The Outside Blog

Skiing and Snowboarding : Science

Is CrossFit Killing Us?

IN JULY, nearly 300,000 people tuned in live on ESPN2 to watch 26-year-old Rich Froning and 31-year-old Samantha Briggs win the Reebok CrossFit Games, the last two standing after out-muscling 138,000 global participants in three rounds of competition. For their efforts, which included CrossFit mainstays like burpees and deadlifts, Froning and Briggs walked away with $275,000 each and the title Fittest on Earth—at least according to CrossFit.

Buoyed by the games, CrossFit's high-intensity workouts have exploded in popularity. There are now roughly 10,000 CrossFit-branded affiliate gyms—or boxes, as they're called—around the world. But behind the competitive, puke-inducing workouts is a growing list of injured participants, many of whom suffer from telltale injuries: slipped disks, torn rotator cuffs, knee tendinopathy. Neither the American College of Sports Medicine (ACSM) nor any other association tracks injury rates, but Robert Hayden, a Georgia chiropractor and spokesman for the American Chiropractic Association, says he has noticed a rise in CrossFit patients over the past two years. "Among my colleagues, we often share the anecdotal observation that CrossFit is good for our practices," says Hayden.

Blame the nature of the training. Most Workout of the Day routines (WODs, as CrossFit disciples refer to them) include Olympic lifts like squats and power cleans, which require near perfect form to prevent undue strain. Newbies rarely have the stamina or guidance to maintain that form. Combine that with the high number of reps and it's a recipe for injury.

"If you have a preexisting condition—an old ACL tear, tendon damage, or a slipped disk—this kind of exercise will bring it to the surface," says Hayden.

This isn't the first time CrossFit has been in the injury spotlight. Early on, it earned a reputation for being so intense that it could induce rhabdomyolysis, a potentially fatal condition in which muscle tissue breaks down and is released into the bloodstream. But this time the focus is on musculoskeletal issues. This summer, the Journal of Strength and Conditioning Research published a study showing eye-popping fitness gains among CrossFitters, with participants in a ten-week program boosting their VO2 max by roughly four points. But the study also revealed a troubling statistic: 16 percent of the 54 participants had quit the program due to "overuse or injury." In 2011, the U.S. military, in conjunction with the ACSM, advised soldiers to avoid CrossFit, citing "disproportionate musculo-skeletal injury risk."

In both cases, CrossFit representatives waged a counteroffensive. Reacting to the military findings, CrossFit's chief scientist, Jeff Glassman—father of CrossFit founder Greg Glassman—wrote a 92-page rebuttal that attributed the rise in injuries in part to fatigue from the war on terror.

In CrossFit's defense, the organization goes out of its way to warn people that if they can't maintain proper technique, they should back off. But backing off is a hard sell for many participants, who view the workouts as a competition, especially now that the CrossFit Games are so popular—participation is up more than 400 percent since 2011.

"This year it seemed like everyone at my box was getting ready for the local competition," says 32-year-old former college gymnast Emily Carothers, of Maple Valley, Washington, who finished 23rd at this summer's games. "Many of them were pushing themselves harder than they should have."

Perhaps that's the root cause. Practicing good technique, working around your weaknesses, and staying within your limits doesn't always happen when you're stampeding to beat the next guy. If, however, you approach CrossFit as a sport, complete with cycles of increased workloads and periods of rest and recovery—not to mention an off-season—you can develop a much healthier approach. Carothers already treats it that way.

"I've been doing CrossFit for three and a half years, and I've only had one injury, to my hip," she says. "When I was in college, I had nine surgeries in four years. As far as sports are concerned, CrossFit looks pretty good."

More CrossFit coverage on Outside:

Read More

Is Any Amount of Sugar Safe?

It's official. Sugar is killing us—and our economy. With the average American eating 40 teaspoons of the sweet stuff a day, the related health care costs have reached a startling number: $1 trillion. And it's not just limited to the sedentary among us. High-energy lifestyles may not be enough to burn through all this excess carbohydrate.  

Exercise is Protective
There’s an old saying that if the furnace is hot enough, anything will burn, even Big Macs. And for dedicated athletes, there’s truth to the idea. With enough exercise, you can probably prevent almost all of the negative health consequences of sugar.  There are a limited number of studies on the topic, but fit people appear to be generally protected from junk food diets. Even in people who are otherwise overweight, exercise reduces the quantity of liver and visceral fat stored around organs that is associated with the worst health outcomes. 

