In both his Ted Talk , Are athletes really getting faster, better, stronger?, David Epstein, the author of The Sports Gene, delves into the impacts that technology has made in many different sports. Tennis racquets and track surfaces were just a few he explained, but the one that caught my attention was the development of racing swimsuits. Unlike the other advancements, new swimsuit material was actually banned in 2010 for “distorting the sport”.
In this Daily Beast article, based on his book, Mathletics: A Scientist Explains 100 Amazing Things About the World of Sports, John D. Barrow explains why these suits were banned and the technology of how they worked. While logically people know water causes more drag than air (sprinting splits are faster than swimming splits of the same distance) it is astounding how much more. Water, according to Barrow, causes 780 times more drag. This obviously is not ideal for swimmers, so the whole-body polyurethane suits were able to trap small pockets of air that increased the swimmers buoyancy. Essentially, the more of their body that is above the water the less drag thats created. These suits became especially popular after Michael Phelps’ 8 gold medal run of the 2008 olympics. The next summer, 9 world records were broken by swimmers wearing these suits. People began to question whether they were fair with some swimmers threatening to stop competing. Michael Phelps claimed he would boycott all international events until they were banned. So with the threat of losing their top athlete the olympic committee took it to a vote and the suits were banned almost unanimously.
The reason this debate is interesting to me is that it raises the bigger question: Where do we draw the line in sports technology? I understand that the idea of sports is to compare one athletes ability to the next, but if they are both wearing the suits who cares? But on the other end, the sport was quickly headed to an arms race of technology rather than hard work and training. This has made me extremely interested in sports technology in other sports.
In today’s world of social media “fitspo” blogs and fad diets are at our fingertips more than ever. The “recommended page” on Instagram, for example, is full of fitness bloggers telling you exactly what to eat and what work outs to do for the best results. And while their advice is often based on some truth, it is also can be blown out of proportion or can be easily misconstrued. It is important to remember that diet is based on individual needs and that what works for one person may not work for you- therefore, the best way to choose new meal plans is through education. First off, why are proteins so important?
Figure 1: 9 essential amino acids we must ingest.
Proteins have four layers of structures that all play a role in how they work and how they interact. The primary structure, is simply the sequence of amino acids (AAs) in a polypeptide chain. There are essential AAs that we must ingest, non-essential AAs that our body can produce, and conditional AAs that are pertinent in times of stress and illness. Protein is extremely beneficial and unarguably critical to our diets, we excrete excess amino acids, so over eating protein poses to additional benefit.
So knowing this, how do you decide how much protein you should eat? Maybe to some surprise, science have shown that athletes actually require the same general range of protein intake when compared to sedentary persons of the same sex. According to the U.S. and Canadian Daily Reference Intakes,0.8 g·kg−1 of protein is enough to meet the needs of 98% of healthy adults. “There is not a strong body of evidence documenting that additional dietary protein is needed by healthy adults who undertake endurance or resistance exercise, the current DRI for protein and amino acids does not specifically recognize the unique needs of routinely active individuals and competitive athletes.” They also suggest that for adults 18 years and older, 10%-35% of total caloric intake should be comprised of protein. This supports the accepted ideal that the recommended intake levels can be met through regular diet and without supplementation.
What does this mean for those trying to lose or gain weight? Whilst, in both of these cases, it may be easy to fall victim to one of the fad diets, you should take the time to understand them and to find the truth behind them. CrossFit is currently one of the most popular fitness plans and many of their athletes use meal templates to guide them in fueling their bodies. The Paleo Diet and Zone Diet are two of the most common choices for these athletes, or a combination of the two. Paleo (sometimes called the caveman diet) is bases on eliminating processed food and eating a high fat, moderate protein and low carb diet. The Zone Diet is based on “blocks” where you eat a specific number of daily servings of proteins, carbohydrates, and fats. The “blocks” are structured throughout the day rather than in the normal 3 meals a day. The diets claim to increase metabolism and when tailored to specific goals, can result in significant weight loss and muscle development.
Figure 2: The 40/30/30 breakdown of the Zone Diet.
Samuel N. Cheuvront found that the Zone Diet does not result in the promised outcomes. He found that any significant contribution of active muscle oxidation was not even found in skeletal muscle. In another investigation by Tipton, et al, they looked at the differences between ingesting protein (such as whey protein supplements) before weight training versus after. Their results allowed them to conclude that the timing of supplementation does not matter but that having protein in your system consistently does have positive impacts.
Based on the review of the current literature, the biggest conclusion that can be made is that protein does play a large role in diet and in over all health. What cannot be confirmed is the benefits of protein supplements or high protein diets. According to daily recommended intakes, it is much more important to have a balanced diet, and the main benefit of a high protein diet may actually be limiting sugar and carb intake.
For physical therapists, one of the most important and sometimes most challenging aspects of their job is to track patient progress during rehabilitation from an injury or surgery. While most of this can be done based on patient reporting (such as 1-10 pain/discomfort scales) or qualitative therapist observations, they collect quantitative data whenever possible. One of the most common ways therapists can document progress is through strength testing. For larger muscles, such as the quad and hamstring, larger testing apparatuses, like the Biodex, are used to measure strength. These machines, however, are large and difficult to use. They can be oriented for smaller muscles but almost always therapists will opt for hand-held dynamometers. Over the years these dynamometers have developed from simple spring or strain gauge contraptions to sleek digitalized devices.
