Listed As Probable

German goalkeeper dies in apparent suicide

The apparent suicide of 32 yr old German goalkeeper Robert Enke is a grim reminder of the vulnerability of athletes to depression, as mentioned in a previous post. Missing time recently with the national team due to illness as he was fighting for a spot on the World Cup roster probably did not help his state of mind.  

East Coast vs. West Coast

The Stanford Cardinal football team travels across the country to play here at Wake Forest this weekend. Considering the potential impact of jet lag on performance and what happened to fellow Pac-10 member Cal last year, you would think a west coast team would never agree to a noon kickoff on the east coast. 

 

Not that east coast vs. west coast argument

As outlined nicely in this position statement from the International Federation of Sports Medicine on air travel and sports, there are two theoretical ways that travel across time zones could impair athlete performance.

The first is a mismatch between circadian rhythm and local time. The body's internal clock controls the regular physiologic variations that occur over a 24 hour cycle. Body temperature (and probably other factors like forebrain activation and hormone release) is lowest at 6 AM and peaks at about 9 PM. Athletic performance could mirror these body function peaks and valleys. This theory is partially supported by a 1985 paper which found that athletic performance was best between 12 - 9PM. The position statement authors rightly point out that perhaps, rather than circadian rhythm, we do worse with exercise in the morning because we've recently been in bed for 7-8 hours meaning we haven't eaten much or our muscles are stiff and cold.

The other purported mechanism is what we usually think of when it comes to "jet lag" - a disruption of the sleep-wake cycle. Simply put, you fly from the west to the east coast then don't feel like going to sleep until 2 AM local time because your body is still operating on pacific time, but have to wake up at 7 AM to get ready for the business meeting or game or because the sun lights up your room, and the result is you are tired from only getting 5 hours of sleep.

Either way, the bottom line is that air travel across time zones seems to have an independant effect on team results. A 1993 study in Medicine and Science in Sports and Exercise looked at the win-loss records of NFL teams from 1978 - 1987:

Among all intra-time zone rivals, home teams won 56.6%, away teams won 43.8%, for a home vs away winning percentage change of -12.8% (P < 0.001). West teams (N = 5) displayed fluctuations in home vs away team performance in association with trans-meridian travel. The change in winning percentage was found to be 0.0% vs West teams, -14.1% vs Central teams (N = 8) (P < 0.05), -16.3% vs East (N = 14) (P < 0.05) for West teams (N = 4) flying about 42 h pregame

Now consider college football teams who, due to budget restrictions and the need to minimize missed class time, have to fly in the day before a game. In order to eliminate a potentially unfair competitive advantage for eastern teams, the NCAA should consider a rule that says games involving a team that has travelled across 2 or more time zones have a kickoff time no earlier that 3 PM. At the very least western athletic directors should go by these parameters when working out game times with eastern schools or the television networks. I guess some could argue that trying too hard to even the playing field - as mentioned in this past post about FIFA backing-off its attempt to eliminate high-altitude matches - would reduce some of the variety and intrigue that makes sports interesting.

Another argument against making an actual rule is that the possible negative effects of cross-time zone travel may be limited by some simple planning. The FIMS postion statement describes how circadian rhythms can be advanced or delayed based on light exposure and/or light exercise at certain times of the day. I utilized these techniques when traveling with a US soccer youth national team to Japan, putting the guys through a light workout by a bank of windows in the Tokyo airport at the optimal time while we waited for our connecting flight to Nagoya. Just having a plan seemed to help inspire confidence. The coach, trainer, and I also agreed not to even mention jet lag after that first day in order to avoid any psychological impact. Now we did lose our game to the host country two days after arrival so maybe the strategy didn't work, but on questioning the team at the end of the trip all reported feeling really good the day of that first game and we were the only team in the tournament to even score on Japan so maybe it did have some benefit. Uruguay definitely wished they had planned ahead for the travel stress involved in their home-and- home playoff with Australia for a spot in the 2006 World Cup finals - they had to take a multi-leg commercial flight across the pacific while the Socceroos flew in a custom charter plane with seats removed to make room for beds, massage tables and UV lights. The fresher Aussies go the result they needed in the second leg and advanced.

