Protein: A harmful or beneficial nutrient for bone
High protein intakes are considered essential to support the demands of training, and as such, athletes are recommended to consume more protein (between 1.2 and 1.6 g/kg/day, with up to 2.2 g/kg/day considered useful in some situations) than the general population (currently 0.8 g/kg/day). At the same time, there is a long held belief that higher protein intakes may actually have a negative influence on bone health. This is based on the “acid-ash hypothesis”, which suggests that animal proteins are acidic, and so can disrupt body pH. A balanced pH is essential for function of all body cells, and so the body will counterbalance an acidic state by increasing the availability of alkaline minerals, so normalising pH. The problem is, that most of the bodies alkaline minerals (e.g.,calcium) are stored within the bone. A chronic need to normalise pH in response to habitually high protein intakes, can, in the long term, result in bone mineral loss and weakening. Supporting this hypothesis is evidence that diets with a high potential renal acid load (PRAL), namely those high in animal proteins, are associated with a greater loss of calcium in the urine. This may be associated with lower bone mineral density, and an increased rate of bone loss.
The acid-ash hypothesis does have some possible merit, but it also describes just one of the pathways through which high protein intakes may theoretically influence bone, and is by no means the full story. For a start, the acid-ash hypothesis assumes that the calcium lost in the urine when protein intakes are high, comes from the bone. It seems, however, that higher protein intakes actually increase the amount of calcium that is absorbed from foods, and the increased calcium found in the urine when protein intake is high comes from this increase in calcium availability, and not from the bone, as was originally assumed.
Another important point, is that calculations of dietary acid load, are not only influenced by a high intake of acidic foods, but also by a low intake of alkaline foods. Most alkaline foods (e.g.,fruits and vegetables) are also rich in a wide range of micro- and phyto-nutrients that are essential to bone health. It is possible, therefore, that the poorer bone outcomes reported in individuals who consumed an acidic diet, were not actually due to high protein, but to a shortage of nutrient rich fruits and vegetables.
More importantly, evidence exists to show that not only is protein not harmful to bone, it can actually be beneficial. Bone tissue is made up of ~50% protein, which makes it essential that athletes consume sufficient protein to support the increased rate of bone turnover caused by athletic training. Additionally, protein ingestion is known to increase the production of a number of hormones and growth factors, such as IGF-1, which are also involved in the formation of bone. Perhaps most importantly, the physical loads caused by exercise training are recognised as the main determinant of bone. Athletes in high-impact sports are frequently reported to have stronger bones that non-athletes. These loads come from a combination of both gravitational and muscular forces. It follows, therefore, that if higher protein intake positively impacts muscle mass function, and the capacity to undertake exercise training, it should also positively influence bone.
Considering all of these factors, it seems paradoxical to believe that higher protein intakes could really harm bone. Ultimately, the only way to determine the net influence of protein intake on bone, is to examine original studies that investigate this. A large number of these types of studies have been conducted, and the results have subsequently been statistically combined in high-quality meta-analyses [5]. Considering all available evidence, the answer is clear: Provided calcium intake is adequate, there is no evidence to indicate a negative influence of protein on bone, and instead a positive, albeit small, effect on bone mineral density and fracture risk has been identified. And so, the consensus is that protein is an essential nutrient, not only for muscle, but also for bone.
Green Tea and Caffeine
Next to water, tea is the most widely consumed beverage in the world. Black, green, and oolong tea are all derived from the Camellia sinensis plant, which contains a class of polyphenols known as catechins. Catechins, particularly those found in green tea, have been shown to exert positive effects on energy expenditure (i.e., thermogenesis) and fat oxidation, and, therefore, consumption of green tea or green tea extracts may be beneficial for weight loss. The process by which green tea is produced (heat treatment shortly after harvest) results in less oxidation and, as a result, preserves the highest concentration of catechins, which include epigallocatechin gallate (EGCG), epigallocatechin, and epicatechin gallate. Green tea also contains caffeine; therefore, the two active ingredients in green tea believed to potentially induce weight loss are caffeine and catechins, particularly EGCG.
consuming two servings of green tea containing 500–900 mg of catechins and moderate amounts of caffeine (<200 mg) for 3 months results in positive effects on body composition and reduces intra-abdominal fat in moderately overweight Chinese subjects.
Two recent meta-analyses also suggest that the catechins and caffeine in green tea result in small, but positive effects on body composition and BMI.
