A group of scientists working for the National Institutes of Health recently developed a scientific study aimed to understand the relationship between the biological process of shivering and exercise. Humans have two different types of fat in their body: brown fat and white fat. Brown fat has the ability to burn calories and generate heat, unlike white fat, and was thought only to exist in children until recently. Scientists thought that shivering was the replacement for the heat-generating brown fat. It was not understood why two processes that perform the same function would exist.
Enter a hormone called irisin. Irisin is produced as a result of muscle contractions meaning that irisin production is greatly influenced by exercise and movement. A previous study performed on mice concluded that the production of irisin was directly related to the amount of brown fat in mice. This is because irisin’s function is to convert white fat to the more coveted brown fat. This study resulted in the scientists at NIH researching the hormone to locate its biological origin and purpose.
To conduct their research, the scientists drew blood and acquired muscle and fat cells from ten adult men and women on three separate occasions. On two occurrences, the test subjects performed a specific exercise in a room set to 65 degrees. In the first test, the subjects peddled on a stationary bicycle in full force until exhaustion. The second test had the subjects ride at a comfortable pace for a full hour. Shivering was induced in the third examination where the subjects wore light clothing and laid on a bed while the researchers dropped the room’s temperature form 75 to 53 degrees over thirty minutes. Monitors were used to record the subject’s skin and muscle responses.
This data obtained in this study supported the scientist’s theory that shivering, as well as exercise, is a conductor of irisin production. The subject’s blood samples showed that the amount of irisin in their blood was substantially increased after both tests performed on the bike. Surprisingly, irisin levels after lying in the cold room for thirty minutes and not moving a muscle, only shivering, were equal to those after physical exertion on the stationary bike. Therefore, muscular contractions, rather than intensity of physical exercise, are the true factor influencing the creation of irisin. Whether a person obtains these muscle contractions through exercise or standing outside in the cold for a short time does not matter.
Another weakness in the experimental design was that the reliability of the experiment was very low. As each test subject was only tested against each amount of prior exercise once, the impact of random errors is likely very large, which can be seen by the spread of the data on the graph. Although, this was attempted to be rectified by averaging the results of all four test subjects, it does not improve reliability too much. Conclusion: The results of this investigation indicated that a relationship between the amount of prior exercise and muscle fatigue does exist, however the results are also not conclusive enough to speculate on what the relationship is. This means that the hypothesis “If the amount of time spent performing vigorous exercise prior to the set of repetitions increases, then the physical performance (number of repetitions) will decrease” cannot be supported or rejected due to the inconclusive data.
In this experiment mice were studied as examples of organisms that employ physiological mechanisms to maintain and regulate internal body temperature.
In order to begin this lab procedure, the class was first split into lab groups of four. A meter measuring tape was then obtained from the lab materials. One member of the lab group sat on the edge of the table and the other members took turns measuring the circumference in centimeters at the widest part of the calf. The measure was taken by each lab member and recorded in a table. This step was repeated for each lab member in order to gain enough information for the data to be significant. After obtaining the circumference of each group members’ calf, a caliper was used to take the skin-fold thickness on the inside of the lab member’s ...
In this lab, we explored the theory of maximal oxygen consumption. “Maximal oxygen uptake (VO2max) is defined as the highest rate at which oxygen can be taken up and utilized by the body during severe exercise” (Bassett and Howley, 2000). VO2max is measured in millimeters of O2 consumed per kilogram of body weight per min (ml/kg/min). It is commonly known as a good way to determine a subject’s cardio-respiratory endurance and aerobic fitness level. Two people whom are given the same aerobic task (can both be considered “fit”) however, the more fit individual can consume more oxygen to produce enough energy to sustain higher, intense work loads during exercise. The purpose of this lab experiment was performed to determine the VO2max results of a trained vs. an untrained participant to see who was more fit.
In 1994, Zhang et al discovered the Ob gene and the hormone leptin1. This brought about the idea that obesity might have genetic-related factors and may not simply involve lack of self-control and overeating in the individual. The Ob gene regulates the amount of body fat storage in the body2. When the Ob gene signals, the hormone leptin is secreted from adipocytes1 and it travels to the hypothalamus in the brain2. This signals the hypothalamus to induce a feeling of satiety2. In other words, leptin secretion causes the stomach to feel full and ceases the necessity for eating. Once this discovery was made, the idea of obesity treatment came into play. If a hormone with satiety-inducing effects can be utilized for treatment then obesity may possibly become a null issue. Unfortunately this is an issue that still stands today – 20 years after the discovery of leptin.
