The top-cited sports science journals reveal the most influential trends, findings, and facts about fitness.

Every year, data and news service Thomson Reuters compiles an index of the “World’s Most Influential Scientific Minds.” Scientists earn a place atop the list by publishing several articles that rank among the top one percent most cited by fellow researchers.

“Citations offer a direct testament to work that scientists themselves judge to be the most important to ongoing research,” said Gordon Macomber, managing director of Thomson Reuters Scientific and Scholarly Research, in a press release.

With that in mind, we combed through the most influential sports science journals to find their top-cited articles over the past five years. Presenting what all that research has to say about our health:

We’re Obsessed With Shortcuts
The Source: Journal of Applied Physiology

We want to go fast. But we don’t want to do the hard work. Nitrate and protein supplement research dominates the literature. Nitrates, found in beetroot juice, were found to make exercise more efficient and help endurance athletes go stronger longer—if they drank 17 ounces of the stuff every day for at least three days before go-time.

And in muscle-building news, the journal’s top-cited study concluded that whey hydrolysate beats out soy protein and casein for post-workout muscle recovery. Athletes who downed a drink with 10 grams of whey hydrosylate after performing resistance exercise had a 93 percent greater muscle protein synthesis response than they did after consuming a drink that contained the same amount of casein.

The takeaway? Everyone’s looking for a fitness shortcut. In reality, diet tweaks and supplements might help you eke out that final percent of performance gain. But for most athletes, sticking to the fundamentals will yield more immediate results.


We Want to Embrance Bionic Technology
The Source: The American Journal of Sports Medicine

Platelet-rich-plasma injections (aka PRP) were the hot topic in this journal. As the top-cited article explains, PRP injections are prepared from one’s own blood, and contain “growth factors and bioactive proteins that influence the healing of tendon, ligament, muscle, and bone.” More and more pro athletes are turning to both stem cell and PRP injections to try to avoid the uncertainty and down time associated with surgery.

Using one’s own blood as a body boost is nothing new. Tour de France cyclists have been extracting their own blood—sometimes centrifuging it down to just the red blood cells, then re-injecting it—for years. As Bike Pure explains, autologous blood transfusion “is not detectable and is perhaps not technically “doping”, but remains a banned technique affording a massive boost to an athlete over fatigued competition” by delivering extra oxygen to working muscles, and “increasing the capacity of the muscles to use oxygen by up to five percent.”

Unlike blood doping, PRP injections are not illegal. In 2011, the World Anti-Doping Agency removed PRP from its list of banned substances after noting a lack of evidence that the procedure enhances performance. PRP is for healing.


We’re Terrified Of Concussions

The Source: British Journal of Sports Medicine

For athletes in contact sports like football, researchers are particularly concerned about concussions: their long-term effects, how to spot one, and how to decide when an athlete is ready to play again after suffering one.

Since top researchers released a popular consensus statement on concussion in sport in late 2008, research on the condition has exploded. We know now, for example, that men take more than twice as long as women to recover from a concussion. (An average of 66.9 days vs. 26.3 days for women, likely because the female hormone progesterone may play a protective role.) And that 10 to 20 minutes of low-intensity aerobic activity can alleviate symptoms and expedite recovery.

Helmet technology is getting smarter, too. In football, the new Riddell SpeedFlex helmet is “designed to disperse energy, reducing the risk of trauma,” SB Nation reports.  A built-in response system “is intended to alert coaches when a player suffers a significant hit to the head, or multiple hits that combine to pose a risk. And in the endurance sports world, Swedish company POC introduced helmets with MIPS, a technology designed to reduce oblique impact forces on the brain by allowing the helmet’s shell and liner to move separately.


We Think Sitting Is Killing Us

The Source: Medicine and Science in Sports and Exercise and Exercise and Sports Sciences Reviews

In perhaps one of the most talked-about studies from this journal, scientists linked time spent sitting to mortality and found that the longer people sit every day, the higher their mortality rate. The revelation brought on a wave of stand-up desk articles and an urge to at least get up every 15 minutes to take a lap around the office.