Hursel et al. conducted a systematic review and meta-analysis of long- term studies (≥12 weeks) that examined the effect of EGCG on weight loss and weight maintenance and included potential moderators such as regular caffeine intake and ethnicity to determine if those factors influence the effect of EGCG + caffeine on body weight. Eleven of forty-nine studies identified met the inclusion criteria for the meta-analysis. The results showed a moderate, but significant positive effect of catechins on both weight loss and weight maintenance. It was estimated that individuals in the treatment groups lost 1.31 kg more weight (~0.6 lb) compared to the CTRL groups. When the effects of habitual caffeine use and ethnicity were taken into account, the results showed that individuals who consumed caffeine in quantities >300 mg experienced less of an effect on weight loss (−0.27 kg) compared to low caffeine users (−1.61 kg).
Based upon the findings, the authors suggested that a catechin/caffeine mixture had positive effects on weight loss and that ethnicity and habitual caffeine use may moderate their effects. In a related study, Phlung et al. performed a systematic review and meta-analysis to determine the effect of catechins with or without caffeine on anthropometric variables including BMI, body weight, waist circumference, and waist-to hip ratio. Of 341 citations retrieved through their search strategy, 15 trials met the inclusion criteria and were included in the meta-analysis. The results showed that catechins + caffeine decreased BMI, body weight, and waist circumference, but had no effect on waist-to-hip ratio compared to caffeine alone. In addition, catechin + caffeine ingestion resulted in a significant decrease in body weight compared with a caffeine-free CTRL.
However, there was no effect of catechins alone on any parameter when compared to caffeine-free CTRL, suggesting that catechin ingestion alone is ineffective for weight loss. Although these studies indicate that catechins work synergistically with caffeine to elicit significant reductions in body weight, BMI, and waist circumference, the magnitude of the changes is modest at best and is not clinically relevant.
There do not appear to be any adverse side effects associated with green tea consumption, and, although it has modest effects on weight loss, there is evidence that green tea has antioxidant components that benefit health and has been shown to improve cholesterol profiles, decrease platelet aggregation, and lower blood pressure.
Caffeine
Caffeine is an active ingredient in coffee, which is another one of the most common beverages consumed worldwide, but caffeine is also found in many other foods and beverages including dark chocolate, soda, and sports and energy drinks. Caffeine has been widely studied for its potential thermogenic effects and has been shown to increase REE and reduce energy intake; however, these acute effects have not resulted in meaningful long-term weight loss. Caffeine is usually studied in combination with other thermogenic ingredients for their effects on weight loss versus its effects alone; however, one 12-year longitudinal study showed that men and women who increased their caffeine consumption (143–213 mg) experienced slightly smaller weight gain (2.79–3.22 kg) compared to individuals who decreased their caffeine intake (3.87–4.28 kg) over the 12-year period. A lack of sensitivity to caffeine as a result of increased tolerance may explain, in part, why it is ineffective for weight loss over time.
Health Dangers of Anabolic Steroids
•Liver disease
•High blood pressure
•Increased LDL cholesterol
•Decreased HDL cholesterol
•Fluid retention
•Suppressed immunity
•Decreased testosterone
•Testicular atrophy
•Acne
•Gynecomastia
•Masculinization in women
•Muscle spasms
•Headache
•Nervous tension
•Nausea
•Rash
•Irritability
•Mood swings
•Heightened or suppressed sex drive
•Aggressiveness
•Lowered sperm count
•Drug dependence
Vitamin K (vital for building healthy bones)
The primary function of vitamin K is to assist in the process of normal blood clotting. It is also required for the formation of other kinds of body protein found in the blood, bone, and kidneys. However, research has revealed another side to vitamin K that most people were not aware of: It is vital for building healthy bones, which is why a number of calcium supplements are now being formulated with vitamin K. With a shortfall of vitamin K, bone can become weakened because of insufficient levels of osteocalcin, a protein involved in bone hardening. In one study with female athletes, 10 milligrams daily of vitamin K decreased the process of bone breakdown and increased bone formation. These improvements were measured by looking at the amount of osteocalcin (an indicator of bone formation), as well as at by-products of bone breakdown in the bloodstream and urine. A vitamin K deficiency is extremely rare, and there’s usually no need for supplementation unless recommended by your physician. The best food sources are dairy products, meats, eggs, cereals, fruits, and vegetables.
Energy balance
Energy balance refers to the balance between energy expenditure and energy intake. It can be measured on a day-to-day basis, but it probably makes more sense to measure it over a period of several days or weeks. When energy intake exceeds energy expenditure, the energy balance is positive and weight gain will occur. When energy intake is below energy expenditure, the energy balance is negative and weight loss will result. Generally, athletes are good at maintaining body weight and thus are in energy balance most of the time. Over the longterm, energy balance is maintained in weight-stable individuals even though this balance may be either positive or negative on a day-to-day basis. People who want to lose weight should increase energy expenditure relative to energy intake. In many activities in which body composition or body weight is believed to be important (gymnastics, dancing, bodybuilding, and weight category sports such as judo and boxing), participants often try to maintain a negative energy balance to lose weight. Thus, the energy intakes in these activities can be very low. At the other extreme are endurance sports such as triathlon, cycling, cross-country skiing, and ultra-endurance running, which require extremely high energy expenditures and energy intakes. In these sports, maintaining energy balance on a day-to-day basis is crucial for performance.
