Dr Dingle's Blog / exercise
Sleep is as important to the human body as food and water, but most of us still don’t get enough sleep. We obtain treatment for illness or injury – yet we generally fail to seek help when we aren’t getting enough sleep. The average length of sleep has declined from around 9 hours a hundred years ago to seven hours today. And the depth of sleep has also declined.
Sleep is complicated in the way that there are many different factors that influence the effectiveness of sleep. It’s not just duration that determines the effectiveness of sleep, factors such as quality, frame of mind and deepness all contribute to the maximum desired outcome and even our perception of how we sleep. Many factors can play a part in the quality and quantity of our sleep.
On average a healthy person will spend around one third of their life sleeping. Inadequate hours of good quality sleep leads to a disruption to vital biological processes resulting in a decrease in mental and physical health including impaired cognitive function and lower productivity and work performance due to a decrease in attention, judgment and responsible decision making.
Numerous studies have also shown that even a little bit of sleep deprivation decreases efficiency and increases risk of disease, including cardiovascular disease, diabetes and cancer. Some of the physical effects found from long term fatigue are heart disease, diabetes, high blood pressure, gastrointestinal disorders, depression eating disorders and weight gain. Sleep deprivation has also been shown to negatively affect endocrine (hormones) and metabolic functioning as well as nervous system balance. A recent meta-analysis which included 122,501 subjects found that insomnia determined an increased relative risk of 45% of developing or dying from cardiovascular disease during the follow-up.
Sleep debt has been found to lead to elevated evening cortisol levels and impaired glucose tolerance and is a risk factors for the development of insulin resistance and perhaps type 2 diabetes.
Obesity is another disorder linked with sleep with sleep deprivation. Many studies, including one spanning twenty years, have shown increasing weight gain with poor sleep. Shift workers for example are known to be a high-risk group for obesity.
While many factors can contribute to insomnia and poor sleep undoubtedly the most important one in the twenty first century is stress. Increasing research shows that there is an activation of the stress-response system and the degree of sleep disturbance experienced correlates with the level of stress-response activation and that insomniacs and others with poor sleep patterns experience more psychological stress.
Unfortunately, there can be a vicious cycle of stress poor sleep and more stress. If you are not getting enough sleep, you have to rely more and more on your alarm clock, and if you oversleep and wake up already fatigued. Thus, a person who is always feeling tired – even after a good night’s sleep – may have overworked adrenal glands.
Cortisol levels are highest in the morning and decrease gradually throughout the day. The body develops a routine, and cortisol is secreted at roughly the same amounts at a particularly time of day, depending on levels of stress. If an individual does not receive enough sleep they will produce more cortisol than they would on a normal routine day. Studies also show that stress and elevated levels of cortisol actually inhibit the ability to fall asleep, further exacerbating stress symptoms.
In another study although all subjects reported equivalent numbers of daily stressful events, people with insomnia found the impacts of these events to be more severe. Insomniacs also experienced major life events more intensely, were much more alert before bedtime, viewed their lives as more stressful, and used emotionally-based coping strategies to deal with stress more often than did the normal sleeper group. It appears that although normal sleepers and insomniacs experience similar types of stressful inputs in insomniacs the stress-response is more sensitive to these inputs and its activation leads to lack of sleep.
The effects of sleep deprivation can include fatigue, reduced productivity, slower reflexes and reactions, moodiness and a lack of energy, mimicking many of the characteristics of stress. The more hours we spend awake, the more sluggish our minds become, according to the findings. One night without sleep reduces our brains ability to take in new information by nearly 40 percent, due to a shutdown of brain regions during sleep deprivation. Impaired sleep function decreases the neuroplasticity in the central nervous system resulting in diminished cognitive function as impulse transmission are impaired. Sleep is the regenerative time for the Central nervous system and nerves, without which brain atrophy and weakened conduction can result.
Brains that are sleep deprived aren’t as efficient and have to work harder. Exactly want you don’t want. Studies show the brains of the sleep deprived desperately pumping energy into the prefrontal cortex, trying to overcome the effects of sleep deprivation.
