Spot reduction refers to the claim that fat in a certain area of the body can be targeted for reduction through exercise of specific muscles in that desired area. For example, exercising the abdominal muscles in an effort to lose weight in or around one's midsection. [1] [2] Fitness coaches and medical professionals as well as physiologists consider the claim to be disproved. [3] [4]
Over time it has become clear to trainers and health professionals that the idea of working out certain muscle groups, in order to burn fat in that specific area, is not possible. Advertisements, magazines, internet trainers, and social media continue to push the idea that exercising small isolated muscles, such as abdominal muscles, will help the fat above the muscles disappear. Fitness professionals say this is false, yet even trainers still use phrases like "burning fat" and targeting "troubled areas" like "muffin tops" to pull people in. These phrases are considered misleading to those trying to lose weight. Fat cannot physically "burn" off one's body. The burning feeling people describe when practicing resistance training is caused by the production and accumulation of lactic acid in muscle during exertion via the process of anaerobic respiration, and has nothing to do with the fat surrounding the area. Muscle development and improvement can be shown more easily in lean people. Those who are overweight have a better chance of reducing fat if they increase their overall fitness levels. This can be achieved by doing both high-intensity interval training cardio and resistance training that focuses on gaining muscle mass in both large and small muscle groups. This increase in muscle mass will create a larger need for energy that comes from fatty acids in stored fat cells. [1]
Although professionals know spot reduction is a myth, many people still believe that it is possible to choose where fat can be lost on one's body because of the continual misleading information fitness settings and the internet are providing. [1] The scientific consensus among fitness experts and researchers is that spot reduction is not achievable. This belief has evolved from the idea that gaining muscle increases metabolism, resulting in fat reduction. People think that fat loss in a specific region could be targeted by building muscle around it. [5] Studies have shown that it is not possible to reduce fat in one area by exercising that body part alone. [2] [3] [4] [6] [7] [8] Muscle growth in a region does not reduce fat in that region. [9] Instead, fat is lost from the entire body as a result of diet and regular exercise. [6]
All body shapes are different, meaning people carry fat in different places. Moreover, research suggests that variation in both overall adiposity and regional fat distribution is highly genetic. [10] Some locations on the body are more metabolically active than others, and those areas will lose weight quicker than those that are not as metabolically active. For many people, abdominal fat is more metabolically active and can be reduced easier than fat in the lower regions of the body. The reduction of these metabolically active sites is not due to an increase in abdominal muscle contractions. [11] While exercising, fatty acids are being mobilized due to the presence of hormones and enzymes. These create a negative energy balance in the body. Fat is reduced over the whole body. Exercise of certain muscles cannot signal a specific release of fatty acids for the specific fat deposits above those muscles being activated. [5]
In a randomized control study, scientists sought to determine a link between skeletal muscle size and surrounding fat on a specific body part when exposed to strength training. They compared the muscle and fat content of high-caliber tennis players' dominant and non-dominant forearms. The method used in this study to examine the amount of subcutaneous fat between the tennis players' arms, was a skinfold caliper. (There are a multitude of tests that can help determine body fat percentage). After measuring the two arms, they found that the girth of the dominant arms was greater because these muscles were used more than the non-dominant arm muscles. However, the skinfold measure showed no difference if the amount of subcutaneous fat on either of the arms. This proved that the muscles on the dominant arms grew due to hypertrophy of the muscle, yet the amount of fat surrounding the muscle on the dominant arms was not reduced from this increase. There was no proof of spot reduction taking place. [5]
In another randomized study, scientists divided 24 sedentary adults, ages 18–40, into an exercise group and a control group. The exercise group added 7 abdominal exercises, 2 sets of 10 reps each, 5 days a week, for 6 weeks, into their daily routines. The scientists discovered that at the end of the 6 weeks, through comparing a variety of endurance tests, body composition tests, and anthropometrics, the subcutaneous fat around the abdominal region did not shrink. However, muscular endurance of the core region did improve when comparing the before and after of the number of sit-ups between the post-study exercise group and control group. Therefore, even though an increase in muscular development of a certain region in the body took place, it did not remove the fat around the muscles. Again, there was no proof of spot reduction taking place. [2]
Insulin resistance (IR) is a pathological condition in which cells either fail to respond normally to the hormone insulin or downregulate insulin receptors in response to hyperinsulinemia.