Over the last several years, researchers have slowly but surely reached the consensus that high intensity interval training (HIIT), which is characterized by relatively short bursts of intense exercise followed by periods of rest, far outperforms conventional aerobic endurance type exercises.

Not only does it beat conventional cardio as the most effective and efficient form of exercise, it also provides health benefits you simply cannot get from regular aerobics, such as a tremendous boost in human growth hormone (HGH), aka the “fitness hormone.”

Perhaps best of all, HIIT requires only minutes, compared to hours, each week. In the featured video, Dr. Michael Mosley, author of Fast Exercise: The Simple Secret of High-Intensity Training, shares his own experiences with HIIT.

The Truth About Exercise

As Dr. Mosley reports in the featured BBC special, groundbreaking research suggests that as little as three minutes of high intensity training per week can produce significant health benefits.

Dr. Mosley was able to improve his insulin sensitivity by 24 percent by putting in a mere 12 minutes of intense exercise per week, for four weeks. Such an effect is truly amazing, and indeed important, as improving and maintaining good insulin sensitivity is perhaps one of the most important aspects of optimal health.

He performed the exercises on a stationary bike. After warming up, he cycled “all-out” for 20 seconds, rested for a couple of minutes, and then gave it his all for another 20 seconds.

The HIIT approach I personally prefer and recommend is the Peak Fitness method of a 50% longer exercise time of 30 seconds of maximum effort followed by less recovery of only 90 seconds for a total of eight repetitions.

When you’re first starting out, depending on your level of fitness, you may only be able to do two or three repetitions, which is perfectly alright. As you get fitter, just keep adding repetitions until you’re doing eight.

About a year ago, I personally modified the number of repetitions I do from eight to six, as it was sometimes just too strenuous for me to do all eight. By listening to my body and cutting it back to six reps, I can now easily tolerate the workout and go full out. Plus, I no longer dread doing it.

I also do alternatives to elliptical now where I will do six sets with a barbell and ten pounds on it and do deadlifts, bent over rows, upright rows, squats, clean and jerks and bicep curls all in rapid succession with no breaks. It is not quite as intense but goes for about 60 seconds and really pushes me metabolically. I also rest for a few minutes until I recover. I think the variety is good.

Another tweak I made is to incorporate Buteyko breathing, which means I do most of the workout breathing only through my nose. This raises the challenge to another level.

There are very compelling reasons for trading your hour-long walk on the treadmill for a 20-minute high intensity routine, and research shows that in this case, less time can indeed lead to a greater payout, if done correctly. As Dr. Mosley writes in his book, Fast Exercise:

“I believe that we have now produced sufficient data to be able to recommend short bursts of high-intensity exercise as a safe and effective alternative to conventional workouts, removing the ‘time barrier’ as an excuse for not exercising.

This will hopefully boost compliance and help people take up an approach that will lead to a healthier way of life. The great thing about HIIT is that it can be done in the workplace or at home without preplanning or missing an episode of your favorite TV show.”


Even Brief Intense Exercise Produces Genetic Changes That Promote Fat Loss

A study published in the journal Cell Metabolism1 in 2012, showed that when healthy but inactive people exercise intensely, even if the exercise is brief, it produces an immediate change in their DNA. While the underlying genetic code in the muscle remains unchanged, exercise causes important structural and chemical changes to the DNA molecules within the muscles.

This contraction-induced gene activation appears to be early events leading to the genetic reprogramming of muscle for strength, and to the structural and metabolic benefits of exercise. Several of the genes affected by an acute bout of exercise are genes involved in fat metabolism. Specifically, the study suggests that when you exercise, your body almost immediately experiences genetic activation that increases the production of fat-busting proteins! Besides lowered body fat, other benefits associated with high intensity interval training include:

• Improved muscle tone
• Firmer skin and fewer wrinkles
• Higher energy levels
• Improved athletic speed and performance
• Boosted sex drive

Intermittent Movement—Another Crucial Piece of the Puzzle

In the video, Dr. Mosley also meets with Dr. James Levine, a Mayo Clinic obesity expert whose research suggests that the best way to lose weight is to increase your non-exercise activity thermogenesis, also referred to as NEAT. This is the calories you expend during your day-to-day living, through body movement that have nothing to do with traditional exercise.