Sleep plays an important role in consolidating memories. While we sleep, our brain orders, integrates and makes sense of things that have happened to us. Not only that, but we seem to consolidate our learning while we sleep. Without sleep the process is badly disrupted, meaning it’s difficult to lay down long-term memories and it’s harder to learn new skills. Sleep deprivation causes many of the powers of focus and attention to decline which partly explains the distracted feeling you get when tired. Sleep deprived people easily get stuck in thinking loops and as a result fall back on the brain’s automated systems, our habits.
Perhaps it is time we valued sleep more and turned off the TV and computer earlier so we can be healthier and smarter the next day. 3 extra steps you can try to reduce stress related poor sleep include;
Meditate a few minutes before you go to sleep;
Try a sleep supplement from your local health food store; and
Don’t eat late and go for a little walk after dinner.
The study shows the benefits of more fruit to prevent diabetes and reduce diabetic complications for diabetics. Unfortunately, fruit has been put in with all the foods where sugar is added just because it has sugar in it. People are being driven away from consuming more fruit and I have argued against poor advice given to diabetics for years. If it is no bad show me the evidence.
While sugar is a major culprit in diabetes it is not a sugar illness it is a mithochondrial dysfunction brought about by sugar and other poor diet (trans fats, artificial sweeteners etc), microbiome issues and lifestyle including stress, inactivity and loss of metabolic tissue and even toxins in the environment. The difference is that the sugar in fruit comes with a large array of essential nutrients including vitamins, minerals, antioxidants and anti-inflammatory ingredients, fibre, enzymes, water and prebiotics. All of these are potentially involved in repair of the mitochondria.
Of all the studies I have looked at they show that, even for diabetics, fruit is beneficial even when it comes to blood sugar levels. When fruit is consumed the sugar in it does not behave the same way that added sugar does. There are many potential reasons for this but we need to look beyond just basic concepts like if sugar is bad all foods that have sugar in them must be bad. This is naive and does not reflect the complexity of the human body.
This study was of 0.5 million adults in China over 7 years of follow-up. It found that among those without diabetes at baseline, higher fruit consumption was associated with significantly lower risk of developing diabetes with a clear dose–response relationship. That is the more fruit the lower the diabetes. In addition, among those who had diabetes at the beginning of the study, higher fruit consumption was associated with lower risks of all-cause mortality and micro vascular (small blood vessel) and macro vascular (large blood vessel) complications.
"In this large epidemiological study in Chinese adults, higher fresh fruit consumption was associated with significantly lower risk of diabetes and, among diabetic individuals, lower risks of death and development of major vascular complications."
In the new year, with all the mention of healthy foods it is also important to put the role of physical activity in perspective and perhaps make that one of our top goals for 2017. Up until 10,000 years ago, humans were still living a nomadic, hunter-gatherer lifestyle, scouting the landscape in the search for food, which placed a high level of physical stress on the body. Even going back just 200 years, humans were much more physically active than they are today, living a predominantly agrarian life, running farms and crop fields.
The genetic and physical make up of humans has not changed significantly since those days, but our levels of physical activity have. In addition, with each subsequent generation, levels of physical activity have reduced - the highest participation in physical activity occurs amongst school-aged children and adolescents, but this tends to decrease with age. A study of 1032 participants, found that after age 9, physical activity decreased by 38 minutes per year, while weekend physical activity decreased by 41 minutes per year. Additionally, at around 13.1 years in girls and 14.7 years of age in boys, the level of physical activity went below the recommended 60 minutes of physical activity per day 1.
In Australia, conservatively more than 8000 deaths occur annually due to lack of physical activity, costing not only lives and suffering, but also millions of dollars to the health care system. Increased physical activity has been associated with increased life expectancy, as well as reduced risk of heart disease, stroke, hypertension, obesity, diabetes, cognitive decline and Alzheimer’s disease 2,3 and much more. The single biggest killer in Australia today is cardiovascular disease (CVD) and an individual who undertakes regular physical activity, is half as likely as his sedentary counterpart to contract cardiovascular disease (CVD) 4,5,6.
A large number of studies have reported that physical activity not only reduces the risk of, but also protects against coronary heart disease 7,8,9. Additionally, in a cohort study of 743,498 men, aerobic fitness in late adolescence was a good predictor of a heart attack later in life. However, obese men with high aerobic fitness had a higher risk of heart attack than lean men with low aerobic fitness. Therefore, it is important to be physically active and maintain a healthy weight to keep the risk of heart attack at it's lowest 10.
