12

I will try to answer your question by using another perspective (risk factors for infertility). MALE Among the main causes of male infertility, "idiopathic" causes (ie not du to endocrine problems, genetic defects or sperm transport problems) represent 40%. In the last decades, increasing attention has been given to environmental factors. Here a brief ...


11

You have two main nervous systems when it comes to energy usage / conservation. Sympathetic Increased Heart Rate Dilation of bronchioles [increased intake / exhalation of air] Dilation of Pupils Vaso constriction in skin [tightening of blood vessels near skin] Vaso dilation in skeletal muscles [widening of blood vessels near muscles] Slowing of ...


8

Smoking in general is unhealthy. Smoking can result in emphysema, COPD, pulmonary hypertension and other ugly diseases [1,2,3]. After a workout your heart and respiration rates are higher than at basal levels. Although I do not have data to back me on this, based on scientific evidence on cardiopulmonary effects [4] after a workout and the hazards of ...


8

A decade ago, a study (1) reviewed the evidence regarding the effect of cycling on impotence (due for example to pudendal nerve entrapment) and the effect of repeated scrotal temperature on spermatogenesis. While sparse evidence suggested a possible link, the author concluded that those results needed to be replicated in larger studies. Some years later, ...


7

Well unfortunately, without a lot more detail on the changes you've made to your diet and how you go about your exercise, it is impossible to exactly pin-point where the problem is, but here are some facts and pointers to help you out. There are three main factors here: Hormone levels Diet changes How you exercise Hormone Levels Normally, training alone ...


7

The general consensus on the internet and among various physical trainers is that static stretching in 20-30 second segments is sufficient to increase range of motion (ROM) in a muscle. This is corroborated by two studies (Very similar in nature, conducted by the same people), where one study showed that there was no difference when time was increased from ...


7

Exercise does seem to have beneficial effects in treating and preventing many chronic diseases. As far as mechanism is concerned, we should probably narrow the scope: Question: What is the mechanism for the beneficial effects of exercise in people who have high blood pressure? It seems to be multifactorial, and independent of any impact on weight loss. ...


6

I could not find a report where this has been formally studied but it is highly likely that persons coming to plains after staying at high altitude will feel more energetic, for a few days at least. This is even used by many sports organizations. Quoting from "Human Biological Adaptability: Adapting to High Altitude": On returning to sea level after ...


6

As suggested by the answers in this question on fitness.se, the best time of the day is whatever works best for you. There is no magical time that will boost your metabolism more than other times, or anything like that. What most people are thinking of when they think of metabolism boosting is EPOC, or excess post-exercise oxygen consumption. This is ...


6

Provided that you are healthy, not suffering from a cold, disease state or other suppression of the immune system, moderate exercise during fasting periods should not impact your health. For submaximal efforts, you may notice earlier fatigue, and there will be definite performance impacts the closer you get to maximal efforts. Caveat: You are still ...


6

TL; DR: No, they won't impact growth if practiced within reason, and there is no damage to growth plates from injury. The medical community and the public in general seems to regard strength training as a general voodoo practice that will "hurt you". Fortunately, this has been getting debunked soundly for over a decade now. Despite earlier concerns ...


6

There really aren't any known harmful effects for an otherwise healthy person to eat directly after an exercise session. You may not have as much appetite, as the body will somewhat shut down the digestive system and redirect blood and other resources to more needed places in the body, but it is not actively harmful. In actuality, there are quite a few ...


6

If the runner can't drink then dehydration will be the first thing that takes him out. Water is the one essential thing he's going to lose rapidly through sweat, urine and respiration, and as he loses it he's going to lose electrolytes along with it. The end result will be disabling muscle cramps, weakness, and exhaustion. If he somehow continues on ...


5

The short answer is no, your metabolism isn't really driven by your heart rate. The basic definition of metabolism is that it is the process by which your body converts the food and liquid that you consume into energy to fuel the body. This can be generally divided into two components, catabolism, which is the breaking down of ingested items into energy, ...


5

Thank you for the very interesting question regarding the prostate. Let me first briefly explain a few historical confusions regarding the nomenclature of prostatic disorders with particular attention to your ‘congestive prostatitis’, which may be called an almost extinct creature! Classifications of Prostatic Disorders Meares and Stamey (1968) suggested a ...