Similar research has been conducted by Dr. Joan Vernikos, former director of NASA’s Life Sciences Division and author of Sitting Kills, Moving Heals.

Mounting research clearly shows that undisrupted sitting for long periods of time is an independent risk factor for chronic disease and early death—even if you exercise vigorously each week. More and more, we’re starting to realize the importance of keeping your body in perpetual motion—bending, stretching,  reaching, standing up…

Using so-called “fidget pants,” Dr. Levine measures how much Dr. Mosley and other volunteers move during any given day, and how that non-exercise movement translates into calories burned. As it turns out, even slight increases in daily motion can result in several hundreds of calories burned.

When asked which might be more important for health: intermittent bursts of high intensity exercise a few times a week, or more or less non-stop non-exercise movement throughout the day, Dr. Levine notes that those who exercise regularly will clearly continue to do so because they love it.

But a large section of the population gets no exercise whatsoever and think nothing of it. For those people, paying careful attention to their intermittent movements—the movement inherent in their daily living—becomes incredibly relevant and important for their health. In a nutshell, the key to optimal health is to “keep off your bottom as much as possible.” It’s just that simple. That in no way detracts from the importance or benefits you can reap from a regular fitness regimen though.

According to Dr. Levine, “there should never be an hour where you’re sitting down.” One solution, provided your job can accommodate it, is to do your work standing up. Another solution, suggested by Dr. Vernikos, is to make sure you stand up at least once every 15 minutes or so. In a previous article, I collected a list of 30 videos demonstrating quick and simple exercises you can do when you stand up.

What Makes High Intensity Exercise So Effective

Getting back to high intensity exercise, part of the key that makes HIIT so effective is that it engages far more of your muscle tissue than conventional aerobic cardio exercise. You have three different types of muscle fibers: slow, fast, and super-fast. Only ONE of these muscles, the super-fast fibers, will impact your production of human growth hormone (HGH), which is KEY for strength, health, and longevity. The vast majority of people, including many athletes such as marathon runners, only train using their slow muscle fibers. In fact, neither traditionally performed aerobic cardio nor strength training will work anything but your slow muscles. These are the red muscles, which are filled with capillaries and mitochondria, and hence a lot of oxygen.

The fast type of fiber, which is also red muscle that oxygenates quickly, is five times faster than the slow fibers. Power training, or plyometric burst-type exercises, will engage these fast muscles. The super-fast ones are the white muscle fibers. They contain far less blood and less densely packed mitochondria. These muscle fibers are what you use when you do anaerobic, short burst exercises. High intensity burst-type exercises are the ones that will engage these super-fast fibers. They’re 10 times faster than slow fibers, and activating them is the key to producing growth hormone! To further maximize your growth hormone release, you’ll want to:

• Get a good night’s sleep
• Optimize your vitamin D levels

Avoid sugar, especially fructose. (If you consume sugar or fructose, especially within two hours post-exercise, you will virtually obliterate the production of growth hormone!


Tips for Building a High-Quality Fitness Regimen

Ideally, intense exercise should be balanced with strength training, proper stretching, core strengthening, stress reduction, restorative sleep, and good nutrition. You’ll find much more information about HIIT and other types of exercise in the fitness section of my website. When putting together your exercise routine, I recommend incorporating the following:

