Effect of spaceflight on the human body

Banana Nutrition Concerns?

Cardiovascular System
Dynamic Tension exercises are not merely isometrics, since they call for movement. These divide until air reaches microscopic alveoli, where the process of gas exchange takes place. This requires the careful placement of electrode catheters in a pulmonary artery and the right atrium via the jugular vein of an awake horse followed by anesthesia and then delivery of electrical shocks of increasing intensity through the catheters. A nice easy work out with push-ups, sit-ups, military presses, curls, squats and lunges will not take a long time and can actually be done at home. Human Senses - Immune System Alcohol Effects Alcohol thins the blood which distorts the shape of the inner ear creating a false signal. Once your head tilts past that point, your eyes stop trying to keep things horizontal, and gives up, untwisting themselves. Doberman Pinschers with DCM also commonly die suddenly due to ventricular tachycardia.

Cardiovascular System Physiology

Aging changes in the heart and blood vessels

This increased ability of the aerobic energy system to produce energy using both carbohydrates and fats is probably related to an increased mitochondrial activity in the trained muscles. As more ATP is produced aerobically, there is a lesser need for involvement of the anaerobic pathways and thus less lactic acid will be produced. Lactic acid can have an inhibiting effect on the release of fatty acids from fat depots because it blocks the action of epinephrine, a fat mobilizing hormone.

Therefore, the result is more fatty acids are delivered to the muscle for energy utilization. In addition, evidence suggests that the hormone-sensitive lipase enzymes of the fat cells become more sensitive to epinephrine and norepinephrine after aerobic training Lamb, Thus a smaller production of these two hormones will still be able to positively stimulate the release of fatty acids for utilization. The Effect of Exercise on Reducing Infection Regular exercisers claim that they have fewer infections and colds then their sedentary counterparts.

While some studies show that physically active people have fewer colds and infections, it may not just be the result of exercise. It has been hypothesized that exercise may boost the immune system, or that active people take better care of themselves, or there may be a natural buildup of antibodies as we age. Support for the boost in the immune system function seems to be growing.

Moderate exercise has shown increases of circulating levels of interleukin-1, which stimulates the immune system by increasing the activity of the lymphocytes, the primary cells involved in the immune response. Moderate aerobic exercise also increases the production of some of the interferons, a group of naturally occurring proteins with antiviral properties.

However, this increase only lasts for up to two hours after exercise and thus is suspect with regard to its potential long-term antiviral effect. It should be noted that regular, strenuous exercise has also been shown to have an opposite effect on the body's immure system. Persistent high intensity exercise may actually increase the likelihood of respiratory infection by suppressing some components of the immune system immediately after the exercise session. This adds more support for an exercise prescription directed towards regular, moderate levels of exercise participation.

Maintaining a higher bone mineral density throughout life may help to prevent many fractures associated with low bone density, which is a growing public health concern. The underlying mechanisms by which bone responds to physical activity are not well-known. Bone, like muscle will adapt to the imposed stresses, or lack of them, by forming more or less tissue. This process occurs via a remodeling cycle involving bone-forming osteoblasts and bone-reabsorbing osteoclasts.

When stress is applied to the bone with weight-bearing activities or with the muscles via resistance training, the osteoblastic activity exceeds the osteoclastic activity, which leads to a gain in bone tissue. If the stress decreases, i. Although swimming is considered a nonweight-bearing activity, the positive contributions to bone mineral density may occur through loads created from the muscular activity.

More research is needed in this area. It should be noted that the effect of exercise on bone mass is not an ongoing process.

A point will be reached at which, even with an increase of training, increased bone mass will be negligible. Currently there are several theories which try to explain how exercising the body can affect the mind. One theory states that physical training gives people a sense of mastery or control over self and their environment. This control becomes associated with a sense of well-being that enhances the self-concept, self-efficacy, reduces anxiety, and positively affects other personality variables Greist et al.