In a recent study, investigators in the UK asked a group of fit young males to stop training and be as inactive as possible while they intentionally overfed them  with 50 percent extra calories for seven days. Half of the subjects were then assigned to 45 minutes of vigorous treadmill running per day and got additional food to make up for the calories spent exercising 

The inactive overeaters eaters saw their lipids, glucose, and blood pressure all get measurably worse. But these changes were not seen in the group that exercised. The results related to blood sugar regulation were especially striking:

In summary, our study shows that short-term overfeeding combined with reduced physical activity induced a reduction in insulin sensitivity, hyperinsulinemia and altered expression of several key genes within adipose tissue. The addition of daily vigorous-intensity exercise mostly prevented these changes independent of any net effect on energy imbalance. Whether this is facilitated by regular glycogen turnover or some other consequence of muscle contraction per se remains to be explored. These results demonstrate that exercise has a profound effect on physiological function even in the face of a considerable energy surplus.

Exercise is clearly protective. But the interactions aren’t always as clear in the real world as in the lab. A series of new studies have shown that  at least some people may not respond positively to exercise in the way most of us do. For these non-responders to exercise, too much sugar and too many calories may still pose a legitimate threat to health. 

What About Peak Performance?
Exercise may protect your body from some of sugar’s nastiest effects, but when it comes to peak performance, your bodyweight is a key factor. So while the athlete’s furnace may burn hot enough to avoid the medical problems associated with a bad diet, it’s just not hot enough to let us totally ignore what we eat if we want to go fast. 

That said, most of us live in the real world and don’t have the time, energy, or inclination to eat a pristine farm-to-table diet with minimal processed food and no added sugar. And we don’t need to. Sugar consumption has gone up 25 percent since 1980 as it’s insidiously entered everyday foods. You can cut down to mid-20th century levels out without reinventing your diet:

  1. Avoid routine consumption of sugar-sweetened beverages. And avoid drinking sports drinks on training rides or runs shorter than an hour and a half.  Water works fine.
  2. Replace the high sugar snacks at your workplace with fruit.
  3. Read labels. You will be amazed at how much hidden sugar and high fructose corn sweetener there can be in the snacks you munch on. Your morning muffin from Dunkin’ Donuts may pack 49 grams of sugar. And your afternoon granola bar can easily have upwards of 20 grams of sugar. 
  4. Your swell Frappuccino Blended can pack 52 grams of sugar. Go black or ask to see the nutritional information before you order. 
  5. During the holidays or when on vacation, don’t overthink things. Get regular vigorous exercise and you can afford to overeat. 

Michael J. Joyner, M.D., is a physiologist and anesthesiologist at the Mayo Clinic and a leading voice in the world of exercise physiology. Over the past 25-plus years, he's published hundreds of studies, many of which have focused on how humans respond to exercise. Dr. Joyner also writes at Human Limits. The views expressed in his posts are his own and do not reflect those of his employer.

Read More

What the Heck is the Biological Passport, Anyway?

Recently, and for the first time, the World Anti-Doping Agency (WADA) released a summary of drug testing data for all Olympic-movement sports in 2012. The table- and data-laden report isn't much fun to read, but for people involved in anti-doping campaigns, it was a gift. Prior to this report, comprehensive testing statistics have been publically unavailable—or at least very hard to track down. In some instances, testing agencies themselves didn’t keep data; they had sent it all to WADA, and WADA didn’t always like to share.

The most interesting section of the report covered data about the athlete biological passport, which debuted in 2009 as a next-generation test with the potential to revolutionize anti-doping. And in 2012, according to the report, drug testers collected more than 18,000 samples for biological passport analysis, almost three times the number collected in 2010. At the same time, the report also shows that traditional drug tests are on the decline. Last month, in the wake of American Chris Horner's controversial victory at the Vuelta, the Spanish grand tour, the rider produced six years worth of biological passport data in an effort to clear his name. Some, however, believed the numbers only incriminated Horner further. Whatever the final conclusion, it's good news for the bio passport. If it can prove innocence—or guilt—it may be the most effective anti-doping tool yet developed.

Ok, so what is it?
In simple terms, the biological passport is a series of blood or urine screens taken over an extended period of time (like several years) and analyzed for the effects, rather than the presence, of drug use. In theory, the passport has three components, or modules: one that looks at blood doping, one that looks at steroid use, and one that looks at manipulation of the endocrine system (think Human Growth Hormone). Currently, the World Anti-Doping Agency has only issued guidelines for the blood module, but said last month that the steroid module would go live by year's end. The endocrine module is still in development.

The passport differs from traditional drug testing in two key ways. First, it doesn’t screen for any drugs. Second, it works over time. A single passport screen may not yield much information about doping, but 10 or 20 (or even 30) can reveal not only what drugs an athlete is taking, but when and for what purposes. For drug testers, that’s the holy grail.