How Does Alcohol Affect Exercise Performance?
How Does Alcohol Affect Exercise Performance? Because alcohol depresses the central nervous system, it impairs balance and coordination and decreases exercise performance. Strength and power, muscle endurance, and aerobic endurance are all zapped with alcohol use. Alcohol also dehydrates the body considerably. To be a little more specific, if you knock down a few alcoholic beverages after a strength-training workout, you’re likely to increase damage to your muscles, experience greater muscle soreness, and diminish strength and power. Your muscleglycogen and tissue-rebuilding recovery from exercise will absolutely be diminished, and you certainly won’t fully rehydrate. These effects have been observed in research. As for endurance athletes, a study of trained cyclists given a small amount of alcohol after 60 minutes of cycling showed a significant decrease in average cycling power output, oxygen consumption, carbon dioxide production, and glucose oxidation.
Their heart rates increased, and they felt more fatigued and less energetic when they consumed alcohol. So basically, drinking alcohol has a negative effect on endurance performance. Also, alcohol use increases the risks of sport injuries. The bottom line: Alcohol will clearly put your training on the skids. It has no place during tournament play, when training occurs the day after a game, or when several games or events are played weekly. Although celebrating with alcohol may appear to be fun, it puts you and your teammates at risk.Women and Alcohol Women’s drinking patterns are different from men’s—especially when it comes to how much and how often they drink. Women’s bodies also react differently to alcohol than men’s bodies do. That means women who drink beyond moderate levels face a variety of health risks from alcohol.
Some specific reasons for this increased risk follow:
• Women typically start to have alcohol-related problems at lower drinking levels than men.
• Women typically weigh less than men.
• Pound for pound, women have less water in their bodies than men do, and alcohol resides predominantly in body water.
These health risks can include the following:
• Liver damage.
Women who drink are more likely to develop liver inflammation than men.
• Heart disease. Women are more susceptible to alcohol-related heart disease than men.
• Breast cancer. Women who have about one drink per day also have an increased chance of developing breast cancer compared to women who do not drink at all.
• Pregnancy. Any drinking during pregnancy is risky. Heavy drinking can put a fetus at increased risk for learning, behavioral, and other problems.
Vitamin D
Contrary to what most people believe, vitamin D is not a vitamin but a steroid hormone. It is produced in various parts of the body but exerts its influence elsewhere in the body—which is what hormones do. Your body can manufacture vitamin D on its own when your skin is exposed to sunlight. Just 15 minutes a day with your legs and face exposed to the sun without sunscreen several days a week usually supplies sufficient amounts of vitamin D. If you can’t get out in the sun, live in northern climates where there is not too much sunlight, or frequently wear sunscreen, you may need to take supplements. The form of vitamin D manufactured by the liver and measured in the bloodstream is called calcidiol, or 25 hydroxyvitamin D-2. The activated vitamin D steroid hormone is processed by the kidneys and is known as calcitriol, or 25 hydroxyvitamin D-3. Calcitriol circulates as a hormone in your body regulating the amounts of calcium and phosphate in your bloodstream and maintaining the health of your bones.
As a steroid hormone, vitamin D regulates more than 1,000 vitamin D–responsive human genes and may influence athletic performance, particularly if you are deficient in this nutrient. Numerous studies over many decades have revealed that physical and athletic performance peaks when 25 hydroxyvitamin D-2 levels peak in the summertime and declines as the steroid hormone declines in the body in the wintertime. Athletes tend to have low vitamin D levels in winter, according to a number of studies. Several studies also document low vitamin D levels in athletes that participate in indoor sports. If you’re an older athlete, make sure you get enough vitamin D from food and supplements, because elderly people are typically deficient in this nutrient. Supplements with vitamin D have been shown in numerous studies to boost performance in both younger and older adults with low blood levels of vitamin D.
Studies show that vitamin D reduces the risk for sport-related conditions such as stress fractures, total body inflammation, infections, and muscular function. Thus, raising your levels of vitamin D can reduce inflammation, pain, muscle weakness, and muscle-loss myopathy, while increasing muscle protein synthesis, ATP concentration, strength, jump height, jump velocity, jump power, exercise capacity, and physical performance. Vitamin D levels above 40 nanograms per milliliter of blood are required for fracture prevention, including stress fractures. Optimal musculoskeletal benefits occur when vitamin D is higher than 30 nanograms per milliliter of blood but not higher than 50 nanograms per milliliter.