The body clock can be manipulated even before the trip. One west coast team in the 93 NFL study held practices 3-4 hours earlier in the day than usual to match the upcoming east coast game time which resulted in a winning percentage 2.3% better than expected. Gradually adjusting bedtime and wake time closer to that of your destination can be helpful in the same way. Again, unlike a professional team a college squad may not be able to hold practices at 9 or 10 AM due to class schedules.

Interestingly, both the MSSE study and a paper in the journal Sleep found that NFL teams from the west coast do better than expected against east coast teams when they play at night whether the game is in the west or east! Maybe east coast teams just can't handle the prime-time pressure of Monday Night Football....or when the Seattle Seahawks play a nightgame in New York they can sleep in later on game day and/or they are close to their home time zone late afternoon circadian peak while the hosts are sliding towards the late night performance nadir. So a college team in the east that willingly agrees to schedule a west coast team for a night game - as Ohio State has done both this year and last (a 35-3 loss in Los Angeles) - is a sucker.

Of course, maybe we just all need to suck it up a little bit instead. As the case report of one rugby player in the British Journal of Sports Medicine suggests:

He played in the first two tests before flying to France. From there, he was convinced to come out of retirement for several further matches in Great Britain and France. He flew back to New Zealand, a distance of approximately 20 000 km (and 12 time zones) to be present at the birth of his son by elective caesarean section on 24 November 2005. Although back in New Zealand, he heard that his Kiwi team had qualified for the Tri-Nations final. A few hours after the birth, he boarded a plane to fly back to Great Britain, a further 20 000 km and 12 time zones. He arrived in Manchester just 1 day before the final match. He had flown to New Zealand and back (some 40 000 km) in a span of 6 days. His performance in the final was up to its usual high standard, directing play effectively, plus he kicked a conversion and three penalty goals.

   

   

(Almost) Injury of the Week: Coach tries to kick opponent where it counts

HIV Soccer Scares

Not the good kind of "high five". 6 soccer players from the English Premier League apparently are nervously awaiting HIV test results after finding out that a female soccer groupie recently discovered she had contracted the virus. 

And one of the transvestites, Andre Albertini, who Ronaldo brought back to his apartment last year has died of complications from Acquired Immune Deficiency Syndrome. For his sake I hope Ronaldo really did send them packing once he realized they weren't women. 

Both incidents once again demonstrate that counseling about sexual activity and other risk behaviors needs to be a part of a good sports physical

Bravo to the English Premier League for partnering with Grassroots Soccer in its fight against HIV in Africa. Hopefully the involved EPL players get good news on their test results and celebrate their good fortune by making a contribution to this cause. Click here to make your own donation.

Concussions, Soccer, and Subs

An exciting event occurred recently in the world of sports medicine geeks with the release of the 3rd Consensus Statement on Concussions (think sci-fi fans and the new Star Trek movie). Every four years international experts meet in a middle european city (first Vienna, then Prague, now Zurich) and create a document that ends up setting the tone for concussion management.

In the near future I will try to highlight the differences between the Zurich and Prague statements but one two sentence paragraph within section 2.2 'On-field or sideline evaluation of acute concussion'  caught my attention and is worthy of its own post:

"It was unanimously agreed that sufficient time for assessment and adequate facilities should be provided for the appropriate medical assessment both on and off the field for all injured athletes. In some sports this may require a rule change to allow an off-field medical assessment to occur without affecting the flow of the game or unduly penalizing the injured player's team"

It can be quite dangerous in both the short and long term to allow an athlete suffering from a concussion, especially a young one, to return to play too soon. It isn't the type of injury like an ankle sprain or thigh bruise where you can just have the athlete 'give it a go' and see how he responds. The problem is that concussions are not always obvious, especially if an athlete is motivated to say all the right things to get back in the game. Sports medicine providers on the sideline have to ask a battery of questions, perform a full neurological exam that includes tricky brain teasers and balance testing, and then preferably observe the patient for a short period to make sure we don't notice something suspicious before we can finally rule out a concussion. 

