Throughout The Sports Gene Reading this week, I wanted to focus on the author’s thoughts on race and muscles fibers. He starts off by mentioning the physical differences between Europeans and Jamaicans. Studies have shown that Jamaicans have longer legs relative to body height and slimmer hips. This is backed by Bergmann’s rule saying that “humans with recent low latitude ancestry will also tend to be more narrow, with slimmer pelvic bones” (pg. 175). The point of these differences was to ultimately look at the reasons behind the running speed scales where both of these physical features proved to be beneficial. However, Epstein found a more anatomical approach by hypothesizing that “malaria in western Africa forced the proliferation of genes that protect against it, and that those genes, which reduce an individual’s ability to make energy aerobically, led to a shift to more fast-twitch muscle fibers, which are less dependent upon oxygen for energy production”. (pg 176)
Cooper found hope in this theory with a 1986 study from Laval University in Quebec published in the Journal of Applied Physiology. The scientists took muscle samples from the thighs of sedentary students , primarily from countries in West Africa. They took the same samples from two dozen sedentary white students who were identical to the African students in age, height, and weight. The results showed that “a higher proportion of muscles in the African students was composed of fast-twitch muscle fibers, and a lower proportion was slow-twitch muscle fibers compared with the white students. Furthermore, these results showed that the African students had a significantly higher activity in the metabolic pathways that rely less on oxygen to create energy and that are engaged during an all-out sprint”. (pg. 179) This directly relates to the metabolic pathway topic review in class as we were discovering the differences between aerobic and anaerobic exercise. If the study showed that these students had metabolic pathways that rely less on oxygen to create energy, they may be more naturally inclined for sprinting since their bodies naturally choose an anaerobic pathway that doesn’t require oxygen.
In my opinion, I think this is an important study to look into as genetic factors can place people into categories where they may be more successful in certain sports. However, this chapter comments on several scientists who have no interest in investigating it because of the inevitably thorny issue of race involved. (pg. 185) When our class held a similar discussion about the topic, it came down to whether you would want to know which sports you would thrive in as a child or merely have the freedom to choose your sport/activity based on your love of the sport. Would your parents be more inclined to steer their child towards a sport if they knew they succeed? A study by Lisa Guth showed that “A favorable genetic profile, when combined with an optimal training environment, is important for elite athletic performance; however, few genes are consistently associated with elite athletic performance, and none are linked strongly enough to warrant their use in predicting athletic success.” Therefore, it seems there are a difference of opinions on whether or not genes do play an important role in athletic success. Personally, if I had known I had the potential to be a star tennis player when I was young I would have pursued it. I would be interested to see how my own muscle fiber type relates to the success in certain sports and tweak my training based on that. However, to each his own. However, it seems there is a future of correlating athleticism with genetics that may even change the way we look at sports one day.
David Epstein, The Sports Gene. Chapter 11, Pages 175-185.
Identify: Many people today look for ways to track their workouts to make sure that they are getting the best possible results whether it is for weight loss or training performance purposes. From high intensity interval training to slow jogging, heart rate monitors have proven to be popular in assisting users with how well they are performing. Furthermore, there are different types of heart heart monitors that are on the market today including chest straps and wearables that have proven to be successful. However, each different type of heart rate monitor has a slightly different method of measurement. So, lets take a peek into how these devices work.
Chest straps are one of the most popular and well known forms of a heart rate monitor that is used today. These straps use a wireless sensor to detect your pulse electronically and then send that data to a wristwatch-style receiver to display. Although these are deemed to be the most accurate, they are not the most comfortable to wear during a workout. Therefore, wearable wrist heart rate monitors have been developed which use an optical sensor built into the wrist unit’s watchband or case back to detect your pulse in a more comfortable way during your workout. The downside to these devices is that they are less accurate than a chest strap. Therefore, we can take a look into how to design an optical sensor that has the most accuracy possible for wearable HRM (heart rate monitor) devices.