How does the blood module work?
A drug tester, working for either a testing agency or a sport’s governing body, pays a visit to an athlete (often unannounced) and draws a small amount of blood. The blood sample is cooled and then rushed to a testing lab for analysis. If samples aren’t analyzed within 36 hours of collection they become useless. (This has made testing in places like East Africa, which is far from all of WADA’s labs, quite a challenge.) 

Passport analysts then look for two things: the percentage in the sample of immature red blood cells, called reticulocytes, and the volume of mature red blood cells. (There is also a third measurement, referred to as an OFF-score, which is a ratio of those two numbers.) In healthy, non-doping humans, none of those values change a great deal. But in doped athletes they do. To understand why, you’ve gotta understand dopers.

All dopers in endurance sports are obsessed with red blood cells. Red blood cells—or more specifically, a protein on the cells called hemoglobin—carry oxygen to muscles. The more RBCs an athlete has, the faster and longer they can race. There are several ways to blood dope, but the two most common involve using synthetic erythropoietin, or EPO, or transfusing blood. EPO and drugs like it work by telling the body to increase its red blood cell production. Blood transfusions are slightly more complicated. When an athlete removes some of his blood, his red blood cell count drops and his body rushes to make more cells in compensation. Like EPO, that makes his reticulocyte percentage jumps. But once those reticulocytes grow up into mature red blood cells, he transfuses his blood back in—say, on a rest day of a grand tour—and suddenly he’s got a bunch more red blood cells than the guy trying to hold his wheel.

For the purposes of passport analysis, an athlete on EPO will have a too-high reticulocyte percentage, as will an athlete who has just removed blood for a transfusion. Later on, the transfusing athlete will have a too-high red blood cell count, and a lower reticulocyte percentage, which has been thrown out of whack by all the extra mature cells floating around.

Hematological scientists have observed that most people have reticulocyte percentages of between .5 and 1.5, and mature red blood cell counts of around 160g/l. Some people are naturally higher or lower, but the trick is watching for variation—dramatic spikes or drops in either number are statistically unusual.

Put another way: All humans react similarly to blood manipulation, and that means taking EPO or transfusing blood messes with people in ways that are both predictable and mostly (but not entirely) specific to doping. So even though EPO often leaves the body before it’s picked up by a drug test, and an athlete’s own blood is essentially undetectable, the passport allows testers find evidence of both.

Is the blood module reliable?
Somewhat. For the passport to trigger a ban, testers like to show a pattern of manipulation. One instance of a high reticulocyte percentage could point to EPO, but also a recent trip to altitude; likewise, a higher-than-normal red blood cell percentage might mean a transfusion or that an athlete is dehydrated. To avoid these problems, athletes are instructed to say whether they’ve recently trained at altitude, and testers are not supposed to collect samples within two hours of a training session or a race. In an email, Dr. Wolfgang Jelkmann, Director of the Institute of Physiology at Germany’s University of Luebeck, who has studied the blood module, called these “methodological weaknesses,” that result in “a relative high risk of false-positive results.”

In response, passport analysts use a complicated formula to account for altitude, the athlete’s genetic background, and other environmental factors when parsing passport data. But given the risk of false positives, the analysis is made deliberately insensitive. The current standard is a 1-in1,000 sensitivity, meaning the passport will only result in a false positive in 1 out of 1,000 analyses (over a series of samples, that means the risk of false positive becomes very, very low) but it will also yield many false negatives. A more sensitive analysis—a standard that would yield 1 false positive in 100 tests—would catch more cheaters. Testers may use this standard when deciding which athletes to target with drug tests, but it is the 1-in-1,000 sensitivity that is used to enforce doping bans. Since 2011, three cyclists have challenged the accuracy of the blood module in front of the Court of Arbitration for sport, and in each case the court upheld the cyclists’ bans.

One final word about false positives: because blood analysis must be performed so soon after collection, athletes don’t get an opportunity to oversee the testing of a B sample as they would for a traditional drug test. WADA, however, does allow passport-sanctioned athletes to examine how their samples were analyzed, and labs must be able to prove that their equipment was functioning properly during each sample analysis. Depending on your perspective, though, the absence of a B-sample like procedure could be a cause for mild concern.

Has the passport succedeed in stopping or slowing blood doping?
Maybe. The bio passport gets a lot of credit for cleaning up cycling, but it’s hard to know how much it deserves. Passport analysis played a key, although not decisive, role in USADA’s case against Lance Armstrong, and this summer if figured prominently in a massive doping case against 31 runners in Turkey. In 2010 and 2011, the Science of Sport’s Ross Tucker argued that an observed decline in overall speed at the Tour de France might mean the passport was working as a deterrent. And, most recently, there was Chris Horner.