Abdominal obesity, also known as central obesity and truncal obesity, is the human condition of an excessive concentration of visceral fat around the stomach and abdomen to such an extent that it is likely to harm its bearer's health. Abdominal obesity has been strongly linked to cardiovascular disease, Alzheimer's disease, and other metabolic and vascular diseases.
Lipolysis is the metabolic pathway through which lipid triglycerides are hydrolyzed into a glycerol and free fatty acids. It is used to mobilize stored energy during fasting or exercise, and usually occurs in fat adipocytes. The most important regulatory hormone in lipolysis is insulin; lipolysis can only occur when insulin action falls to low levels, as occurs during fasting. Other hormones that affect lipolysis include glucagon, epinephrine, norepinephrine, growth hormone, atrial natriuretic peptide, brain natriuretic peptide, and cortisol.
Adipose tissue (also known as body fat, or simply fat) is a loose connective tissue composed mostly of adipocytes. In addition to adipocytes, adipose tissue contains the stromal vascular fraction(SVF) of cells including preadipocytes, fibroblasts, vascular endothelial cells and a variety of immune cells such as adipose tissue macrophages. Adipose tissue is derived from preadipocytes. Its main role is to store energy in the form of lipids, although it also cushions and insulates the body. Far from being hormonally inert, adipose tissue has, in recent years, been recognized as a major endocrine organ, as it produces hormones such as leptin, estrogen, resistin, and cytokines (especially TNFα). In obesity, adipose tissue is also implicated in the chronic release of pro-inflammatory markers known as adipokines, which are responsible for the development of metabolic syndrome, a constellation of diseases, including type 2 diabetes, cardiovascular disease and atherosclerosis. The two types of adipose tissue are white adipose tissue (WAT), which stores energy, and brown adipose tissue (BAT), which generates body heat. The formation of adipose tissue appears to be controlled in part by the adipose gene. Adipose tissue – more specifically brown adipose tissue – was first identified by the Swiss naturalist Conrad Gessner in 1551.
Physical fitness is a state of health and well-being and, more specifically, the ability to perform aspects of sports, occupations and daily activities. Physical fitness is generally achieved through proper nutrition, moderate-vigorous physical exercise, and sufficient rest along with a formal recovery plan.
Basal metabolic rate (BMR) is the rate of energy expenditure per unit time by endothermic animals at rest. It is reported in energy units per unit time ranging from watt (joule/second) to ml O2/min or joule per hour per kg body mass J/(h·kg). Proper measurement requires a strict set of criteria to be met. These criteria include being in a physically and psychologically undisturbed state and being in a thermally neutral environment while in the post-absorptive state (i.e., not actively digesting food). In bradymetabolic animals, such as fish and reptiles, the equivalent term standard metabolic rate (SMR) applies. It follows the same criteria as BMR, but requires the documentation of the temperature at which the metabolic rate was measured. This makes BMR a variant of standard metabolic rate measurement that excludes the temperature data, a practice that has led to problems in defining "standard" rates of metabolism for many mammals.
Adipocytes, also known as lipocytes and fat cells, are the cells that primarily compose adipose tissue, specialized in storing energy as fat. Adipocytes are derived from mesenchymal stem cells which give rise to adipocytes through adipogenesis. In cell culture, adipocyte progenitors can also form osteoblasts, myocytes and other cell types.
The sit-up is an abdominal endurance training exercise to strengthen, tighten and tone the abdominal muscles. It is similar to a crunch, but sit-ups have a fuller range of motion and condition additional muscles.
The anthropometry of the upper arm is a set of measurements of the shape of the upper arms.
The body fat percentage (BFP) of a human or other living being is the total mass of fat divided by total body mass, multiplied by 100; body fat includes essential body fat and storage body fat. Essential body fat is necessary to maintain life and reproductive functions. The percentage of essential body fat for women is greater than that for men, due to the demands of childbearing and other hormonal functions. Storage body fat consists of fat accumulation in adipose tissue, part of which protects internal organs in the chest and abdomen. A number of methods are available for determining body fat percentage, such as measurement with calipers or through the use of bioelectrical impedance analysis.
Weighted clothing are garments that have heavy materials incorporated into them, to add weight to various parts of the body, usually as part of resistance training. The effect is achieved through attaching weighted pieces to the body which leave the hands free to grasp objects. Unlike with held weights or machines, weighted clothing can leave users more able to do a variety of movements and manual labour. In some cases certain weighted clothing can be worn under normal clothing, to disguise its use to allow exercise in casual environments.
