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The_Bulldog:
Fat Burning Zone vs. Aerobic Zone Differences in Training

You’ve probably heard that there’s a fat-burning zone for cardio workouts, right?  In fact, some machines even indicate a specific heart rate target to burn the most fat.  But are they right?  Is that the best place to target?  What about improving aerobic capacity?  Since it’s important to train for aerobic fitness too, does that mean you need to train twice, once in each zone?

Well, researchers at University of St. Thomas in Minnesota took 36 runners and did some detailed analysis of heart rates and fat oxidation vs. VO2 max (maximal oxygen uptake, a measure of aerobic fitness).  Here’s what they found:

The best fat burning zone was at about 68% to 87% of maximal heart rate, while the best aerobic zone was between 59% and 76%.  Note the big overlap.  Translation:  you can simultaneously optimize fat burn and aerobic fitness by targeting between 68% and 76%.

If you dig deeper, there are two other points worth noting:  a) the difference in fat calories burned can differ by a factor of 2 or so; this means there really is a fat-burning zone, and b) there is a high variability from individual to individual so you can’t just assume these averages apply to everyone; you’ll need to do some testing on yourself to see which range is best.

This comes from Journal of Strength and Conditioning Research 23(7): p2090-2095 (2009).

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Skip The Leucine And Save Your Money

The University Of Texas released the findings of a study comparing the anabolic (muscle growth) effects of leucine added to a whey protein drink versus jus the whey protein drink.  The timing was following a high intensity lower body workout.  Turns out, there was no difference.  So if you are paying extra for protein powder enhanced with leucine, save your money and just buy good old whey protein.

Applied Physiology and Nutrition Metabolism, 34: 151-161, 2009.

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Exercise keeps dangerous visceral fat away a year after weight loss finds UAB study
Published: Thursday, October 29, 2009 - 11:00 in Health & Medicine

A study conducted by exercise physiologists in the University of Alabama at Birmingham (UAB) Department of Human Studies finds that as little as 80 minutes a week of aerobic or resistance training helps not only to prevent weight gain, but also to inhibit a regain of harmful visceral fat one year after weight loss. The study was published online Oct. 8 and will appear in a future print edition of the journal Obesity.

Unlike subcutaneous fat that lies just under the skin and is noticeable, visceral fat lies in the abdominal cavity under the abdominal muscle. Visceral fat is more dangerous than subcutaneous fat because it often surrounds vital organs. The more visceral fat one has, the greater is the chance of developing Type 2 diabetes and heart disease.

In the study, UAB exercise physiologist Gary Hunter, Ph.D., and his team randomly assigned 45 European-American and 52 African-American women to three groups: aerobic training, resistance training or no exercise. All of the participants were placed on an 800 calorie-a-day diet and lost an average 24 pounds. Researchers then measured total fat, abdominal subcutaneous fat and visceral fat for each participant.

Afterward, participants in the two exercise groups were asked to continue exercising 40 minutes twice a week for one year. After a year, the study's participants were divided into five groups: those who maintained aerobic exercise training, those who stopped aerobic training, those who maintained their resistance training, those who stopped resistance training and those who were never placed on an exercise regimen.

"What we found was that those who continued exercising, despite modest weight regains, regained zero percent visceral fat a year after they lost the weight," Hunter said. "But those who stopped exercising, and those who weren't put on any exercise regimen at all, averaged about a 33 percent increase in visceral fat.

"Because other studies have reported that much longer training durations of 60 minutes a day are necessary to prevent weight regain, it's not too surprising that weight regain was not totally prevented in this study," Hunter said. "It's encouraging, however, that this relatively small amount of exercise was sufficient to prevent visceral fat gain."

The study also found that exercise was equally effective for both races.

The_Bulldog:
Moderately Reduced Carbohydrate Diet Keeps People Feeling Full Longer


-A modest reduction in the amount of carbohydrates eaten, without calorie restriction and weight loss, appears to increase a sense of fullness, which may help people eat less, a preliminary study found. The results were presented at The Endocrine Society's 91st Annual Meeting in Washington, D.C.

"There has been great public interest in low-carbohydrate diets for weight loss, but they are difficult to maintain, in part because of the drastic reduction in carbohydrates," said coauthor Barbara Gower, PhD, a professor in the Department of Nutrition Sciences, University of Alabama at Birmingham.

In this study funded by the National Institutes of Health, Gower and her co-workers investigated whether a modest reduction in dietary carbohydrates, or "carbs," would improve feelings of fullness better than a carbohydrate level comparable to that of the typical U.S. diet.