Formulate: The main issues that have caused a lower accuracy and unclear signal in wearable HRMs have been the noise, weakness of the measured signal, amplitude of motion, and wide variance between different peoples’ wrists. To look into resolving these issues, it needs to be understood how these devices work. Optical HRM sensing is based on the principle of photoplethysmography (PPG). This allows the wristband to relate the pressure pulse from blood vessels as blood is passing through to each time a heart beats to get the heart rate. The way it does this is by using an LED to emit light into the body’s tissues and and use photodiodes to measure the amount of light that passes through them. The difficulty with this technology is that the measured signal is very small. In order to make a more accurate heart rate monitor, we want to be able to record the signal with the least amount of noise around it due to motion.
The most effective way for reducing the noise is simply the position of the wearable HRM in reference to the skin. The band needs to be worn with a snug fit and maintain an unchanged position throughout a workout. In the figure below, you can see the different interference levels depending on the gap between the skin. On the left, there is more interference shown by more blue lines and on the right there is less interference due to the proximity that the sensor is to the skin.
It is also important to understand that there are other factors that can cause interfere with a wearable HRM to decrease accuracy. For example, wrist curvature, wrist hair density and color, and skin color can all affect an optical signal’s reading. Skin color is a factor of great interest due to the fact that it greatly affects the signal and requires a change in LED brightness. Between the physical gap and skin tone, both factors are large determinants of accuracy for a wearable HRM.
In order to design an optical sensor. We will want to minimize the gap between the sensor and sin but also include a sensor that can accurately read a signal with various skin tones.
We can use this equation for photocurrent by breaking it into AC and DC components of the signal. Typically, there might also be ambient light present (AC + DC noise). However, “the DC component of optical noise is usually subtracted due to an ambient light measurement immediately prior or after the LED light on measurement, resulting in an effective signal of”:
In today’s day and age, many stores selling athletic wear advertise “dry fit” and “sweat resistance” clothing to the public as the best clothing for your workout. This material, also known as moisture-wicking clothing, is known to keep the sweat away from your body and help you feel dry during a workout. Nike, for example, has an entire section on their website devoted to sweat-wicking clothing which seems to be a common trend in stores selling athletic wear. Therefore, this may be the reason why you’ve seen a change in apparel in those morning joggers from their favorite college hoodie to a dry-fit quarter zip.
Many people from scientists to bloggers have discussed the idea of moisture-wicking clothing and its increasing popularity in today’s population. One distinction discussed by Shape explains the types of material deemed as “moisture wicking” and the differences between each. Put simply, they explain to consumers when to wear what material from nylon to bamboo. Others have focused on the effect of the moisture wicking clothing and how it affects performance. Consumers Digest , for example, looked into whether these materials actually made an athlete feel more “cool and comfortable” during exercise and therefore improved their ability to complete a better workout. Their findings stated simply that “these shirts might make you feel more comfortable and look trendier at the gym, but we remain unconvinced that they’ll help you to breathe more easily, run longer or lift more weight”.
Despite the many different viewpoints on the internet, it seems that the athletic wear industry still thrives on selling moisture wicking clothing to the general public. However, the unanswered question seems to lie in the scientific research on how moisture wicking materials affects the thermoregulation process in your body when you exercise. AKA, how is this clothing helping to keep our bodies dry and preserve our body temperatures as we exercise without disrupting its natural cooling process of sweating? To begin, we can take a look into the science behind moisture wicking materials and how they work.
In a study through Western Michigan University, they investigated the effects of wearing a form fitted, moisture-wicking shirt on body temperature during acute exercise. The study showed that after 45 minutes of exercise (50% VO2peak) in a hot environment, heat stress tests showed a significantly lower temperature (P<0.05) while wearing the synthetic material (81% polyester and 19% elastane) during the last 15 minutes of exercise as compared to wearing a 100% cotton shirt. From this, they were able to infer that as the exercise duration increases, the ventilation and evaporation properties of the clothing garment helped to preserve body temperature during exercise in the heat. The limitations of this study, however, include that the sample size was of 10 males. Expanding this study to both genders could alter the effects. In addition, only one moisture wicking garment was used. To expand this, they could test different variations of synthetic material in order to see which combination has the greatest ability to preserve body heat under exercise conditions.