In the paragraph cited above, the committee might as well be saying 'hey, soccer, we're talking to you'. As in other team sports, injured soccer players are moved off the field for evaluation and treatment so that the game can resume. Unlike other sports, soccer has extremely restrictive substitution rules. At the international and professional levels, a team is only allowed three substitutions per match and a player who has been substituted for may not re-enter. The NCAA is a bit more lenient, allowing unlimited substitutions and each player is allowed one re-entry in the first half but none in the second.

So a player goes down after a collision with an opponent and I go out to the field and escort him to the nearest sideline. If I'm lucky I was able to run through a quick symptom checklist between the lines and he denies everything but I'm still suspicious based on the mechanism and how he went down. As I'm running through my tests of brain function ('where are we? repeat to me these 3 objects. List the months of the year in reverse order.) the referee allows play to resume with my team down a man. Our coach across the way doesn't want to burn one of his 3 precious substititions at this point in the contest if he doesn't have to so he waits. I'm feeling pressure to speed up my evaluation but resist and continue in the appropriate manner with a neurological exam (show me your teeth. touch your index finger to your nose). Now I can feel not only the coach's but every fans' eyes burning right through me as our side struggles short-handed. Got to check his balance (stand on one foot. now one foot in front of the other). This process, if I have the courage to see it through, lasts maybe 3-4 minutes which can also be the difference between winning and losing. If the athlete passes all of those tests am I then going to insist on keeping him on the bench another 15 minutes 'just to watch him'? Might as well send him to the showers.

Soccer referees will allow a bit more time for on-field evaluation of a goal keeper before forcing a decision to be made due to the position's specialized nature. This small concession is far outweighed by the fact that there isn't a soccer coach on this earth who trusts his back-up keeper. I had one international game in which we went out to evaluate a keeper who took a knock to the head. I turned to the staff and made the 'get someone warming up signal' with my hands. Eyes over there got wide and a couple coaches put their palms out telling me to stall and not to make any hasty decisions. Finally after 3 minutes the referee asked for the all or nothing decision and I allowed the keeper to continue. Of course, after the game the young man then admitted he actually saw stars initially and still had a headache.

Substitutions in soccer are actually a relatively recent phenomenon, not allowed in the English 1st Division until 1965. This means there is a ton of institutional inertia to fight against when it comes to allowing more substitutions let alone re-entry. One of the primary arguments against more liberalized substitution rules is that coaches would use them as a tactic to disrupt the flow of the game. Another explanation I would buy is that If players aren't forced to pace themselves there would be much less space in which to display technical skill. Players with more energy may theoretically run into each other more often and at higher speeds leading as evidence by this study in which more movements with injury potential occurred earlier in a half. Certainly these arguments don't make much sense when it comes to younger players.

A simple solution would be to allow re-entry for any player suspected of having a head injury. The rather large flaw in this strategy, not that it would ever happen in soccer of course.......

would be that players could simply feign a head injury to gain a long rest and still return. Perhaps a 'reverse substitution' for a possibly head injured player would have to occur within 7 or 8 minutes, allowing for a full evaluation without gaining too much of a rest.