Morgan hypothesizes that physical exercise provides a distraction or diversion for anxiety provoking cognitions. A similar hypotheses is that exercise is a form of meditation which precipitates an altered state of consciousness that may relieve depression and anxiety Van Andel, Folkins and Sime hypothesize that fitness training enhances a person's ability to adapt and cope with the environment.

Increases in fitness reduces the excitation of emotion-provoking stimuli by slowing autonomic responses i. Regular physical exercise stimulates the central nervous system which increases the transport of oxygen to the brain as well as cerebral metabolic activity of various neurotransmitters including dopamine, serotonin, norepinephrine, and acetylcholine.

Endurance running has also been shown to produce immediate increases in beta endorphins in the blood after training. It is important to interject that the contents of our blood do not directly reflect what is happening in brain tissue. It is still not clear whether beta endorphin levels outside of the brain rise and fall in a parallel manner with those in the brain. At present, the hypothesis that exercise-produced endorphins result in mood alteration remains plausible, but not satisfactorily demonstrated in the literature.

Allen's "detoxification" theory is another credible explanation. With this theory, it is hypothesized that exercise "detoxifies," or gets rid of the stress-related hormones quickly.

This could be a result of the increased metabolism from exercise or possible unknown hormones involved in this complex occurrence. The efficacy of exercise to reduce stress and improve mental well-being is well-founded and supported even though the underlying mechanisms to these changes is speculative. Yet there is plenty of reason to be optimistic that this mystery will unfold. A great deal of interest exists in the research community involving this phenomenon which will surely lead to a better understanding, development and application of theories underlying the relationship between physical activity and mental health.

The Effect of Exercise on Cardiac Risk It is important to emphasize that only individuals with underlying heart disease are at risk of a cardiac event i. No evidence suggests that people with healthy cardiovascular systems are at risk of sudden cardiac death from exercise. It is the cardiovascular pathology, not the exercise, that establishes the likelihood of a cardiac event Franklin et al. The importance of the aerobic warm-up and cool-down cannot be minimized, as this is the time when cardiovascular events may occur.

For instance, one theory regarding the risk of a cardiac event upon abrupt cessation of exercise involves the relation between blood pressure and the hormones, epinephrine and norepinephrine.

During exercise, epinephrine and norepinephrine stimulate the heart to beat faster. When exercise stops abruptly, the blood pressure begins to drop rapidly, but the hormone response continues to stay up, causing the heart to continue its fast pumping. The venous blood return to the heart also slows creating an imbalance in the body's circulatory system the heart is rapidly pumping with an inadequate blood supply.

This anomaly may mediate an irregular heart response. This is why exercisers need to be continually reminded of the importance of a progressive aerobic cool-down to their workout. Bananas can be one perplexing food. We know that they are high in sugar- and that sugar is anything but good for us- but we also hear that they are full of important nutrients.

This is actually one of the questions I get asked most often, so allow me to explain more about the pros and cons of eating bananas. They can provide a quick source of energy before a workout and also vital post-workout nutrients that are needed to repair muscle and balance water retention. Additionally, bananas contain filling fiber too. All of these benefits within one calorie piece of fruit sounds like a good deal, but bananas can also be tricky for certain people and may not be the best fruit choice for everyone.

Because bananas contain a relatively high amount of sugar and carbohydrates, but practically no protein or healthy fats, they can quickly spike blood sugar levels. This is a problem for anyone who has a form of insulin resistance, including those who are pre-diabetic or who have diabetes. Therefore bananas make a great fruit choice for most people, but not all.

If you are someone who is otherwise healthy and relatively active, bananas are a smart and beneficial food choice to add to your diet.

However if you have sensitives to insulin, trouble managing blood sugar, and substantial weight to lose, you may want to go with other fruit and food options over bananas. Bananas are a great pick-me-up snack because they provide carbohydrate in the form of quick-releasing sugars which your body can use for energy.

After a workout, your body uses carbohydrates to refuel and repair muscle fibers that have been broken down. After exercising, banana nutrition contains sugar molecules that are able to reach muscle tissues fast right when they are needed most. This helps restore glucose reserves quickly, which is vital for giving your body the energy it needs to build muscle and strength.

