Monday, August 29, 2016

What is the absolute limit for human athletes? Here’s the science …

Course leader MSc Sport & Exercise Nutrition, Lecturer in Exercise & Environmental Physiology and Exercise Immunology, University of Westminster
From The Conversation
The Olympics have drawn to a close and this year saw the shattering of 19 different world records, some by staggering margins. US swimmer Kate Ledecky broke the 800 metre freestyle record, which she herself had previously set, by almost two seconds – a mammoth margin compared to the tenths and hundredths of seconds which often decide Olympic success. As we continue to swim faster, jump higher and throw further than ever before, these performances have left us wondering just how much further athletic performance can be pushed.

Many have tried to establish what the absolute limits for human performance are and science can provide us with some clues as to what they could be and when we will likely reach them.

It is clear, that there has been a dramatic improvement in athletic ability over the past century. This is reflected by the continuous improvement of world records in track and field athletics from the early 1900s, which tend to follow a linear rather than an exponential trend. However, this progress is not distributed evenly across the various disciplines of track and field athletics.

Over the last 100 years, large improvements have been made in the javelin and shot put, for example, while much smaller gains have been made in short-distance races, such as the 100, 200 and 400 metres. In 1909, for example, the men’s shot put record was 15.54 metres; the current record, set in 1990, is 23.12 metres. This means that we had an increase of almost 50% in throwing distance in just over 80 years. By contrast, the improvement we have seen in the men’s 100 metres over the last century is a relatively small 8%.

The rate of improvement for women, however, has been extraordinary, and overall greater than that observed for men over an identical period of time. Looking at the 100 metres, for example, women improved their performance by a huge 30% in just 80 years. As we have seen previously, men had just an 8% improvement in more than 100 years. This difference is even bigger in many other disciplines.

It has also previously been demonstrated that the sequence of records in the history of athletics is not distributed in a random fashion, but that a distinct regularity exists.
Why are we getting better?

Could such regular improvements over time be due to cyclical training techniques, whereby a novel training technique is applied to a generation of athletes until something more effective is found and then applied to the next generation? Or could it be down to the more effective discovery of elite athletes in consecutive human generations? The honest answer is that evidence is currently lacking as to which potential mechanisms might be dominant.

Some factors do seem to play a part, however. First, economic advances and broader coverage of sports by the media have contributed to a growth in the base number of athletes, including those competing at higher levels. Statistically speaking, this increases the chance that “extreme outliers” (or peak performers) will occur in a normal distribution of athletes, and may partly account for the improvement in records.

Second, genetics might be involved. Several genes influence athletic performance, which can thus be considered a polygenic trait – one in which a large number of genes, each one having a relatively small effect, contributes to an outcome. A high degree of natural selection will have occurred over time, and the best athletes might be increasingly characterised by a prevalence of these genes.Women are beating world records more quickly than their male counterparts. Gerry Penny//EPA

This may also account for the lower improvement of athletic performance in sprints (for example, 100, 200 and 400 metres) when compared with middle and long-distance events (1,500 and 10,000 metres and the marathon).

The performance of sprint athletes mostly depends on two variables: reaction time and fast muscle fibres. In endurance athletes, meanwhile, peak performance is regulated by slow muscle fibres, and by aerobic capacity. The latter can substantially be increased by either regular training or manipulation (blood doping, for example). Conversely, reaction time, which is strongly dependent on the nervous system, has a limited margin of improvement when compared with muscular power and aerobic capacity. Indeed, the nervous system cannot increase the speed of transmission of an eletric impulse, therefore there is little potential to improve reaction time through training. Here, genetics is key.

Equally, jumping events are limited by tendon stress limits, which cannot be overcome past a certain natural limit and this might explain why the curve of improvement for these specialities is now almost flat.

Whether and by how much genetic selection has helped the progression of world records may soon be known, however, as high throughput microarray-based epigenetic technology, which allows DNA profiling, will soon be widely available.