In a standard American diet, according to Gower, 55 percent of daily calories consumed come from carbohydrates: sugars, starches and fiber. The control diet used in their study contained 55 percent of daily calories from carbohydrates, in contrast to their "moderate-carb diet" which was 43 percent of calories from carbohydrates. The moderate-carb diet had more fat than their control diet—39 percent versus 27 percent of calories—so that protein intake could be the same percentage. The researchers matched the protein intake of both diets studied (18 percent of calories) because protein may influence both satiety ("fullness") and insulin secretion.

The authors assigned the moderate-carb diet to 16 adults and the standard diet to 14 adults for a month. Subjects received enough calories to maintain their weight at what it was before the study. During the study they were weighed each weekday, and if a participant gained or lost weight, the amount of food was modified individually so weight could stay the same. After the subjects adjusted to their diet for 4 weeks, they ate a test meal, a breakfast that was specific to their diet.

When carbs are eaten and digested, they change into sugar. Before and after the meal, the researchers measured the subjects' levels of insulin and circulating glucose (nonfasting blood sugar) and asked them to rate their hunger or fullness. They evaluated insulin response to a meal and blood sugar levels, because lower insulin and stable blood sugar levels may contribute to increased feelings of fullness, Gower explained.

Their research showed that, even in the absence of weight loss, a modest reduction in dietary carbohydrates was sufficient to lower insulin and stabilize blood sugar after a meal. Ratings of fullness were higher in the group on the moderate-carb diet before eating breakfast and stayed higher for a longer time after the meal, compared with those eating the standard diet.

"Over the long run a sustained modest reduction in carbohydrate intake may help to reduce energy consumption and facilitate weight loss," Gower said.

Paula Chandler-Laney, PhD, of the University of Alabama at Birmingham presented the study results.

ScienceDaily (June 12, 2009)

The_Bulldog:
Exercise Therapy Best For Knee Pain, Study Finds



For patients with severe knee pain, supervised exercise therapy is more effective at reducing pain and improving function than usual care, finds a study published on bmj.com.

Patellofemoral pain syndrome is a condition in which pain occurs at the front of the knee during or after exercise and is a common reason to visit the doctor. Women are more likely to be affected than men, and symptoms usually start during adolescence when participation in sporting activities is high.

General advice is to rest during periods of pain and to avoid pain provoking activities. This "wait and see" approach is considered usual care.

A recent study reported only limited evidence for the effectiveness of exercise therapy with respect to pain reduction, while there is conflicting evidence with respect to functional improvement.

So researchers based in the Netherlands investigated the effectiveness of supervised exercise therapy compared with usual care in 131 patients aged between 14 and 40 years with patellofemoral pain syndrome.

A total of 131 participants were included in the study, 65 to a supervised exercise program (intervention group) and 66 to usual care (control group). Both groups received similar written information about the syndrome and similar instructions for home exercises, as well as advice to refrain from painful activities.

Patients rated their recovery, pain at rest, pain on activity, and function scores at the start of the study and again at three and 12 months.

After three months, the intervention group reported significantly less pain and better function than the control group. At 12 months, the intervention group continued to show better outcomes than the control group with regard to pain at rest and pain on activity, but not function.

A higher proportion of patients in the exercise group than in the control group reported recovery (42% v 35% at three months and 62% v 51% at 12 months), but these results were not significantly different between the two groups.

This study provides evidence that supervised exercise therapy for patellofemoral pain syndrome in general practice is more effective than usual care for pain at rest, pain on activity, and function at three and 12 months, say the authors. However, supervised exercise therapy had no effect on perceived recovery.

Further research is needed to understand how exercise therapy results in better outcome, they conclude.

ScienceDaily (Oct. 20, 2009)

The_Bulldog:
Breeding Better Broccoli: Research Points To Pumped Up Lutein Levels In Broccoli


Carotenoids -- fat-soluble plant compounds found in some vegetables -- are essential to the human diet and reportedly offer important health benefits to consumers. Plant carotenoids are the most important source of vitamin A in the human diet; the carotenoids lutein and zeaxanthin, found in corn and leafy greens vegetable such as kale, broccoli, and spinach, are widely considered to be valuable antioxidants capable of protecting humans from chronic diseases including age-related macular degeneration, cancer, and cardiovascular disease.