Eastern Carolina University reported that “the major dilemma is the dissipation of the heat produced from muscular activity”. They found that clothing acts as a barrier to heat transfer and evaporation from the skin. However, research suggests that the clothing fabric did not alter the thermoregulation or thermal comfort during exercise in warm conditions. The only distinction they were able to make was that the clothing fabric altered thermoregulation during and following exercise in a cold environment where sweat was able to be separated from the body. Limitations mentioned included that they “should include conditions that more closely mimic outdoor conditions, where high work rates, large airflow and high relative humidity can significantly impact thermoregulation”.
In conclusion, moisture-wicking clothing still seems to be a bit of a mystery to us all. Despite research that questions its validity to aid in thermoregulation, the industry still seems to thrive based on the fact that the fabric can take the moisture away from your skin. What we can say is that this material will help keep you dry during exercise and help to keep your body temperature stable in cold environments where sweat would’ve had a chance to act as a “cold sheet” on your body. However, additional research needs to be done to specify using moisture-wicking clothing with different types of exercise, in different humidity conditions, wind velocities, and temperatures in order to pinpoint the exact details of its effect on thermoregulation.
The Office Gym Exercise kit is a an exercise kit that can be attached to multiple different chairs in order to provide exercises to the user. The kit comes with a flexible body that can be wrapped around the post of a chair in order to “ground” the system. In addition, it comes with an elastic band, two elastic straps, an ankle attachment, various attachable handles, and a means of latching the system to the chair. The kit is shown set up and in use in Figure 1 below. In addition to the contents of the kit, the major claims of this patent highlight the materials that each of these components contain and how to use them. For example, claim 7 explains that the strips provided are nylon and claim 6 explains that the plurality of retainers are D-rings.
I think this technology would be very applicable to all of the working citizens with desk jobs. A major issue that companies face with their employees is the health risk of sitting in a chair all day. After working at a desk job for an internship this summer, the company sent around an Ergonomics expert to analyze our posture and computer placement to make sure that our set up wasn’t causing any pain to us as we worked. In addition, they recommended that we get up and walk around ever hour or so to get moving and take a break from starting at a computer screen. This can help prevent blood clots and keep your energy up throughout the day. Therefore, this technology provides an alternative by having a kit that is attachable to your chair to provide exercise throughout the day. Employees would be able to take breaks, use different body parts for different movements, and be somewhat active throughout the day.
The exercise kit functions by attaching a flexible body to the post of a chair with elastic straps in order to provide tension to the system. Due to the flexibility of the body material, this apparatus can be applied to a multitude of chairs In addition, a back attachment is provided in order to circle around the chair and lock the provided elastic straps to the base of the chair. The elastic straps are connected to a retainer through a latching system to provide a tight grip on the chair. The retainer provides various points of attachment depending on how long they need the elastic strap to be. Therefore, the user is then able to exercise their arms, legs, and back by pulling on the straps and providing resistance to their muscles. Each of the elastic straps has a D-ring attached for easy grip and handling.
There have been similar patents in the past with this idea, however they all differ from this specific patent slightly. For example, Patent No. 5,690,594 issued in 1997 describes a similar apparatus that can be attached to a chair. However, this patent includes a foot support bar to allow users to extend their foot along the bar. In addition, wheels are mounted to the food support and the user is able to push the foot support bar away from the user and back in order to exercise. In addition, Patent No. 5,599,260 issued in 1997 covers an exercise kit that attaches a roller to the post of a chair via an elastic material. This way, the device can exercise the user by with either their foot or their arm depending on where they attach the element. Furthermore, Patent No. 6,099,445 issued in 2000 describes an exercise device that includes a rigid framed with elements that can be attached to it. The frame can be attached to the central back of a chair and allow the user to exercise their arms, legs, and neck. Therefore, although there are similar patents on the market, there are slight differences between each of them that distinguish their patents from each other.