The above dynamometers are used to test grip strength and for the sake of explanation I will focus on this orientation., It is important to note that clinics often use the device shown below to measure strength of the arm and shoulder region since it allows for measurements to be taken in many different directions. For example, knowing the internal rotation and external rotation strength of a baseball players injured arm in comparison to his healthy one will allow the therapist to decide when the player should be allowed to return to play.
As I mentioned, all of these devices are designed on the seemingly simple basis of springs and strain gauges, Therefore, when designing a dynamometers the starting point is to decide what spring to use. If the spring constant is not stable and known, the device cannot be calibrated and will not result in accurate readings.
For a grip strength dynamometer the patient pulls on a a handle connected to a spring of a known constant. Based on the displacement of the spring from it’s resting position the force they generated can be calculated. This force is a direct measure of grip strength. To decide the stiffness of the spring that should be used an engineer must use Hooke’s Law:
Hooke’s law states that the force of extension on the spring is proportional to the displacement of the spring.
The following assumptions can be used to calculate the max spring constant that should be used:
Force (Fs)– According to a study done by Top End Sports the maximum grip strength the dynamometer must be able to withstand is 57.5 kg.
Displacement (x)- Based on average hand sizes it can be assumed that the maximum displacement of the spring will not exceed 9 cm.
Fundamentally, stiffer springs have higher spring constants. For this reason, we know that the spring constant should be minimized, yet must be able to detect the max force and displacement it may experience. You essentially do not want to make it harder than it has to be for the patient.
Using these two assumptions and an understanding of Hooke’s Law it can be determined what the max spring constant that will be needed.
The following steps are used along with the assumed values to determine the ultimate spring constant:
57.5 N=-k(0.09 m)
According to these calculations, a spring with a constant below approximately 640 N/m will suffice in your design of a handheld dynamometer.
Now it is important to understand the implications of the assumptions made here so your design can be altered for maximum efficiency. It is necessary to consider the patients that will be using your design. While the calculations above are generalized for average sized patients this may not fit your needs. For example, if your device will be used by pediatric patients the assumed values can be much lower whereas if your device will be used by athletic trainers in professional sports, the numbers should probably be increased.
The development of such dynamometers has been on the rise as their clinical prevalence has also risen. They are extremely beneficial to clinicians yet are based on such a simple engineering principle.
For more information on the benefits and design of dynamometry I encourage you to check out the following readings:
If you have ever participated in little league baseball or softball you can probably vividly remember the pain of batting practice on a cold morning and the sting of your hands with every hit. With the traditional aluminum or wooden bats you most likely used, the sting from the vibration was something players came to expect. Today’s players, however, may never know the real extent of this pain with the introduction of composite bats. In short, this invention makes softball bats more energy efficient, enhancing their performance as well as comfort for the player using it.
Previously, metal bats were the most common bat. Compared to the wooden bats used before, metal bats were much more durable. Unlike wood, metal bats did not snap in half, but almost every hit left a dent of some size on the bat. Mechanically speaking, the bat is an accessory the player uses to transfer energy from their arms to the ball during their swing. The energy that is used to dent the bat, therefore, is energy lost from the actual hit and counterproductive for the player. Even if the dent is not visible, metal bats experienced microscopic cracks that ultimately failed due to shock loading. Surprisingly to me, metal bats failed after as few as twenty-five hits. That means that a brand new bat could fail in during warm-up and already be past it’s prime by game time. Patent US 20020198071 A1 proposed a composite bat where the inner reinforcement sleeve was aluminum, and was the biggest driver for this upgraded patent.
Figure A. An inside look at the multi-layer construction of the ultimately hollow bat barrel.
Of the 40 claims included, most are focused on the manufacturing of the bat-the molding of the inner sleeve and fusing of the handle- however, the composite material used is what makes it novel. US Classification 473/567 represents designs “of plastic compilation” which is the greatest improvement on already existing bats. The design of the bat, as shown in Figure A, is tubular “sleeves” concentrically aligned and the ultimately hollow barrel. Unlike the previously proposed “composite bats” this was the first completely composite design. The bat is “comprised of a continuous resin matrix reinforced with a plurality of circumferentially-extending fiber socks”. The fiber socks are comprised of, by weight, 74% fiberglass and 26% carbon fiber and enforced with nylon tapes. This design provides the ultimate level of strength with the added benefit of a flexible body. This elasticity of the barrel provides a “trampoline effect” where the bat acts as a springboard for the ball. The local deformation when the bat is in contact with the ball ultimately results in the maximum velocity of the ball by conserving energy rather than stealing it with a dent. The composite material allows the barrel to momentarily elastically deform into an oval and return to a perfect circle rather than denting and being permanently harmed.
This design will excite softball player across the globe. Unlike in baseball, softball players from age 5 to professional, are allowed to use metal or composite bats. Additionally, this design will benefit all players, not just the elite. In softball terminology, the composite material and construction of the barrel elongates the sweet spot that we all aim to find as a batter. As a smaller-framed softball player, I found this technology exceptionally interesting since anyway to enhance the power of my swing is greatly appreciated.