High Blood pressure, or hypertension, is characterised as any blood pressure over 140/90, with the optimal being 120/80. Exercise resulting in weight loss, has been shown to have significant benefits in reducing blood pressure. Numerous large population-based studies 11,12,13 have demonstrated an inverse relationship between physical activity and blood pressure. In addition, interventional studies where individuals were trained to do more physical activity, demonstrated that increased exercise works to lower blood pressure 14,15. Furthermore, a randomized, controlled trial, found exercise training is effective in lowering blood pressure in overweight, sedentary patients with high-normal or mildly elevated blood pressure, and that weight loss is of added benefit when combined with aerobic training 16.
Physical activity has been shown to decrease mortality and increase life expectancy. In a study of 252,925 men and women, those doing moderate activity (at least 30 minutes on most days of the week) decreased mortality risk by 27%, whereas those who met recommendations for vigorous activity, at least 20 minutes, three times per week- not much if you really think about it, had a 32% reduction of mortality risk 17 a finding consistent with many other studies 18,19,20. And it is not too late to start now no matte how old you are. In a 4.9 year longitudinal study of 9,777 men, it was discovered that those who improved from unfit to fit, reduced their all-cause mortality risk by 44% and cardiovascular mortality by 52%, compared to those who remained unfit 21.
Inflammation and Triglycerides
Inflammation is the underlying condition in many chronic illnesses, including CVD and cancer. Physical activity decreases inflammation and additionally, those with higher cardio fitness levels, have lower circulating levels of inflammation markers such as of IL-6, CRP and fibrinogen 22. Physical activity and fitness are also associated with improved plasma lipid (fat) profiles, including the ratio of high-density lipoproteins (HDLs) to low-density lipoproteins (LDLs), and plasma triglycerides. Triglycerides decrease by 24%, while HDLs increase by about eight percent, in response to regular physical activity 23,24. Studies have also shown similarly favourable findings in diabetes 25.
Low levels of physical activity and cardio-respiratory fitness, are associated with the development of metabolic syndrome and type 2 diabetes. In one study, older men and women, who were in the lowest third of cardio-respiratory fitness, had a 10-fold higher risk of developing metabolic syndrome than those who were in the highest third. There was a strong inverse association between fitness and metabolic syndrome, as well as a significant relationship to all the components of metabolic syndrome 26.
Additionally, a low fitness level has been found to be an important risk factor for incidence of type 2 diabetes - men with the lowest 25% of fitness had a relative risk of diabetes that was four times higher compared to those in the highest 25% 27. It seems that both physical activity and fitness are separately and independently associated with metabolic risk profile 28 i.e., they are both contributing factors to reducing the risk of metabolic syndrome.
Incorporating more exercise to the day-to-day routine, is crucial for sufferers of type 2 diabetes. In type 2 diabetes, insulin is in short supply, or is difficult for the body to utilize – exercise, has been shown to improve the body's sensitivity to insulin. Not only does exercise help improve the diabetic condition, it can also help reduce the risk of developing type 2 diabetes altogether. A Harvard University study examining the exercise habits of more than 70,000 women, showed that a 40 minute walk every day reduced type 2 diabetes risk by 40%, and with a longer walk the risk could be decreased by an even larger percentage.
Exercise also helps to increase blood flow, which is important to help reduce the risk of neuropathy, a common neurological disorder associated with type 2 diabetes. In addition, studies have shown that a short-term reduction in daily physical activity, negatively affects insulin sensitivity.
One small step for diabetes. Just as important as the amount of exercise for diabetes is the timing. Much of the damage done in diabetes is done by the circulating sugar and or high insulin levels causing oxidation, inflammation and acidosis. Going for a walk 10 or so minutes after eating, particularly after a large dinner can have a direct and rapid impact on lowering blood sugar and subsequently the amount of insulin required to control the sugar. It is very important to bear in mind that this small change to a days routine can make a big difference in managing diabetes.