1- Stand Up Every 15 Minutes. Compelling research now tells us that prolonged sitting can have a tremendously detrimental impact on your health, even if you exercise regularly. Your body needs to interact with gravity in order to function properly, and this has to be ongoing, throughout your day. Whenever you have a chance to move your body, do so! I invite you to look at our list of 30 videos for ideas about what you can do when you stand up.
2- Interval Peak Fitness (Anaerobic) Training: Interval training involves alternating short bursts of high-intensity exercise with gentle recovery periods, and are central to my Peak Fitness routine.
3- Strength Training: Rounding out your exercise program with a one-set strength training routine will ensure that you’re really optimizing the health benefits of your fitness program. You can also “up” the intensity by slowing it down. For more information about using super slow weight training as a form of high intensity interval exercise, please see my interview above with Dr. Doug McGuff, and my video about super slow workouts at the top of this section.
4- Core Exercises: Your body has 29 core muscles located mostly in your back, abdomen, and pelvis. This group of muscles provides the foundation for movement throughout your body, and strengthening them can help protect and support your back, make your spine and body less prone to injury, and improve your balance and stability. Foundation Training, created by Dr. Eric Goodman, is an integral first step of a larger program he calls “Modern Moveology,” which consists of a catalog of exercises.
5- Stretching: My favorite type of stretching is Active Isolated Stretching (AIS). With AIS, you hold each stretch for only two seconds, which works with your body’s natural physiological makeup to improve circulation and increase the elasticity of muscle joints. This technique allows your body to repair itself and prepare for daily activity. You can also use devices like the Power Plate to help you stretch.

By Dr. Mercola

More than 1,660,290 new cancer cases are projected to be diagnosed in the US this year, and an estimated 580,350 Americans will die from the disease. Another 600,000 Americans die of heart disease each year.2 At present, heart disease is the leading cause of death among both sexes.

Despite massive technological advances over the past half-century, Western medicine is still at a loss for how to rein in the prevalence of these top two killers.

It’s become increasingly clear that many of the conventional strategies, from diagnosis to treatment, are riddled with flawed assumptions and approaches that, in many cases, do more harm than good.

What’s worse, virtually none of the conventional strategies actually address the root cause of the problem, a flawed diet high in sugars and processed foods.

In fact, conventional dietary recommendations for the prevention of heart disease are diametrically opposed to what you actually need for optimal heart health! For over 60 years, saturated fats have been blamed for heart disease, resulting in the promulgation of a dangerous low-fat, high-sugar diet.

In reality, a diet that promotes health is high in healthful fats and very, very low in sugar and non-vegetable carbohydrates… Research coming out of some of America’s most respected institutions now confirms that sugar is a primary dietary factor driving chronic disease development.

Sugar, and fructose in particular, has been implicated as a culprit in the development of both heart disease and cancer, and having this information puts you in the driver’s seat when it comes to prevention.

How Much Sugar Is in Your Diet?

Ever since I started this Web site back in 1997, I’ve been warning about the dangers of high sugar consumption. It’s important to realize that even if you don’t add sugar to your foods, hidden sugar, typically in the form of high fructose corn syrup (HFCS), is in virtually all processed foods, from yogurts and sauces to breads and sodas.

Many favorite staples are also grain-based, such as bagels, pancakes, and breakfast cereals. All those grains are also quickly turned into sugar in your body, adding to your sugar burden.

Clinical trials have shown that those who consume HFCS tend to develop higher risk factors for cardiovascular disease within as little as two weeks, so if I had to pick out the worst culprit among sugars, it would be fructose.

Other studies indicate that if you limit your sugar, no matter what form you get it in, you effectively decrease your chances of developing cancer—including breast and colon cancers.

Soda Drinkers Have Increased Cancer Risk

According to recent research,3, 4 older women who drink a lot of soda or other sugary beverages may be at significantly increased risk for endometrial cancer—an estrogen-dependent type of cancer that affects the lining of a woman’s uterus.

The study included data for more than 23,000 postmenopausal women who were followed for 14 years.

Women who had the highest intake of sugary beverages had a whopping 78 percent higher risk for endometrial cancer, and the risk appeared to be dose dependent; rising right along with consumption. Study author Maki Inoue-Choi was not surprised by the results, and neither am I.

“Other studies have shown increasing consumption of sugar-sweetened beverages has paralleled the increase in obesity. Obese women tend to have higher levels of estrogens and insulin than women of normal weight, [and] increased levels of estrogens and insulin are established risk factors for endometrial cancer,” she said.5

Previous research has also shown that dietary fructose can promote cancer growth in a number of different ways, including:

• Altered cellular metabolism
• Increased reactive oxygen species (free radicals)
• DNA damage
• Inflammation

Fructose Promotes Cancer Cell Proliferation

Studies have shown that different sugars are metabolized using different metabolic pathways, and this is of MAJOR consequence when it comes to feeding cancer and making it proliferate. Three years ago, researchers published findings showing that fructose is readily used by cancer cells to increase their proliferation.6 Cancer cells did not respond to glucose in the same manner.