Bananas are useful either before exercise or immediately after, providing your body with the sufficient carbs and nutrients that it needs. At just calories, bananas make a great pre or post workout snack choice, especially considering they are a whole food and contain no processed or artificial ingredients like many packaged snacks do.

Bananas are one of the richest sources of potassium in the world, with about mg of potassium per banana. Potassium is another nutrient that is crucial for those who are physically active, but also for everyone else too. Potassium acts as an electrolyte and promotes circulatory health, helps to manage blow flow and hydration levels within the body, and helps oxygen to reach your cells 1. Potassium is useful in preventing high blood pressure and decreases the risks for heart disease and strokes because it regulates circulation, sodium, and water retention within the body 2.

Potassium helps to lower high blood pressure because it counteracts the effect of sodium within the blood. Fortunately, studies have shown that the best way to benefit from potassium is to consume more of it naturally though whole food sources, especially fruits and vegetables 3. Potassium also assists in the prevention of muscle cramping following exercise and helps you to heal and build muscle. This makes it an important nutrient for anyone who is especially physically active or who is recovering from an injury.

The fiber in bananas helps to prevent constipation , bloating, and other unwanted digestive symptoms. Fiber helps to regulate restoration and maintenance of regular bowel functions because it binds to waste and toxins within the digestive tract, helping to pull them out of the body. Dietary fiber also importantly helps you to feel full for longer.

Studies have found that a diet high in dietary fiber is protective against heart disease, cardiac arrest, and stroke. Fiber helps to reduce inflammation as it removes waste and toxins from the body, keeping arteries clear from dangerous plague build-up 4 5.

Additionally, bananas are easy to digest and can help prevent cases of diarrhea. This is because of their starches and fiber which can help to bind waste within your digestive tract, while their potassium facilitates in balancing water retention in the gut and keeping you from becoming dehydrated. Healthy levels of serotonin work to lift your mood and prevent mood disorders including anxiety and depression. Banana nutrition also includes antioxidants that help with the release of dopamine within the brain, another mood enhancing hormone 7.

Regularly consuming bananas can help to increase your energy, prevent fatigue from over-exerting yourself, and to keep a positive mindset. Manganese is important for many functions within the body, including maintaining healthy skin, keeping the skeletal structure strong, maintaining proper brain function, and reducing free radical damage.

Some animal studies have shown that low levels of manganese contribute to poor bone health and possibly evn conditions like osteoporosis. Bananas are low in calories with only about calories for one medium size banana. This makes bananas a good choice for anyone who is watching their calorie intake in order to lose weight.

Because bananas contain high amounts of fiber and have a high water content, they can help to fill you up and keep you from snacking on other processed foods between meals. This makes bananas a great way to satisfy your sweet tooth with something completely unprocessed, without derailing your weight loss efforts too much. Another benefit of bananas? They are one of the least expensive varieties of fruit you can buy; even organic bananas are usually very affordable. I do however caution people to consume bananas in moderation if weight loss is your first health priority, since the sugar content of bananas can impact your blood glucose levels and potentially lead to food cravings or energy spikes and dips.

If you are going to have a banana as a snack, try combing with it a source of healthy fat or protein to slow down the release of its sugars into your blood stream.

Adding some almond butter, coconut, or protein powder to your banana snack can make it even more filling and impact your glucose levels less abruptly. As previously mentioned, even though they are packed with certain beneficial nutrients, bananas may not make the best food choice for everyone.

Those who have trouble keeping blood sugar levels at a healthy state or who are trying to lose weight may be better off leaving bananas behind or at least only consuming them in moderation in order to keep blood sugar at its safest levels Compared to other fruits- like berries, citrus, and kiwis- bananas are somewhat high in sugar and lower in fiber.

Fiber is crucial for helping to slow down the absorption of sugar into the bloodstream. These lower sugar fruits are considered to be lower on the glycemic index than bananas so they have a less dramatic impact on blood glucose.

How to improve circulation