Abdominal exercises are a type of strength exercise that affect the abdominal muscles. Human abdominal consist of four muscles which are the rectus abdomens, internal oblique, external oblique, and transversus abdominis. When performing abdominal exercises it is important to understand the effects, functions, the types of exercises, and think about how to perform this exercise safely.
General fitness training works towards broad goals of overall health and well-being, rather than narrow goals of sport competition, larger muscles or concerns over appearance. A regular moderate workout regimen and healthy diet can improve general appearance markers of good health such as muscle tone, healthy skin, hair and nails, while preventing age or lifestyle-related reductions in health and the series of heart and organ failures that accompany inactivity and poor diet.
Sports nutrition is the study and practice of nutrition and diet with regards to improving anyone's athletic performance. Nutrition is an important part of many sports training regimens, being popular in strength sports and endurance sports. Sports nutrition focuses its studies on the type, as well as the quantity of fluids and food taken by an athlete. In addition, it deals with the consumption of nutrients such as vitamins, minerals, supplements and organic substances that include carbohydrates, proteins and fats.
Starvation response in animals is a set of adaptive biochemical and physiological changes, triggered by lack of food or extreme weight loss, in which the body seeks to conserve energy by reducing the amount of food energy it consumes.
Muscle hypertrophy or muscle building involves a hypertrophy or increase in size of skeletal muscle through a growth in size of its component cells. Two factors contribute to hypertrophy: sarcoplasmic hypertrophy, which focuses more on increased muscle glycogen storage; and myofibrillar hypertrophy, which focuses more on increased myofibril size. It is the primary focus of bodybuilding-related activities.
White adipose tissue or white fat is one of the two types of adipose tissue found in mammals. The other kind is brown adipose tissue. White adipose tissue is composed of monolocular adipocytes.
Acquired generalized lipodystrophy is a rare skin condition that appears during childhood or adolescence, characterized by fat loss affecting large areas of the body, particularly the face, arms, and legs. There are 4 types of lipodystrophy based on its onset and areas affected: acquired or inherited, and generalized or partial. Both acquired or inherited lipodystrophy present as loss of adipose tissues, in the absence of nutritional deprivation. The near-total loss of subcutaneous adipose tissue is termed generalized lipodystrophy while the selective loss of adipose tissues is denoted as partial lipodystrophy. Thus, as the name suggests, AGL is a near-total deficiency of adipose tissues in the body that is developed later in life. It is an extremely rare disease that only about 100 cases are reported worldwide. There are three main etiologies of AGL suspected: autoimmune, panniculitis-associated, or idiopathic. After its onset, the disease progresses over a few days, weeks, months, or even in years. Clinical presentations of AGL are similar to other lipodystrophies, including metabolic complications and hypoleptinemia. Treatments are also similar and mainly supportive for symptomatic alleviation. Although HIV- or drug-induced lipodystrophy are a type of acquired lipodystrophy, its origin is very specific and distinct hence is usually not discussed with AGL.
Lipotoxicity is a metabolic syndrome that results from the accumulation of lipid intermediates in non-adipose tissue, leading to cellular dysfunction and death. The tissues normally affected include the kidneys, liver, heart and skeletal muscle. Lipotoxicity is believed to have a role in heart failure, obesity, and diabetes, and is estimated to affect approximately 25% of the adult American population.
Obesity and walking describes how the locomotion of walking differs between an obese individual and a non-obese individual. The prevalence of obesity is a worldwide problem. In 2007–2008, prevalence rates for obesity among adult American men were approximately 32% and over 35% amongst adult American women. According to the Johns Hopkins Bloomberg School of Public Health, 66% of the American population is either overweight or obese and this number is predicted to increase to 75% by 2015. Obesity is linked to health problems such as decreased insulin sensitivity and diabetes, cardiovascular disease, cancer, sleep apnea, and joint pain such as osteoarthritis. It is thought that a major factor of obesity is that obese individuals are in a positive energy balance, meaning that they are consuming more calories than they are expending. Humans expend energy through their basal metabolic rate, the thermic effect of food, non-exercise activity thermogenesis (NEAT), and exercise. While many treatments for obesity are presented to the public, exercise in the form of walking is an easy, relatively safe activity. Walking may initially result in reduced weight, but adopting the habit over the long term may not result in additional weight loss.