In 2015, medical researchers went to the NFL and collected blood to study the vitamin D levels of 214 athletes among the athletes in attendance. Interestingly, inadequate vitamin D was present in 59 percent of the athletes, including 10 percent with deficient levels. Lower extremity muscle strain or core muscle injury was present in 50 percent of athletes, which was significantly associated with lower vitamin D levels. Athletes who had suffered numerous injuries also showed significantly lower vitamin D levels as compared with uninjured athletes. Even though football players practice outside during the heat of the day in the sunny summer months, they are typically somewhat covered up, blocking the sun’s rays from reaching their skin and raising levels of vitamin D.
There is also a connection between vitamin D and weight management. Vitamin D helps your body better absorb calcium, which has a fat-burning effect. So for calcium to assist in fat burning, your body requires sufficient vitamin D. On the other hand, if the calcium levels in your body are low, a hormone called parathyroid hormone (PTH) and vitamin D increase in response to the shortage and trick your body into thinking it is starving. Consequently, you may pack away more calories in the form of fat and put on extra weight when this imbalance occurs.
Eight Reasons to Pump Up Your Vitamin D
1. Supports bone health
2. Bolsters immunity
3. Boosts mood when taken with the omega-3 fatty acid DHA
4. Assists in neuromuscular control
5. Helps regulate body weight
6. Helps prevent aging-related inflammation
7. Lengthens telomeres (a factor in longevity)
8. Decreases the risk of many chronic and degenerative diseases
Drinking more water can actually help you stay lean
Drinking more water can actually help you stay lean. Your kidneys depend on water to do their job of filtering waste products from the body. In a water shortage, the kidneys need backup, so they turn to the liver for help. One of the liver’s many functions is mobilizing stored fat for energy. By taking on extra assignments from the kidneys, the liver can’t do its fat-burning job as well. Fat loss is compromised as a result. Researchers from Basel, Switzerland, investigated the role that cellular hydration plays in fat-burning and protein synthesis by looking at well-hydrated versus poorly hydrated cells. They found that under conditions of hypo-osmolality—which is essentially hyperhydration (lots of hydration in cells)—the subjects burned more fat because their bodies tapped into fat, rather than carbohydrate, for fuel. They also found that dehydration prevents adequate protein synthesis. If gaining muscle is your goal, you should care about the hydration state of your muscle cells (also called cell volumization). In a well-hydrated muscle cell, protein synthesis is stimulated and protein breakdown is decreased. On the other hand, dehydration of muscle cells promotes protein breakdown and inhibits protein synthesis. Cell volumization has also been shown to influence genetic expression (the process by which a gene carries out DNA instructions), enzyme and hormone activity, and metabolism. Bottom line: When you guzzle down that bottle of water, you’re potentially boosting not only fat burning but also the maintenance of normal cell volume levels that are important for muscle protein levels. In addition, water can help take the edge off hunger so that you eat less, and it has no calories. If you are on a high-protein diet, water is required to detoxify ammonia, a by-product of protein energy metabolism. And, as you burn off stored fatty acids as energy, you release any fat-soluble toxins that have been benignly stored in your fat cells. The more fluid you drink, the more you dilute the toxins in your bloodstream and the more rapidly they exit the body.
Diet induced thermogenesis
Diet induced thermogenesis ,or the thermic effect of food(TEF),is the increase in energy expenditure above RMR that occurs for several hours after ingestion of a meal. Diet Induced Thermogenesis is the result of digestion, absorption, metabolization, and storage of food and normally represents about 10% of total daily energy expenditure. The magnitude of Diet Induced Thermogenesis depends on several factors, including the energy content of the food and the size and composition of the meal. Diet Induced Thermogenesis also depends on the metabolic fate of the ingested substrate.
The cost of storing fat in adipose tissue is approximately 3% of the energy of the ingested meal, whereas if carbohydrate is stored as glycogen, about 7% of the energy is lost. The energy cost for the synthesis and breakdown of protein is approximately 24% of the available energy.
Energy expenditure can be increased up to 8 hours.The sympathetic nervous system seems to play an important role in Diet Induced Thermogenesis. When the effects of the sympathetic nervous system are reduced by administering aft adrenergic blocker (e.g.,propranolol), Diet Induced Thermogenesis is also reduced. With increasing age there is as mall decline in Diet Induced Thermogenesis. This might be associated with a decrease in insulin sensitivity.