Journal Watch looks at soccer officials and faulty body parts

The March issue of Clinical Journal of Sports Medicine has one of the first studies looking at injuries in soccer referees. I know, many of you are probably saying who cares about refs but we in sports medicine are bound by the Geneva Convention to care for all of God's creatures. The results are summarized below:

A total of 41 injuries during the career were reported by 31 of 71 referees (44%). Injuries were incurred more frequently in training than during matches, and all injuries reported resulted in at least 2 weeks of absence from sport. About a quarter of the referees reported an injury, and almost 90% of the referees reported musculoskeletal complaints caused by refereeing during the preceding 12 months. In male referees, hamstring strains and ankle sprains were the most common injuries, and the hamstrings, knee, Achilles tendon, and calf were the most prevalent locations of musculoskeletal complaints. No significant difference in the incidence of injury or in the frequency of complaints was observed between match and assistant referees.

A lot of weaknesses to this retrospective survey study looking at a small sample of officials from the Swiss professional league but it's a good place to start.

No doubt many a reader is thinking that there should have been an eye exam component to the study.

Well, science has attempted to look at this issue as well and the results may make you just a bit more sympathetic. A 1998 Spanish paper claimed that human eye movement was not fast enough to keep up with the task of making the offside call in soccer. So shouldn't having the linesmen simply listen for the sound of ball being kicked while visually focusing on the relationship between attacker and last defender solve this problem?

A 2000 Dutch study that had linesmen outfitted with eye-monitoring goggles and head-mounted cameras disagreed, concluding that "assistant referees get nearly 10% of offside decisions wrong because they are not standing in the right place". Presumably to try and get clear look at the involved parties "assistant referees tend to stand about a metre nearer the goal than the last defender, and this is why they make these mistakes."

(So kids, make your runs on the linesman-side of the last defender) Some sort of robot on a track on the opposite sideline that mirrored the movement of the linesman would provide a visual reference to ensure that the imaginary offsides line is indeed perpendicular. A less ridiculous measure to provide a frame of reference would be to place a few dots in a grid pattern on the vast unmarked territory between the center line and the penalty areas. Hockey's fixed blue line may explain why NHL linesmen seem to be more accurate than their soccer counterparts despite the faster nature of their game.

A final theory for why assistant referrees have trouble with the offsides call (besides those most commonly heard in the stands i.e. they are being paid off, lack a brain, or just "suck") is the flash-lag effect, which posits that our brains try to make up for the limited ability of the eye to track a fast moving object by 'predicting' it to be ahead of its actual position. This may explain why linesmen usually raise their flags whenever the call is close. Would a simple change in emphasis, such as baseball's axiom that 'the tie goes to the runner', help compensate for this compensation? 

Red Card For Stupidity

Not sure but this may be the first case of threatening a biological attack as a way to trash talk or intimidate an opponent:

"Hector Reynoso has been provisionally banned from appearing in Copa Libertadores games for his Mexican club Chivas Guadalajara, after he spat and expectorated mucus from his nostrils in the direction of an Everton de Chile player during the sides' 1-1 draw, and then told him he had Swine 'Flu."

You stay classy Hector. This is the type of guy who makes bomb jokes in the airport security line. Makes me long for the good old days of the playful throat-slashing gesture .

Upon further review, however, it does not appear that the South American hosts were entirely blameless in the incident:

"Guadalajara players had complained that they were being taunted throughout the game by their Everton counterparts about carrying the disease, and also that they had been publicly mocked by shoppers when they attended a local shopping mall."

Consider yourselves all booked in the game of life. Maybe rather than handing out suspensions the CSF should require everyone involved in the match to volunteer some time in an indigent health clinic or infectious disease ward.

Home Altitude Advantage

The Bolivian national soccer team's recent dismantling of Argentina by a score of 6-1 in La Paz (altitude of Estadio Hernando Siles 3637 meters) has prompted many to revisit the idea of how high altitude settings affect athletes visiting from the lowlands. After all how else could a side languishing near the bottom of the South American standings so thoroughly dominate the #6 team in the world?