The immune system may be enhanced or depleted, depending on the intensity of physical activity 29 - both too little and too much exercise is proven to be detrimental to the immune system. For example, there is a high incidence of upper respiratory tract infections (URTI) in professional athletes (50-70% getting an infection in the 2 weeks following a marathon), which suggest that too much exercise can act as an immunosuppressant. Similarly, longitudinal studies have shown that moderate exercisers can overcome URTIs in half the time that an elite athlete does. Studies have also demonstrated similar findings with a decrease in mucosal (salivary etc) immunity with excessive exercise 30. Whilst excessive exercise may have a detrimental effect to the immune system, research has suggested that moderate levels of exercise can be beneficial to the immune system. Blood lymphocyte concentrations of a sedentary person are comparable to that of a high performance athlete, whereas the lymphocyte count is higher in a person who undertakes regular moderate exercise. Research suggests that regular, but not excessive exercise, improves the immune system 31,32.
Osteoarthritis (OA) is the second most common cause of disability in the developed countries and Rheumatoid Arthritis (RA), has also become a major health concern 33,34. Both are degenerative diseases of the joints, which can be improved with the implementation of moderate aerobic and weight bearing exercise. Research shows that short term gains of muscle strength, and a range of movement can increase the functionality of patients suffering from OA or RA. In addition, improved fitness levels have been shown reduce the risk of gout, another form of arthritis, in physically active men 35.
Different forms of activity have shown to have important impacts on our hormones and endocrine system. In the period prior to, during and after exercise, the endocrine system reacts in order for the body to function effectively and at optimum levels. Simultaneously, hormones governing the body's regulation, such as epinephrine and norepinephrine, are produced in greater quantities to assist the body in operating efficiently.
Additionally, physical activity has demonstrated positive effects on mental health, and has been shown to be more effective than drug therapy without any deadly side effects and works well alongside counselling therapy for depression and anxiety. It has been shown to improve individuals’ mood, reduce anxiety and stress, and increase self-esteem. Physical activity has been demonstrated to bring about positive structural brain changes and plasticity, as well as alter the production of neurotransmitters including Gamma-Aminobutyric acid (GABA). If you want to be smarter make sure you get enough exercise.
On the other side of the equation a number of medications can have a negative impact on the level of physical activity. For example, the most prescribed drug worldwide, statins, which are used to lower cholesterol, reduce the effectiveness of exercise. A recent study found the statin previously sold under the brand name "Zocor," hindered the positive effects of exercise for obese and overweight adults by 85%. The study also found that this statin, decreased the effectiveness of the mitochondria (power house) in the muscles.
It seems that statins block the ability of exercise to improve the fitness levels of the individual that takes them. Participants in the exercise-only group increased their cardio-respiratory fitness by an average of 10% compared to a 1.5% increase among participants also prescribed statins. Additionally, skeletal muscle mitochondrial content, the site where muscle cells turn oxygen into energy, decreased by 4.5 percent in the group taking statins while the exercise-only group had a 13 percent increase, a normal response following exercise training.
With the new year upon us it is time to get serious about our physical activity. There are just far too many benefits. It doesn’t have to be much just a little bit every day is enough to get you started on a better health journey.
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“Walking is man's best medicine.”- Hippocrates
Walking is probably the most underestimated and undervalued activity we do. We often take it for granted until we have some injury or can no longer walk, while it is probably the single most important activity that keeps us healthy, alive and adds to the quality of our lives. As well as the benefits to health walking has potentially important environmental and social implications. It is also the least likely activity that is going to cause injury as we are designed to walk. Fossil records show that we have been walking (bi-pedal) for around 4 million years. That is a lot of walking and as time has progressed we have become better at it.
Walking is the most common and preferred activity for people, for example in the US 54% of women and 41% of men cite walking as their most common activity during the past month 1 and it as the most frequently reported physical activity among high school students 2. While it might be the major activity we just don’t do enough of it. In England, for example, 29% of adults do less than 30 min of moderate physical activity per week and about 8% do not even walk continuously for 5 min over 4 weeks 3
Just as important however is the speed of walking. Walking at a pace of 5–8 km/h expends sufficient energy to be classified as moderate intensity and is an easy and accessible way of meeting physical activity recommendations. Studies have also shown the speed of walking is important - in a meta-analysis of five studies (14,692 participants total), people in the slowest quarter of walking speed, had significantly higher mortality rates than did those in the fastest quarter 4, that is the faster walkers live longer. A very good reason to up the pace a bit. An average walk (not a stroll) is about 5.0 kilometres per hour (km/h) up to 6.5 or 7 km/h for a brisk walk.