The introduction of professional coaching, improvements in training techniques and the introduction of ergogenic aids – substances used for the purpose of enhancing performance, in the form of nutritional supplements for example – have also profoundly changed sports performance. Investigating the science of running economy has greatly improved long distance running, while the Fosbury flop technique (see video below) improved high jump performance.

Reaching a peak

If these considerations are true, then limits will be approached, and a point will be reached, perhaps soon, when performance levels become essentially static, with only the occasional, once-every-generation “super-athlete” able to set new records. Indeed, this situation may have already been reached in some events, such as the long jump and short distance runs, as progression of world records in these events has nearly stopped or has substantially slowed.

Doping practices might also have played a role in the progression of some world records. Also, the greater the role that equipment and technology plays a part in a sport, the greater the likely ongoing improvement. Thus, ergonomics/wind resistant clothes and better running shoes have enabled runners to optimise energy consumption.

The performances of athletes are the product of genetic endowment, hard work and, increasingly, the contribution of science. The latter began many years ago, when scientists, physiologists, nutritionists, biomechanists and physicists began applying their knowledge to the benefit of athletic performance. As a result, merely practising a sport for hours is no longer enough to enable an athlete to win.

Future limits to athletic performance will be determined less and less by the innate physiology of the athlete, and more and more by scientific and technological advances and by the still evolving judgement on where to draw the line between what is “natural” and what is artificially enhanced. A previous study determined that by the year 2007, world records would have reached 99% of their asymptotic value, which represents the limit for human performance.

Although world records initially progressed according to a linear model in the Olympic disciplines of track and field athletics, in most instances the progression curve has flattened out over the past 20 years (for example, in running and jumping), while in some sports (for example, shot put) no improvement has been recorded since the mid-1990s. Hence, if the present conditions prevail for the next 20 years, this will support the hypothesis that most of the male world records will probably no longer be substantially improved, although some female world records can still be expected to be broken, given increased access and participation.

Nevertheless, if gene doping happens, we may never be able to predict what the limits of human performance are. The probability is that further improvements will be mostly due to chance (occurrence of “extreme outliers” in the normal distribution of top-class athletes), the use of mechanical aids, the introduction of genetic or other forms of doping and, finally, environmental and ecosystem revolutions (pollution, for example). These would probably make any current mathematical model unreliable for forecasting progression of world records in athletics.

Friday, August 12, 2016

What's the TFA? Dateline; Torun, Poland

Zbigniew Rasielewski, Deputy Mayor, Torun
In a nutshell, it's the Toughest Firefighter Alive. Unlike the Scott Firefighter Combat Challenge, the four stages are built around the assets of the host.

For example, in Torun, the first evolution involved rolling up hose and dragging sections of LDH for time.

Another station included moving huge Jerry cans up and over obstacles, then crawing across wood spans and dragging Rescue Randys around pylons.

A third station involved moving straight ladders to the tower and positioning them for climbing, then carrying very heavy weights up the Challenge tower. The last of the four exercises was can only be called an "ass kicker."

I was invited to do a celebrity run against the deputy mayor of Torun. Thinking that this had to be a cake walk, I said, "Sure, why not?" I thought that this was more of a celebrity photo-op kind of thing. Then, "Can you do it in gear?"
The 450m Hose Shuffle

"Sure." So, I got sized for a bunker coat; that fit. Then held up the pants. "Yeah, that'll do. What about boots?" Brand new structural boots. "What size?"

Forty-one. Umm. "Let me try them on." Depending upon brand, 42, but, without socks, they'll work. Robert loaned me his helmet.

At this point, I haven't even asked what we're going to do.

Approaching the Finish
So, it's Saturday morning, and they'll telling me that we need to get ready. The Deputy Mayor looks like he just walked off the Soccer pitch. He's 6’6”, 30 years my junior and about 8% body fat. Alright.

I get into my gear, only to find out that the pants are flannel lined and they don't fit. But, they have suspenders. I'm ready to go. No, wait. You've got to wear a SCBA and this tank is about 40 pounds. Where's a Scott Air-Pak when you need one. Now, I'm set. "What this all about?"