Above 330 meters (1000 ft), oxygen content in the air starts to become low enough to potentially impair human performance. The unacclimated body responds to this stress in 3 primary ways: 1) increasing respiratory rate to grab as much oxygen from the air as possible 2) increasing hemoglobin levels in order to improve oxygen carrying capacity of the blood 3) increasing heart rate to move those oxygen carriers around to gasping tissues as fast as possible. This process at 2100 meters takes at least 2 weeks to get up to speed. In the meantime a spectrum of misery can occur from headaches, stomach upset, sleeplessness, and of course fatigue to potentially deadly brain swelling and fluid in the lungs at the higher elevations reached by mountain climbers. Unable to devote a fortnight to acclimatization Argentina adopted the common strategy of arriving inLa Paz only a few hours before match time in order to play the game before the unpleasant symptoms of mild altitude sickness kicked in.

It was only a couple of years ago that soccer’s international governing body FIFA outlawed games above 2500 meters saying that such low oxygen conditions were dangerous to athletes only to back track a year later when unable to provide any substantial proof of this claim and not to mention the public outcry led by the influential and certainly unbiased voice of the now head coach of the Argentine national team Diego Maradona. Maradona even played in a 60 minute game in La Paz to prove that if a 47 year old can do it so could fit young pros (his ability to coach at this height is in serious doubt however). The slope could also get quite slippery in a hurry as cases could be made that both heat and air pollution do pose actual health risks to athletes. It wouldn’t be long then until Mexico reasonably claimed that it is not in the spirit of fair play for them to have to face the US in the cold of a February night in Columbus, Ohio. Attempts to standardize playing environments would also remove a great deal of the rich texture that makes soccer so intriguing especially at the international level. Imagine baseball without the ivy covered outfield walls of Wrigley Field or the NFL without Green Bay’s frozen tundra.

So why doesn’t everyone train in the clouds every chance they get? High altitude exposure does result in beneficial adaptations such as increased hemoglobin but the overall performance gains you would expect to reap from this at sea level are negated by the fact that you can’t push your training as hard as you can at lower elevations; muscles can’t push themselves to the edge when they don’t have enough oxygen and aren’t forced to fight as much air resistance. Exposure over generations probably explains overall shorter stature and less muscle mass of natives. Bolivians and Ecuadorans can’t just move to Holland and expect to dominate the Dutch Leagues based on physiology alone. Bolivia has only been able to salvage 1 point in their away matches so far in this qualifying campaign. So living high but driving down the mountain and training low may combine the best of both worlds when attempting to improve performance at low altitudes. It isn’t quite clear if 7-8 hours of sleeping in a low oxygen tent is enough to capture this effect without the commute.

Another interesting question to consider is do countries like Bolivia and Ecuador (Quito's elevation is 2850 meters) maintain their home altitude advantage if their players are plying their trade with clubs near sea level and then return home only a few days before a national team match? It turns out that native highlanders don’t rely on the same adaptations that native lowlanders do to survive at altitude. Rather than transiently increasing hemoglobin, ventilatory rate, and heart rate natives most likely rely on more permanent improvements in how oxygen is transferred from the lungs to working muscles such as increased number of capillaries in the lungs, hemoglobin that grab on to oxygen more tightly, easier dilation of blood vessels, and more efficient mitochondria powering the muscles. These inherent factors allow natives to adjust to higher elevations much more quickly than non-natives. The blueprint may have been shaped over generations and hardwired in to the genetic code. One study demonstrated that second generation Tibetans who had lived their entire lives at sea-level were still able to adapt to altitude much more quickly than both trained and untrained Caucasians. Of note, 4 of Bolivia’s 11 starters and 1 of their 3 subs in the Argentina match play for clubs based at normal elevations. Perhaps those more familiar with the team can report if that is typical for home matches and if a higher percentage of foreign based players are used for away contests in Buenos Aires, Rio, or Montevideo.

Of course performing well at altitude is not impossible (Argentina was able to earn a 2-1 victory in La Paz four years ago in fact) but it is literally an uphill battle. And if a Sherpa starts talking trash to you as you huff and puff on your next climb of Everest challenge him to a nice long race on the beach in a few months.