Walking offers many benefits to health, whether it be preventing disease, contributing to emotional and cognitive health, or helping to maintain independence later in life. Walking is the real “wonder drug” that we all need to be taking. And while the benefits are multiple and the behavior is simple most of us don’t do enough of it. In effect the benefits of walking can been seen to outstrip all the potential for pharmaceutical drugs on the market place and in many cases walking can be seen as an alternative to conventional drug therapy. The health benefits and resulting medical care savings of walking and physical activity are extremely large. Further, these benefits accrue regardless of age, weight, or existing health challenges. In a study of institutionalized elderly women aged over 70 walking 50-65% of the maximum heartbeat had the effect of decreasing blood pressure together with improvement in flexibility, left hand grip strength, sense of equilibrium, self-esteem, depression and life satisfaction 5. People only need to be active for at least 150 minutes a week and it can occur in short bouts, lasting at least 10 minutes or longer periods if you like. But the more you walk, the faster and the bigger the steps you take the longer you live. No other activity shows up with so many benefits as walking.
Systematic reviews and meta-analyses have shown walking to have various and multiple health benefits including positive effects on fitness, fatness, blood pressure control, weight loss, depression and other areas of mental health and stress, and cardiovascular disease risk prevention, pain management and spinal support as well as some cancers such as colorectal cancer. A systematic review of walking found statistically significant reductions in body fat, BMI and blood pressure and increases in breathing capacity 6. The review reported a reduction in blood pressure of around 3.72 mm Hg, around the same lowering from most of the pharmaceutical drugs on the market. The greatest benefit was reported in those involved in group walking 6. This reduction is comparable to earlier large studies of walking and resting blood pressure 7 which found a 2% reduction in blood pressure from walking. The importance of this difference becomes significant when you know that a 2 mm Hg reduction in blood pressure can reduce coronary heart disease risk by 6% and stroke and trans-ischaemic attacks (transient strokes) by 15%. 8. While other studies have reported a reduction of only 2 mm Hg in blood pressure could reduce stroke mortality by 10% and mortality from vascular causes in a middle-aged population by 7%.
Walking has also been associated with a reduced risk and even playing a role in reversing type 2 diabetes. A Harvard University study examining the exercise habits of more than 70,000 women, showed that a 40 minute walk every day reduced type 2 diabetes risk by 40%, and with a longer walk the risk could be decreased by an even larger percentage. Even adults with Diabetes, those who walked for 2 or more hours a week lowered their mortality rate from all causes by 39 per cent. However, the timing of walking also appears to be important. Walking after a meal reduces the blood sugar and lipid levels by increasing their absorption into the muscles. Walking after a meal the sugar and lipids are directed into the muscles not to be added as fat around the liver. When you walk you use more than 200 different muscles which create healthy molecular signals which positively alter the body’s biochemistry and metabolism. One of these is a particular muscle chemical, lipoprotein lipase (LPL), a protein enzyme has been studied in depth because this enzyme has a central role in several aspects of lipid (fat) metabolism. LPL controls plasma triglyceride (fat) breakdown (burning the fat into energy), shifting the cholesterol from LDL to HDL and other metabolic risk factors decrease when we stand or begin walking. The importance of producing enough LPL cannot be underestimated as people who produce less LPL have a five-fold increase in the risk for death and greater chronic heart disease. The production of LPL is therefore extremely beneficial to us.
Regular walking is beneficial for enhancing mental health, for example, reducing physical symptoms and anxiety associated with even major stress. In a study of Post Traumatic Stress (PTSD) symptoms, depression, anxiety and stress, sleep quality, in 76 participants age, 47 they found total PTSD symptoms, combined symptoms of depression, anxiety, and stress, and sleep behavior were significantly and negatively associated with total walking time and that increased PTSD symptoms were associated with lower levels of walking. 10. In a study of twenty healthy, elderly adults with a mean age 70, negative feeling scores such as tension-anxiety, anger-hostility, and confusion significantly improved after walking 11.