In this case, the cancer cells used were pancreatic cancer, which is typically regarded as the most deadly and universally rapid-killing form of cancer. According to the authors:

“Traditionally, glucose and fructose have been considered as interchangeable monosaccharide substrates that are similarly metabolized, and little attention has been given to sugars other than glucose. However, fructose intake has increased dramatically in recent decades and cellular uptake of glucose and fructose uses distinct transporters.

Here, we report that fructose provides an alternative substrate to induce pancreatic cancer cell proliferation. Importantly, fructose and glucose metabolism are quite different; in comparison with glucose, fructose… is preferentially metabolized via the nonoxidative pentose phosphate pathway to synthesize nucleic acids and increase uric acid production.

These findings show that cancer cells can readily metabolize fructose to increase proliferation. They have major significance for cancer patients given dietary refined fructose consumption, and indicate that efforts to reduce refined fructose intake or inhibit fructose-mediated actions may disrupt cancer growth.” [Emphasis mine]

The study confirms the old adage that sugar feeds cancer because they found that tumor cells do thrive on sugar (glucose). However, the cells used fructose for cell division, speeding up the growth and spread of the cancer. This difference is clearly of major consequence, and should be carefully considered by anyone who is currently undergoing cancer treatment or seeking to prevent cancer. 

This does not mean you should avoid fruits, the benefits of most fruits outweigh any concerns to fructose. I would suggest to not juice your fruits and to eat them whole, and also realize we have bred many of these fruits to a very high level of fructose. Fruits today are many times sweeter than they were historically, and should be consumed in moderation. The real problem is the high fructose corn syrup that is added to practically every processed food and drink you see.

Remember: Exercise Is Another Potent Ally Against Cancer and Heart Disease

Controlling your blood-glucose and insulin levels—through diet, along with a comprehensive exercise program—can be one of the most crucial components to a cancer recovery program. These factors are also crucial in order to prevent cancer in the first place. Diet and exercise—particularly high intensity interval training—are also the dynamic duo that will help you stave off heart disease.

In fact, a recent meta-analysis that reviewed 305 randomized controlled trials found no statistically detectable differences between exercise and medications for heart disease, including statins and beta blockers. (Previous research has also shown that exercise alone can reduce your risk of cardiovascular disease by a factor of three,7 which isn’t too shabby.) Exercise is in fact so potent, the researchers suggested that drug companies ought to be required to include it for comparison when conducting clinical trials for new drugs. As reported by Bloomberg:8

“The analysis adds to evidence showing the benefit of non-medical approaches to disease through behavior and lifestyle changes… ‘In cases where drug options provide only modest benefit, patients deserve to understand the relative impact that physical activity might have on their condition,’ Naci and Ioannidis said in the published paper. In the meantime, ‘exercise interventions should therefore be considered as a viable alternative to, or, alongside, drug therapy.’”

In a nutshell, being a healthy weight and exercising regularly creates a healthy feedback loop that optimizes and helps maintain insulin and leptin receptor sensitivity. And, as I’ve mentioned before, insulin and leptin resistance—primarily driven by excessive consumption of refined sugar and grains along with lack of exercise—are the underlying factors of nearly all chronic disease.

Connecting the Dots: Fructose—Uric Acid—Cancer and Chronic Disease Risk

The theory that sugar feeds cancer was actually born nearly 80 years ago. Shockingly, most conventional cancer programs STILL do not adequately address diet and the need to avoid sugars. The 1931 Nobel laureate in medicine, German Otto Warburg, Ph.D., first discovered that cancer cells have a fundamentally different energy metabolism compared to healthy cells. Malignant tumors tend to use a process where glucose is used as a fuel by the cancer cells, creating lactic acid as a byproduct.9