But there are skeptics. In 2011, Floyd Landis told reporters that athletes could take micro doses of EPO while transfusing blood and avoid triggering passport violations. A small dose of EPO taken during a transfusion flushes from of the body within hours and boosts reticulocyte percentages just enough to keep the off-score within allowable limits. Other riders have said the passport is ineffective.

Dr. Daniel Eichner, head of Salt Lake City’s Sports Medicine Research and Testing Laboratory, which handled more than 700 passport screens last year, says the current blood module will easily capture “gross manipulators,” people who are either inexperienced or careless when they dope, but doesn’t work as well on sophisticated cheaters, particularly those with access to regular blood screens by their own doctors. 

That said, the passport isn’t only for catching cheaters. “The passport program is a great way to fish where the fish are,” Eichner says. Testers could use the lower 1-in-100 threshold to figure out which athletes should be singled out for more conventional drug tests. “It’s a fantastic way for identifying who needs to be monitored more often," Eichner says, "and over time what you’ll find is that if an athlete gets that kind of scrutiny, because they are cheating, they’ll either get caught or they’ll stop cheating.” Ross Tucker likens the passport to a speed limit: we may never get everyone to drive the legal limit, but if everyone who was driving 100 miles per hour starts going, say, 80 it’s still a major accomplishment.

What’s next?
For starters, until the passport includes steroid and endocrine screens, it has little to say about the integrity of athletes in strength-and-power sports, not to mention endurance athletes who use steroids or HGH. But the steroid and endocrine modules need more research before receiving WADA approval, and research means giving healthy volunteers potentially harmful drugs. “In my mind,” Jelkmann says, “this has to be condemned. It is an ethical dilemma."

And then there’s microdosing. “There is little doubt that it remains relatively easy for savvy athletes—especially those who cooperate with well-skilled medical doctors—to defeat the passport by taking small doses of recombinant EPO,” Jelkmann says. And newer versions of EPO, which came off patent several years ago, can be harder to detect in urine. So it’s certain that some cyclists are taking small doses of EPO and getting away with it. Fortunately, there’s a new, more sensitive test for EPO on the horizon, and with luck testers already have an idea about who those microdosing cyclists are.

But they might not. This summer USADA, which is based in Colorado Springs, was been prevented by the UCI from carrying out tests at the USAPC. And that points to bigger political and logistical fights in the battle against doping. Here are two telling examples: In 2009 and 2010, according to USADA’s reasoned decision against Lance Armstrong, the UCI possessed passport data suggesting that Armstrong was doping, but may have failed to send those samples out for independent analysis. (The UCI disputes this claim.) And last fall, news surfaced that the IAAF wasn’t collecting passport data for many Kenyan and Ethiopian runners because it couldn’t get samples to testing labs within the 36-hour window. That has left a huge gap at the top of the sport.

In an ideal world, all drug testing would be both managed and carried out by an independent outfit like USADA. In reality, it is governing agencies like UCI, IAAF, and FIS—organizations that don’t always like to see positive tests publicized—that are doing the vast majority of passport screens. Cycling accounted for a third of the 18,000-plus passport screens performed in 2012. Skiing analyzed 1,874 samples. USADA performed just 700. Without independent verification, only the most flagrant and reckless cheaters will come to light.

Read More

Free Newsletters

Dispatch This week's featured articles, reviews, and videos. Sent twice weekly.
News From the Field The most important breaking news from around the Web. Sent daily.
Outside GOOur hottest adventure-travel tips and trips. Sent occasionally.
Outside Partners Outside-approved deals and special offers from select partners. Sent occasionally.

to Outside
Save Over

Magazine Cover

iPad Outside+ App Access Now Included!







Previous Posts




Blog Roll

Current Issue Outside Magazine

Subscribe and get a great deal! Two free Buyer's Guides plus a free GoLite Sport Bottle. Monthly delivery of Outside—your ultimate resource for today's active lifestyle. All that and big savings!

Free Newsletters

Dispatch This week's featured articles, reviews, and videos. Sent twice weekly.
News From the Field The most important breaking news from around the Web. Sent daily.
Gear of the Day The latest products, reviews, and editors' picks. Coming soon.
Outside Partners Outside-approved deals and special offers from select partners. Sent occasionally.

Ask a Question

Our gear experts await your outdoor-gear-related questions. Go ahead, ask them anything.

* We might edit your question for length or clarity. If it's not about gear, we'll just ignore it.