Depression is a common disorder worldwide widely recognized now to be an inflammatory condition and not one of a serotonin imbalance like the drug companies want you to think. Walking has been shown to alleviate depression. In a Meta-analyses using eight trials showed that walking has a statistically significant, large effect on symptoms of depression 12 and no negative side effects. In a study investigating the mood in 102 sedentary, ethnic minority women over a five-month period they found walking significant decreased depressive mood and an increase in walking over the course of the study was associated with change in vigor 13. One study of fifty breast cancer patients reported 12 weeks of moderate intensity walking mid-way through chemotherapy had positive effects on fatigue, self-esteem and mood. The study reported 80 % adherence rate to completing the 12-week intervention and recording weekly logs and reported the self-managed, home-based intervention was beneficial for improving psychosocial well-being 14
Walking has also been found to improve our brain development. Older adults, who walk frequently, have lower risk for cognitive decline in later life. In a study of 299 adults, aged 65 or older, greater levels of walking, predicted greater volumes of frontal, occipital, entorhinal, and hippocampal regions of the brain, 9 years later. Walking 72 blocks, was necessary to detect increased grey matter volume, but walking more than 72 blocks added additional brain volume. Additionally, greater grey matter volume with walking reduced the risk for cognitive impairment 2-fold. Greater amounts of walking were associated with greater grey matter volume, which is in turn associated with a reduced risk of cognitive impairment. These findings are in line with data that, aerobic activity induces a host of cellular cascades that could conceivably increase grey matter volume 15.
We now know that Alzheimer’s disease is a cardiovascular condition related to blood flow and nutrients reaching the brain. Epidemiological data support an inverse relationship between the amount of physical activity including walking undertaken and the risk of developing both Alzheimer’s and Parkinson’s disease 16,17. Beyond this preventive role, exercise may also slow down their progression 18,19. Several mechanisms have been suggested for explaining the benefits of physical activity and walking in the prevention of Alzheimer’s. Walking improves the efficiency of the capillary system and increases the oxygen supply to the brain, thus enhancing metabolic activity and oxygen intake in neurons, and increases neurotrophin levels and resistance to stress. Walking activates the release of neurotrophic (brain growth) factors and promotes the formation of new blood vessels, facilitating the generation of new neurons and synapses, which in turn improve memory and cognitive functions 20.
Research with Alzheimer's Disease subjects has shown that walking plus conversation has an even better preventive effect than walking alone 21, suggesting that the "socialization effect" of exercise is an important aspect. In another controlled exercise trial, the practice of walking combined with bright light exposure improved sleep among Alzheimer's Disease patients 22 suggesting that we should be doing more of our walking outside in the sun with our friends.
Other co-benefits of regular walking include improved academic and job performance and improved community cohesion. Creativity has a number of positive benefits. Studies have found gains in participants’ ideational fluency (creativity) after aerobic running or dancing 23, with similar results for aerobic walking, regardless of participants’ fitness history 24,25. Whether one is outdoors, or on a treadmill, walking improves the generation of novel yet appropriate ideas, and the effect even extends to when people sit down to do their creative work shortly after. A group of four separate experiments by the same research group showed walking boosts creative ideation in both real time, and shortly after each of the four experiment variations. In the first experiment it was shown that walking increased the creativity of 81% of participants. In the second experiment, an increase in creativity, was still seen when participants were seated after walking. Experiment 3, demonstrated that walking outside prompted the most novel and highly creative thinking, when compared to those sitting inside and out, and walking inside. Walking is believed to promote free flow of ideas, being a simple and robust solution to increasing both creativity and physical activity 25. Perhaps every workforce should add some walking time?