Vegetables in the cabbage family (such as kale, cauliflower, and broccoli) have long been known as especially good sources of dietary carotenoids. Recently, broccoli has emerged as the stand-out member of the species, providing more carotenoids to American consumers than any of its cabbage-family relatives. Yet, little has been understood about the carotenoid make-up of this popular green vegetable -- until now.

Mark W. Farnham of the U.S. Department of Agriculture, Agricultural Research Service, Charleston, South Carolina, and Dean A. Kopsell from the Plant Sciences Department, University of Tennessee, Knoxville, designed a research study aimed at finding out more about the carotenoid content of field-grown broccoli and determining the effects of genetics and the environment on carotenoid levels. The duo's research confirmed that broccoli heads contain abundant levels of lutein, an antioxidant commonly thought to provide nutritional support to eyes and skin. Other carotenoids like beta-carotene, violaxanthin, neoxanthin, and antheraxanthin were also found in broccoli heads, but lutein was clearly the most significant, accounting for about half of all carotenoids measured.

The researchers also discovered that when it comes to breeding broccoli, lutein levels were linked to the plants' genetics; the environment in which the vegetables were grown had little effect on carotenoid production.

The full study, published in a recent issue of HortScience, includes recommendations for vegetable breeders interested in producing vegetables that feature higher lutein levels. "Ultimately," reported Farnham and Kopsell, "this research indicates that breeding cultivars with increased levels of this particular carotenoid may be feasible."

ScienceDaily (Nov. 8, 2009)

The_Bulldog:
Cardiovascular Benefits Of Omega-3 Fatty Acids Reviewed

 Thousands of research studies have documented how the oils known as omega-3 fatty acids can benefit the cardiovascular system, particularly among people diagnosed with coronary artery disease. The incredible volume of research on this topic creates difficulty for many physicians and patients to stay current with findings and recommendations related to these oils. In the March issue of Mayo Clinic Proceedings, contributors briefly summarize current scientific data on omega-3 fatty acids and cardiovascular health, focusing on who benefits most from their protective effects, recommended guidelines for administration and dosing, and possible adverse effects associated with their use.

Two omega-3 fatty acids that have been associated with cardiovascular benefit, docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA), are found in fish oils. The best source for DHA and EPA are fatty coldwater fish such as herring, mackerel, salmon and tuna. Fish oil supplements or algae supplements also can provide omega-3 fatty acids.

Author James O'Keefe, M.D., a cardiologist from the Mid America Heart Institute in Kansas City, Mo., cites the results of several large trials that demonstrated the positive benefits associated with omega-3 fatty acids, either from oily fish or fish oil capsules.

"The most compelling evidence for the cardiovascular benefit provided by omega-3 fatty acids comes from three large controlled trials of 32,000 participants randomized to receive omega-3 fatty acid supplements containing DHA and EPA or to act as controls," explains Dr. O'Keefe. "These trials showed reductions in cardiovascular events of 19 percent to 45 percent. Overall, these findings suggest that intake of omega-3 fatty acids, whether from dietary sources or fish oil supplements, should be increased, especially in those with or at risk for coronary artery disease."

How much fish oil should people attempt to incorporate into their diets? According to Dr. O'Keefe, people with known coronary artery disease should consume about 1 gram per day, while people without disease should consume at least 500 milligrams (mg) per day.

"Patients with high triglyceride levels can benefit from treatment with 3 to 4 grams daily of DHA and EPA," says Dr. O'Keefe. "Research shows that this dosage lowers triglyceride levels by 20 to 50 percent."

About two meals of oily fish can provide 400 to 500 mg of DHA and EPA, so patients who need to consume higher levels of these fatty-acids may choose to use fish oil supplements to reach these targets.

Dr. O'Keefe also notes that research supports the effectiveness of combining the consumption of fish oil with the use of cholesterol-lowering medications called statins. Combination therapy with omega-3 fatty acids and a statin is a safe and effective way to improve lipid levels and cardiovascular health beyond the benefits provided by statin therapy alone. Blood DHA and EPA levels could one day be used to identify patients with deficient levels and to individualize therapeutic recommendations.

Dr. O'Keefe found little evidence of serious adverse effects associated with fish oil consumption. "In prospective placebo-controlled trials, no adverse effects were observed to occur at a frequency of more than 5 percent, and no difference in frequency was noted between the placebo and omega-3 fatty acid groups," he says.

The most commonly observed side effects include nausea, upset stomach and a "fishy burp." Taking the supplement at bedtime or with meals, keeping fish oil capsules in the freezer or using enteric-coated supplements may help reduce burping and upset stomach symptoms.

ScienceDaily (Mar. 12, 2008)

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