Well, you're going to pick up two bundles of attack line and run 450 meter to Town Hall.

On Top with the Deputy Mayor

So, we're off. "Don't wait for me," I say to my comrade. But he does. I plod along, nodding to the many spectators who are taking photos and cheering us on.

Upon arriving at the Town Hall, we jettison the hose. Now, climb the tower. I have no clue as to how tall this building is and don't want to look up. So, we start into the stairwell. After what should have been the top of the FCC Tower, I ask, "How much farther?"

Dirk Fuhrman joins me at the top
"One more flight." and then "One more flight" and then "One more flight."

Janusz Wozniak, Chief Officer in the District
provided me with photos and video-
and encouragement

One of the rewards for all the hard work
The Tower is 69 meters tall. When I bust out onto the balcony the view of this ancient city is breathtaking- not that I'm not already breathing hard. I suck down as much water as they have available and spend the next 20 minutes checking out the view.

All in all, it was worth it. Next year, however, I'm going to do a little more stairclimbing training.

Torun's Fire Chief Kazimierz Stafiej
presented me with a
limited edition of a Polish beverage

Friday, August 5, 2016

The Cal Ripkin of the Firefighter Combat Challenge®

From Walt White, 25-Year FCC Veteran
The “Original” American River Combat Challenge Team with then Private Walt White on left next to Dr. Davis
This year marks the 25th anniversary of the SCOTT Firefighter Combat Challenge, an international competition that attracts over 5,000 competitors from 16 countries from around the globe, annually converging to compete for the title of World’s fastest firefighters. The event, known as the toughest two minutes in sports is aired on ESPN; it promotes fitness in the fire service and showcases to the general public the arduous demands of firefighting. Pairs of competitors, wearing full protective gear and self-contained breathing apparatus (SCBA)s provided by SCOTT Safety, race against each other and the clock through a series of five linked firefighting tasks: climbing a five-story tower, carrying a hose pack, hoisting a hose roll to the top of the tower by rope, driving a steel I-Beam a distance of five feet using a 9lb shot mallet to simulate cutting a hole with an axe, then competitors must drag a 1¾” charged hose line 75 ft. before hitting a target and lifting a 175lb victim mannequin and dragging it 100 ft. to the finish line. Top competitors will complete the course well under a minute and a half.
Walt running the course

Walt White: Lion’s Den Inductee 2011
One of this year’s competitors is Sacramento Fire Chief Walt White, competing for his 25th consecutive season, the only competitor to do so, compete in every season of the sports history. White, a self-proclaimed historian of the sport; he can name every year’s top finisher and their finishing time. Although not a World Champion himself, he has trained with and competed alongside some of the sports elite. He has competed in virtually every division of competition: open individual, team, chief, over 40, over 45 and this year he will be competing in the over 50 division. Twice White’s teams have finished third overall in the World. Individually he has won regional championships in the open division, held the over 40 state championship, he is a two-time national champion in the chief division and finished second in the World in that division in 2009. “Up until the last few year’s I always felt that my best run was still in me, now I am grateful for the age divisions and glad when I break the two-minute mark on the course. This is one sport where father time is undefeated” White says.

Chief Walt White, Sacramento Fire
Over the last 25 years White has worked his way through the ranks of the fire service from firefighter to fire chief. Additionally he has earned academic credibility by completing his: B.S. in Fire Service Management from Sacramento State, his M.S. in Executive Fire Service Leadership from Grand Canyon University, furthermore he completed the National Fire Academy’s Executive Fire Officer program and participated in both Harvard’s National Preparedness Leadership Initiative and the Naval Post Graduates Executive Leadership program. In July of 2014 he was appointed Fire Chief of the Sacramento Fire Department, the first person in the history of the department to be appointed to this post from the outside. As Fire Chief he has hired over 100 new firefighters and added companies, he is overseeing the replacement of two fire stations, has completed a Standards of Cover study, developed a 5-year master plan for the department and established a Diversity Advisory Board. “I am humbled and honored every day to serve as a fire chief and to work and compete with the best the profession has to offer”.