“All truly great thoughts are conceived by walking.”- Friedrich Nietzsche (1889)
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Exercises on television shows like “the biggest losers“ give a false impression of the role of exercise. Exercise, unless it is extreme in the case of the biggest losers who have cameras and personal trainers and doctors etc. plays a relatively lesser role in weight loss and may even backfire in people who over do it. That doesn’t mean you don’t do anything because being active is critical for many aspects of your overall health and wellbeing were just saying you don’t have to be a gym junkie to get to your optimal weight. A lot of evidence shows that aerobic exercises which are great for the heart are minimally effective for weight loss, although they have multiple other benefits including reducing your risk of all forms of chronic illness. The problem is that, in general terms, exercise does not burn tons of calories (unless we’re doing heroic amounts of it). It doesn’t usually take much additional eating to wipe out any calorie deficit induced through exercise. For example the energy burned while walking 30 minutes (170 calories) each day will only lose you around one kilogram after 50 days. In the study, 23 overweight and healthy men engaged in a 6-month programme of exercise 108 minutes of exercise a week changed the expression of about a third of the genes in the fat cells, including some that relate to the risk of type 2 diabetes and the development of obesity. As well as changes in waist circumference, waist-to-hip ratio, diastolic blood pressure (the lower of the two blood pressure readings), resting heart rate and levels of HDL-cholesterol. However, weight only declined by 1 kg on average and appeared to be no less fat for their efforts.
In a meta analysis of children’s weight loss, Physical activity interventions were not associated with reductions of BMI. However, there was an association between the interventions and reduction of blood pressure. In a study of overweight people expending either 300 or 600 calories a day exercising for 12 weeks twice the exercise did not translate into improved weight loss. Those doing 300 calories of exercise lost an average of 2.7 kg compared to 3.6 kg for the 600 calorie exercise group. Double the exercise lead to a 30% extra loss of weight. Of interest those exercising for about half an hour a day (300 calories) had a more positive attitude to exercise. Doing larger amounts of exercise are harder which is a barrier to maintaining the exercise.
On the positive side exercise is great for keeping weight off. The more you are active the less likely you are to put on excess weight. In a study of 25 639 men and women an increase in weight was associated with higher risk of being inactive 10 years later. Compared with stable weight, a gain in weight of more than 2 kg per year is associated with physical inactivity
Exercising for weight loss
But don’t stop exercising if you like exercising just yet because the level of exercise also has a large impact on your Resting Metabolic Rate and thermogenesis. There are certain things you can do to improve your weight through exercise. The first is to increase your muscle mass through anaerobic, muscle building exercise. The more muscle you have the higher your resting metabolic rate. That is the more you burn excess fuel while you are resting
You can also use exercise and physical activity to increase your thermogensis at critical times, in a sense tricking you body into burning calories before it is stored around your waist. Insulin is a major contributor to weight gain. The more insulin released with a carbohydrate dense meal the more weight you put on around the waste. However, increasing physical activity soon after a meal, even just standing up increases the cells requirements for the sugar without releasing extra insulin. Within seconds of any physical activity one of the non-insulin sugar pathways into the cells, the Glut 4 transporters are activated to remove sugar from the blood. This reduces blood glucose levels and improves insulin sensitivity (very good for diabetics). That is less insulin does more work. Regular exercise also increases the number of Glut 4 transporters. The more you exercise the more Glut 4 transporters your body will make. Any diabetic will tell you that as soon as they exercise their blood sugar levels goes down straight away. This means less to be stored as fat around the waist. In a study of thirteen obese-patients with type-2 diabetes post-dinner resistance exercise improved both postprandial glucose and glycation-end products, the damage caused by sugar. Post meal physical activity takes the sugar out of the blood before it can cause harm and build up around the waist. Associated with the increase in Glut 4 transporters is that exercise also increases the production of mitochondria which are the energy burning factories of the cells, and a lack of exercise causes numbers to deteriorate.
Exercise for your hunger genes
Like the different foods exercise can also alter how hungry you feel. In its natural environment your body is in perfect balance and everything feeds back on itself to constantly bring it back into balance. While being more active and exercising generally sends messages to eat more, to keep it all in balance you can also use exercises to suppress your appetite and trick the body. Exercise can suppress appetite, subsequent energy intake, and alter appetite-regulating hormones for a period of time post-exercise. Most people experience appetite suppression following an acute bout of exercise as exercise reduces your immediate feelings of hunger. In a study of 9 women who had fasted for some time before the experiment. They found that appetite ratings of the subjects in the exercise group fell for up to 2 hours after they had been placed on a treadmill for 30 minutes. Similar results have been found with different types of workouts and generally the exercise with greater metabolic and mechanical demand (weight-bearing exercise) showed greater immediate appetite suppression. So if you are reducing your calorie intake it is worth being active before a meal as well to reduce those immediate hunger pangs.