This patent caught my eye as it is a simple idea that has yet to be implemented into any office that I have heard of. As I mentioned previously, I have experience working a desk job in which they warn you about the lack of movement throughout the day if you do not get up and walk around every now and again. This is a risk to both employees and a company who provides health insure to their employees. Therefore, I figured this kit is an interesting initiative to increase fitness motivation throughout an office environment. In addition, the components that make up this kit are not technology heavy. They are made of normal exercise equipment materials that can most likely be provided at a fairly reasonable price for companies.
Figure 1.) This image shows the kit set up to a desk chair, as described, and in use.
Although exercise can provide many health benefits, many people look at it as a simple way to help them lose weight. However, intense exercise may seem daunting to populations who are new to exercise or recovering from injury. Therefore, the question arises of whether it is possible to lose weight with low intensity exercise. In this news article, published by The Telegraph, they take a look into each form of exercise and how they effect weight loss.
The author, Lucy Waterlow, claims how “the HIIT philosophy has been behind every new exercise class, bestselling book and rising YouTube fitness star” The fitness acronym stands for High Intensity Interval Training and typically requires you to keep your heart rate at at least 85% of its maximum capacity throughout the workout. However, for people with injuries of any kind this method of exercise is a bit more difficult. Therefore, LISS has been heavily emphasized as of late as being the new and improved way to keep your weight under control and putting less of a strain on your body. LISS stands for Low Intensity Steady State and requires you to keep your heart rate between 60-80% of its maximum capacity.
The article references arecent study by the University of Bath, which found that “LISS can be just as effective as HIIT when it comes to weight loss”. Theses results came from a study in which they asked people of a similar age to exercise five times a week at either high or moderate intensities. Their results showed that after a three-week period, both groups had lost the same amount of weight. Dr Jean-Philippe Walhin, a human physiology research fellow who carried out the study, quotes ‘What really matters is how many calories were used up by exercising in total.’
The articles continues with an additional argument claiming that LISS may motivate people to work out more since it isn’t as stressful on your body. This way, you are able to increase your physiological health and motivation at the same time without the high risk of injury that may occur with High Intensity Interval Training. In conclusion, the article highlights the benefit of LISS workouts and how they are comparable to HIIT workouts in weight loss.
I believe this is a relevant article to the Engineering Exercise course as it looks at two different, popular types of training and how they affect weight loss. Although “the best way to lose weight” will always be a hot topic, I think it is important to recognize that different exercises are better for different people based off of their medical history.For example, the idea of going to the gym for a cross fit class may scare someone who is obese out of working out at all. But, the idea of 45-minute brisk walk may appeal to them more and benefit them physiologically rather than not working out at all. It becomes a cross between physical therapy, where exercises are designed for the individual, and research, where the latest and greatest ideas for weight loss are tested.
In my opinion, I thought this article was interesting in its approach to the general public but was lacking in the hardcore data. However, I felt this is expected in a “Lifestyle” piece and found it interesting to see how referencing studies and quoting doctors may be enough to convince the general public about health and fitness, regardless of whether hard data was presented. When I looked into the argument of LISS vs. HIIT workouts further, I found a source that provided more detailed information to prove their points and support their argument. In Martinez’s “Cardio for Fat Loss“, he focuses on the pros and cons of each kind of training and how they benefit you in weight loss. I found this to be more beneficial than the original article as it stated straight facts about both, and let the reader decide which is better for their situation. The underlying conclusion was that “HIIT is quicker, proves to be more effective for fat loss, creates metabolic changes, and helps with muscle retention but not everybody can do HIIT. LISS is safer, but takes twice as long to accomplish similar things and it still has its place for fat loss in moderate amounts, from a pure calorie burning standpoint (meaning only to burn calories & not make changes to your metabolism)”. This was helpful in looking at weight loss from a metabolism standpoint, rather than just pure fat loss. In conclusion, it is beneficial to know that despite differences, both HIIT and LISS workouts can lead to some form of weight loss.