...ghest in type I muscle fibers, average in type IIa and lowest in type IIb. It was also observed that there was significant difference between groups, where lipid content was ~25-50% higher in muscle from type 2 diabetes and obesity than normal subject, Lipid content intensity in muscle was ~40-50% higher in obese and type 2 diabetes than normal subjects.
The extra heat produced during metabolic exchange, raises the body temperature again affecting the enzymes and heat is then removed by sweating. If the body isn’t kept hydrated during exercise, dehydration will occur, causing the blood to become concentrated. When the blood becomes concentrated, the cells no longer have enough water to function.
Notably, physical inactivity has been identified as the fourth leading risk factor for global mortality, resulting in 6% of deaths globally (http://www.who.int/dietphysicalactivity/pa/en/: last accessed on 30 April 2016). Characteristically, public health practice addresses the physical activity and exercise in a broader sense, focusing on the communities, populations and settings. On the other hand, due to the advancement in healthcare technologies, Clinical Exercise Science has made it possible to incorporate physical activity and various exercise modalities into healthcare practice in a way that a response at organism (e.g., humans, animals), organ system (e.g., musculoskeletal system, nervous system, cardiovascular system, respiratory system), organ (e.g., heart, skeletal muscles, bones), and cellular (e.g., immune system cells, red blood cells) level can be examined, both in healthy people and patients with acute or chronic clinical conditions and disabilities. However, body of scientific evidence generated through the research in Clinical Exercise Science has its implications not only in clinical practice, but also in public health practice. This is one of the main reasons why I would like to join the Clinical Research Science Ph.D. program at the Potsdam
* Age of the person exercising * level of fitness and recovery rate * gender of candidate * temperature * amount of recovery time KEY VARIABLE: - The variable that I will be using is the duration of exercise, this is because it is easy to measure against any candidate and get a correct accurate reading from it. If I chose the type of exercise I will get readings that might not be correct because some types of exercises are
Investigating the Effect of Exercise on the Heart Rate Introduction For it's size the heart has the huge capacity of pumping large amounts of blood, in the average adult's heart beats 60 to 100 times a minute, pumps between 70ml and 100ml of blood with each beat, circulates 5 to 6 litres of blood around the body per minute and about 13 litres of blood per minute during vigorous exercise. The heart will beat more then 2.5 billion times during an average lifetime. This investigation will be looking at the effect of exercise on the heart rate. Aim The aim of this investigation is to find out how exercise affects the heart rate, using research & experimenting on changes and increases in the heart rate using exercise. Research â— The heart The normal heart is a strong, hardworking pump made of muscle tissue.
As humans we need the heart to pump blood all around the body in order
Sweating and Heat Loss Investigation Aim To find out whether heat is lost faster over a sweaty body compared to a dry body. Apparatus 2 Boiling tubes 47ml max 2 Measuring jug 50ml max A Beaker 250ml max 2 thermometers Paper towels A kettle to boil water A stopwatch 2 magnifying glasses (8x) 2 corks with a small hole through the centre A test tube rack Preliminary work In my preliminary work, I need to find out how much water to use, whether the tissue should be wet with hot/cold water, how often the readings should be taken, how accurate should the readings be, how many readings should be taken and what my starting temperature should be. My results are as follows. Starting temperature of 40°c Time (secs) Wet towel (°c) Dry towel (°c) 30 36 38.9 60 35 38.5 90 34 37.9 120 33.9 37.5 150 33 37 180 32.6 36.9 210 32.3 36.8 240 31 36.5 270 30.4 36 300 30.3 35.9 Starting temperature of 65°c Time (secs) Wet towel (°c) Dry towel (°c) 30 51.1 53 60 48.2 51.9 90 46.4 51 120 46 50 150 44.3 49 180 42.9 48.4 210 42.6 46.9 240 41.7 48 270 40.2 47.5 300 39.3 47 Starting temperature of 60°c Time (secs) Wet towel (°c) Dry towel (°c)
Many factors can influence the results of testing this hypothesis. All variables have been controlled except for the variable gender. Both the male and female subjects are close in age (< two years difference), both are nonsmokers, both possess small body builds for their respective gender, and both have no debilitating medical conditions (e.g., asthma, diabetes, heart condition). Controlling these factors allowed for the testing of the hypothesis, which is focused strictly on gender.
body has to work harder I think that the heart will then increase at a
Orloff, Judith. The 4 Laws Of Energetic Attraction. Natural Health 34.5 (2004): 98. MasterFILE Premier. Web. 20 Mar. 2014.