goal was to weed out those who were too scrawny or sickly to serve.
Today, recruiters face the opposite problem. Thousands of otherwise qualified young men and women are turned away -- or never bother turning up at all -- because they're too chunky.
"There are a lot more kids that come in just heavier," said Senior Chief Petty Officer Travis Elliott, who oversees six Chicago-area Navy recruiting stations. "It's one of those prevalent things that you see, and we just try to combat it as best as we can."
In Gilbert's case, "combating it" meant an encouraging talk with his recruiter, information about potential workout partners and an invitation to check back weekly and use the recruiting station's scale. To enlist, he needed to either fall within an acceptable weight range or body-fat percentage range. The specific metrics differ slightly between the branches of service.
By the end of February, Gilbert was still heavier than the 191 pounds allowed for future sailors of his height, but he was eligible to enlist because his percentage of body fat had dropped below the maximum level. He has since met the weight threshold, as well.
There's a misconception, military officials say, that any 18-year-old with two legs and a high school diploma can join the service. In fact, recruits must pass a criminal history check, score well on a standardized academic test, not have certain chronic medical issues and meet the body-size requirements.
Most young Americans, studies show, fall short of at least one of those standards. For now, enough people want to join the military that each branch is meeting its recruiting goals. But scholars warn that a rapid troop mobilization -- like those seen throughout U.S. history when the country prepares for war -- could result in too few qualified recruits. That's cause for concern, said retired Air Force Lt. Gen. Norman Seip.
"From a national security standpoint, you can have the best equipment in the world," Seip said, "but if you don't have the people to operate it, you just have a bunch of great static displays."
Seip is part of a group of retired military leaders called Mission: Readiness. The organization, which publishes reports lamenting the number of ineligible young people, argues that government intervention to make school lunches healthier would help broaden the field of potential enlistees and make the country safer.
"By the time a young man or young woman shows up, 17 or 18 years old, if they've been living that unhealthy lifestyle, they're not going to turn it around in a month," Seip said. "We've got to put our resources against that epidemic."
The weight restrictions are about much more than looking good in uniform. Command Sgt. Maj. Louis Barnum, who helps lead Chicago-area Army recruitment, said the rules are an important part of embracing a lifestyle of physical fitness that can save lives in a war zone.
"Having to shoot, move and communicate under fire, or having to carry our fallen off the battlefield, you've got to be in shape," said Barnum, who served two tours in Iraq. "When you're in life-and-death situations, you don't want someone slowing down."
But having too few recruits isn't just an abstract concept: There's recent precedent. Just before the recession, with two Middle East wars raging and a stable private sector, the Army increased enlistment bonuses as it struggled to meet recruitment goals.
"There (were) a lot of casualties in Iraq and Afghanistan, and people weren't particularly eager to sign up. And the economy hadn't tanked, so people had other options," said John Cawley, a Cornell University researcher who co-authored an article in the journal Health Economics about the implications of rising obesity on recruitment.
Enlistment numbers have since stabilized, but Cawley cautions that obesity rates could make speedy mobilizations a plus-sized challenge.
"You can't say it's currently crippling the U.S. military -- that's not true," Cawley said. "But it's a serious problem, and if we get in a situation that we have to rapidly expand the size of the military, then it's going to be a really seriously binding constraint."
Military weight maximums have ticked upward as the American waistline has expanded, but further loosening of standards (and belts) could come at a cost. A 2004 study showed that almost 80 percent of recruits who initially flunked their weight test didn't complete their first term of enlistment. That comes at a significant expense to American taxpayers, who must then pay thousands of dollars to train another recruit.
In 1991, the Army introduced a maximum body-fat percentage for people who couldn't meet the height-to-weight standards. Cawley and his co-author write that the adjustment provided an option for very muscular, in-shape young people to join. Those changes, one of several adjustments to the weight standards over the years, are a testament to how much American bodies have changed since the introduction of body-size standards.
Recruiters are limited in what they can and will do to help prospective service members struggling with their weight. Barnum said recruiters are cautious not to give medical advice or prescribe a diet. If someone wants to shed fat, it's up to them to consult a medical professional and follow a responsible diet and workout plan.
"Our job is to find qualified applicants," said one Navy recruiter, Petty Officer 2nd Class Scott Rose. "It isn't so much to make qualified applicants."
But that doesn't mean they write off everyone with pounds to lose. Rose was Gilbert's recruiter, and he said it was clear from their first conversation that the young pizza courier had the makings of a sailor.
"It was very evident that his interest was very sincere," Rose said. "He had nothing holding him back from joining the Navy except his weight. I hate seeing just one thing be a factor like that. Especially, in regards to fitness, it is something that can be corrected over time, healthily."
That's the strategy Ethan Mueller, 18, employed as he worked to conform his 6-foot, 230-pound frame to Navy standards. In June, he met the body-fat percentage standards. He said he now weighs 200 pounds, a pound below the maximum for his height.
Mueller attributes much of his weight loss to two things: cutting rocky road ice cream out of his diet and performing more manual labor on the Wisconsin dairy farm where he lives. He's scheduled to start basic training in North Chicago in September.
Gilbert, who no longer delivers pizza, can empathize with the challenges of losing weight. After graduating from high school, he earned a basic medic certification from the City Colleges of Chicago with an eye on being a paramedic. But he had also replaced regular workouts with late-night meals of ramen noodles, mac and cheese, and assorted junk.
"I love cheeseburgers just as much as the next guy," he said.
When he decided to enlist, he cut out the fattening meals and began working out. The pounds started dropping at a remarkable clip.
"I knew that I definitely needed to be in shape," Gilbert said. "I knew I was slacking a lot after high school and that really took a toll.
"I was just really motivated to kind of see where this would take me. So far, it's been a great ride."
And that ride is just beginning. On Wednesday, Gilbert starts boot camp.