There is just no down side to physical activity unless you try to do too much too quickly like the biggest losers.
Standing up for weight loss
Sitting for any length of time may not be good for us, as more and more evidence shows that sedentary behaviours including sitting, watching television, using a computer, and driving a car are risk factors, independent of physical activity, for adverse chronic disease in adults such as obesity, diabetes, heart disease and much more. You can do a long run every night, but if you sit too long during the day you still increase your risk of these chronic conditions. In a study of 2,761 women and 2,103 men without clinically diagnosed diabetes, sitting time was detrimentally associated with waist circumference, BMI (body mass index), weight gain, blood pressure, fasting blood fats, HDL cholesterol, two-hour postload plasma glucose, and fasting insulin. A sure way to put on weight. In a meta-analysis using 48 studies, a consistent relationship of sedentary behaviour with mortality was found with weight gain from childhood. That is, the greater the sedentary time in childhood, the greater the weight gain.
It appears that any type of brief, yet frequent, muscular contraction throughout the day—such as standing or moving—may create healthy epigenetic signals which positively alter the body’s biochemistry and metabolism. One of these is a particular muscle chemicals, lipoprotein lipase (LPL), a protein enzyme has been studied in depth because this enzyme has a central role in several aspects of fat metabolism. Experimentally reducing movement by sitting had a much greater negative effect on LPL regulation than a positive effect of adding vigorous exercise training on top of the normal level of non exercise activity. In rat studies the amount of time spent sedentary influences how our bodies process fats given that leg muscles only produce the lipase lipoprotein (LPL) fat-processing molecule when they are being actively flexed, either standing or moving. What this shows is that by simply standing up more frequently you increase your muscle activity to reduce sugar and fats in the blood. To achieve even better effects you can stand up after a meal rather than sitting down and watching Television. In support of this one study reported that independent of total sedentary time and moderate-to-vigorous intensity activity time, increased breaks in sedentary time were beneficially associated with waist circumference, body mass index, triglycerides, and 2-hour plasma glucose. While in a study of 70 adults involving sitting for nine hours, regular activity breaks lowered plasma insulin levels and lowered plasma glucose when compared with prolonged sitting, even when compared with physical activity. While physical activity lowered plasma triglyceride more with regular activity breaks, activity breaks were more effective than continuous physical activity at decreasing negative blood sugar and insulin levels in healthy, normal-weight adults.
Overall, there is a compelling case for sitting reduction to be included in clinical preventive advice as a key component of “active living,” where adults and children are encouraged to “stand up, move more and sit less” across different settings and locations throughout the day. Just standing up every 20 or 30 minutes can have a remarkable health benefit reducing your risk of many chronic illnesses. How simple is that. The results of these studies suggest that, at a minimum, we need to be breaking up our sitting time every 20 to 30 minutes.
Next time you want to go for a workout, or maybe just want to lower your blood pressure maybe you should consider a block of dark chocolate. Dark chocolate is abundant in flavanols which have been reported to increase the bioavailability and bioactivity of nitric oxide (NO). Increasing NO bioavailability has often demonstrated reduced oxygen cost and performance enhancement during submaximal exercise.
In this study of 9 cyclists Dark chocolate increased an number of measures to show improved performance including established gas exchange threshold (GET) and a two-minute time-trial (TT) as well as V.O2max by 6% .
Of late dietary supplementation with sodium nitrate or nitrate rich beetroot juice has become increasingly popular and has consistently been shown to reduce oxygen demands during submaximal exercise and resting blood pressure (BP). Recent studies have shown similar vascular improvements in NO levels from consumption of dark chocolate (DC) and previous studies have shown benefits in improving and lowering blood pressure in both normal and hypertensive patients. One study also reported reduced blood pressure from consumption of dark chocolate in overweight participants, demonstrating DC may decrease cardiovascular risk and enhance the cardiovascular benefits of moderate intensity exercise in at-risk individuals.