The large amount of lactic acid produced by this fermentation of glucose from cancer cells is then transported to your liver. This conversion of glucose to lactic acid generates a lower, more acidic pH in cancerous tissues as well as overall physical fatigue from lactic acid buildup.10, 11

This is a very inefficient pathway for energy metabolism, which extracts only about five percent of the available energy in your food supply. In simplistic terms, the cancer is “wasting” energy, which leads you to become both tired and undernourished, and as the vicious cycle continues, will lead to the body wasting so many cancer patients experience. Additionally, carbohydrates from glucose and sucrose significantly decrease the capacity of neutrophils to do their job. Neutrophils are a type of white blood cell that helps cells to envelop and destroy invaders, such as cancer.

While all forms of sugar are detrimental to health in general and promote cancer, but in slightly different ways and to a different extent, fructose clearly seems to be one of the overall most harmful. As mentioned above, fructose metabolism leads to increased uric acid production along with cancer cell proliferation.12 Again, ONLY fructose (not glucose) drives up your uric acid levels.

Now, the connection between fructose, uric acid, and insulin resistance is so clear that your uric acid level can actually be used as a marker for toxicity from fructose. What this means is that if your uric acid levels are high, you’re at increased risk of all the health hazards associated with fructose consumption—including both heart disease and cancer. Subsequently, you’d be well advised to reduce your fructose intake. For more information about this, please see my previous interview with Dr. Richard Johnson, who is an expert on this topic. Two key recommendations however are:

• Keep your uric acid level below 4 mg/dl for men and 3.5 mg/dl for women, and
• As a standard recommendation, I strongly advise keeping your TOTAL fructose consumption below 25 grams per day

Reeling in Your Fructose Consumption May Be the Most Important Lifestyle Change You Can Make

Dr. Johnson has written one of the best books on the market on the health dangers of fructose, called The Sugar Fix, which explains how fructose causes high blood pressure, heart disease, obesity, diabetes, and kidney disease. It’s also safe to say that many cancers are also on the list of diseases that are directly linked to excessive fructose consumption. In addition to the studies already mentioned, fructose has also been found to promote metastasis in breast cancer,13 and shows genotoxic effects on the colon in animal research.14

Fructose also promotes a condition called intracranial atherosclerosis15—a narrowing and hardening of the arteries in your skull—and contrary to popular belief, it is the sugar/fructose in your diet that increases your risk for heart disease, NOT saturated animal fats.

At the basic dietary level, the prevention strategies for heart disease and cancer are identical. First and foremost, you need to address your insulin and leptin resistance, which is the result of eating a diet too high in sugars and grains—again, not fat, with the exception of trans fats from partially hydrogenated vegetable oils, which have been linked to increased heart disease risk, even in small amounts. To safely and effectively reverse insulin and leptin resistance, you need to:

• Avoid sugar, processed fructose, grains if you are insulin and leptin resistant, and processed foods
• Eat a healthful diet of whole foods, ideally organic, and replace the grain carbs with:
• Large amounts of vegetables
• Low-to-moderate amount of high-quality protein (think organically raised, pastured animals)
• As much high-quality healthful fat as you want (saturated and monosaturated from animal and tropical oil sources). Most people actually need upwards of 50-85 percent fats in their diet for optimal health—a far cry from the 10 percent currently recommended.

Restricting Fructose Consumption Is Crucial Part of a Healthy Lifestyle

Whether we’re talking about heart disease or cancer, reducing (or preferably eliminating) fructose and other added sugars, as well as limiting grain carbohydrates from your diet is a primary strategy on my list if you have insulin and leptin resistance. This dietary modification should also be part of your comprehensive treatment plan if you’ve been diagnosed with either cancer or heart disease.

Understand that excessive fructose consumption leads to insulin resistance, and insulin resistance appears to be the root of many if not most chronic disease, including heart disease and cancer. So far, scientific studies have linked excessive fructose consumption to about 78 different diseases and health problems.16

By severely reducing your intake of fructose and carbs in your diet, you help stave off any potential cancer growth, and “starve” any tumors you currently have. It also bolsters your overall immune function, because sugar decreases the function of your immune system almost immediately.
By Dr. Mercola