5

It takes energy (and blood) to digest the food. So when you eat shortly before exercising, you need the energy at two places (digestion and muscles) and the muscles win. This does not mean it is bad to eat before (or during) exercise. Some exercises (like running a marathon) requires you to replenish the energy (and the food) but you can't eat anything. You ...


5

The simple answer is "metabolic lactic acidosis". According to Wikipedia, the duration of exercise and intensity (aerobic vs anaerobic) and prior food or drink consumption are the main factors contributing to this effect. Actually, the Wiki articles doesn't quite say that (?). Prior food/drink would determine the glucose and glycogen - the stored form ...


5

Most blood donors are a bit weakened from giving blood, despite feeling often great. The amount of blood removed from circulation reduces your possible performance level and you might tire more easily as the reduced volume of blood also means a reduction in oxygene availability. This small measurable level of performance reduction can reach up to three ...


5

It is not a fast heart rate but the underlying mechanisms that can affect health. The mechanisms involved in exercise can be beneficial and those in anxiety harmful. EXERCISE Physiological responses and long-term adaptations to exercise (CDC.gov): ...the cardiovascular response to exercise is directly proportional to the skeletal muscle oxygen demands ...


5

Yes, or at least, that's what this article in a reputable medical journal says and there is no reason to be more skeptical of it than the normal skepticism that any isolated article deserves. The 10 year IRR they find is 0.04 (95% CI 0.01-0.36), after adjusting for age and BMI, which is a pretty strong effect. The article is not claiming this is the best or ...


4

Evidence for the benefits of yoga is vast and easily accessible online. It is great to see question like this which focus on the comparison of yoga to other exercises. There is quite limited amount of studies which investigate the benefits of yoga over another type of exercise. When kids were examined yoga did not show benefits over traditional exercises ...


4

Currently, there is no definitive way to predict maximum heart rate for a single individual. There are formulae that can give an approximation, but about the only way to get a good estimate on a personal level is to do a maximal treadmill test with monitoring. As far as the 220-age, that is a bad myth, and wasn't based on a study, but simple observation of ...


4

Dizziness or giddiness during exercise is classically caused by obstruction to the outflow of the heart i.e. aortic stenosis (see MedlinePlus). This condition is most commonly seen in either young persons due to bicuspid aortic valve or in elderly with sclerotic aortic valves. In developing countries, it may occur due to rheumatic heart disease also. When ...


4

I wasn't able to find a study that looked at both meditation and exercise - besides ones about yoga - but I was able to find many that looked at each separately and seemed to indicate that combining the two is simple and effective. Exercise One of the best sources was a thesis by Nikelle Holbrook Hunsaker entitled "The Benefits of Exercise During Pregnancy"...


4

There seems to be a misconception at the driving part of the question. Exercise has more effects (on the brain) than just stimulating a few synapses. That is indeed a vague and vastly incomplete conception. Since brain chemistry is by far not completely understood it is also quite premature to believe we would be able to define some kind of "optimal" ...


4

As far as I know, there are no foods that burn fat in any significant amount (Mayo Clinic). To burn fat, a food would need to have "negative calories," which means less calories than the calories needed to digest that food. Theoretically this is possible, for example, water has zero calories and the process of water drinking and absorption requires some ...


4

I'm a physical therapist (PT) - considering we specialize in the application of movement and exercise. Consistency NOT time of day is the key to any exercise regimen. A walk in the park at 6AM or 2PM would have the same effects on "health". Ask him explain to explain the reasoning behind this - and - if he'd send or write down the the name of the research ...


4

Apart from the mental benefits of meditation, there is some evidence for organic/physical benefits as well. Dean Ornish, the well known cardiologist who helped former U.S. President Clinton with his diet - and the creator of the only FDA approved prescribed and reimbursed diet for cardiac disease, also has done studies on meditation and health. He found ...


4

The approach you describe most likely will not work, and could be detrimental to your training. The main benefit of training at altitude is that the body will adapt to the lower concentration of oxygen by stimulating the production of erythropoietin which in turn causes the body to produce more red blood cells. What you are describing is a very limited ...


3

The only way to tell if you are going to grow taller or not is to have an x-ray done of the epiphyseal plates. These are segments at each end of the long bones in your body where bone growth (and thus height increase) occur. They are cartilaginous plates that gradually increase the length of the bone by laying down new matrix. When they are fully closed and ...


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