Fitness Resources

Author: Mark Mayes

How Effective—and Sustainable—are Popular Diets in Real Life? American Council on Exercise by American Council on Exercise Contributor

Specialized diets have become so common that it’s no longer unusual to find specific diet−related options on restaurant menus (such as gluten-free, dairy-free and vegan), or for dinner party hosts to ask their guests if they have any dietary restrictions that need to be accounted for. While some people follow restricted food plans for medical or health reasons, others do so by choice because they believe these diets will help them lose weight or live longer. This includes, among others, intermittent fasting (IF), paleo and the Mediterranean diet.

While these diets have been the focus of a growing body of research, particularly in terms of their effects on weight and longevity, many of these studies are conducted under the controlled setting of a supervised program. Currently, there isn’t a lot of research to demonstrate the effectiveness of these diets in the real world.

A research team at the University of Otago in New Zealand set out to close the gap of knowledge about the real-world efficacy of some of today’s most popular diets. Specifically, researchers sought to examine the long-term effects of following IF, paleo or Mediterranean diets in a real-world setting. Participants self-selected which diet they wished to follow, without any ongoing support from a dietitian.

Intermittent fasting (IF) involves limiting energy intake to about 25% of one’s usual diet (500 calories for women and 600 calories for men) on two self-selected days per week.

The Mediterranean diet encourages consumption of fruit, vegetables, whole-grain breads and cereals, legumes, nuts, seeds and olive oil, with moderate amounts of fish, chicken, eggs and diary and red meat once a week or less.

The paleo diet consists of mostly less-processed foods with an emphasis on eating fruit and vegetables, animal proteins, nuts, coconut products and extra-virgin olive oil. While “original” paleo diets strictly exclude all legumes, dairy and grains, this study used a modified version that included some dairy as well as up to one serving daily of legumes and grain-based food.

During the year-long study, which included 250 healthy adults with overweight and was published in the American Journal of Clinical Nutrition, researchers concluded that there were some weight loss and health benefits for adults with overweight who followed the Mediterranean, IF and paleo diets, though adherence to the diets dropped off considerably during the course of the year.

While IF led to slightly more weight loss than the other diets, the Mediterranean diet also improved blood sugar levels.

No Single, Right Diet

Co-lead author Dr. Melyssa Roy, a research fellow in the University of Otago’s Department of Medicine, says the amount of weight loss was modest—on average 4.4 to 8.8 pounds (2 to 4 kg), but those who followed the fasting or Mediterranean diets also experienced clinically significant improvements in blood pressure.

Dr. Roy says the evidence shows that, for some people, the Mediterranean, fasting or paleo diets can be “healthful, beneficial ways to eat.”

“This work supports the idea that there isn’t a single ‘right’ diet,” explains Dr. Roy. Rather, “there are a range of options that may suit different people and be effective. In this study, people were given dietary guidelines at the start and then continued with their diets in the real world while living normally.” Dr. Roy says that about half of the participants were still following their diets after a year and had experienced improvements in markers of health.

“Like the Mediterranean diet, intermittent fasting and paleo diets can also be valid healthy eating approaches—the best diet is the one that includes healthy foods and suits the individual,” says Dr. Roy.

Co-lead author Dr. Michelle Jospe, a postdoctoral fellow in the University of Otago’s Department of Medicine, says that, according to the results of their study, participants found the Mediterranean diet easiest to adhere to.

“Our participants could follow the diet’s guidelines more closely than the fasting and paleo diets and were more likely to stay with it after the year, as our retention rates showed,” explains Dr. Jospe.

Most of the 250 participants (54%) chose IF, while 27% chose the Mediterranean diet and 18% the paleo diet. After 12 months, the Mediterranean diet had the best retention rate, with 57% of participants continuing to adhere to the diet; by comparison, after one year, 54% were still fasting and 35% were still on the paleo diet.

After 12 months, participants who chose IF lost an average of 8.8 pounds (4.0 kg), while those on the Mediterranean diet lost an average of 6.2 pounds (2.8 kg) and those on the paleo diet lost an average of 4 pounds (1.8 kg).

Reduced systolic blood pressure was observed among those following the fasting and Mediterranean diets, together with reduced blood sugar levels in the Mediterranean diet.

Dr. Jospe explains that participants who said they were still following their diet at 12 months lost even more weight, showing the importance of choosing a diet that is sustainable. She believes the results of this study are relevant to the thousands of people following self-chosen diets with little supervision and indicates more realistic outcomes.

What This Research Means to Health and Exercise Professionals

Obesity remains a worldwide public health issue. More than 1.9 billion adults worldwide meet the criteria for obesity or overweight, according to the World Health Organization. It is associated with, and contributes to, a shortened life span, type 2 diabetes, cardiovascular disease, some cancers, kidney disease, sleep apnea, osteoarthritis and other conditions. Weight loss can lower the risk of developing these conditions and improve health outcomes. As a health and exercise professional, you are well positioned to provide the guidance individuals need to lose weight and, ultimately, reduce their risk of these diseases and improve their overall health and quality of life.

While your ultimate goal is to help your clients achieve permanent lifestyle change, helping clients who struggle with obesity lose as little as 5% of their body weight can go a long way toward improving their health and well-being. For this reason, the best answer to the question of which “diet” is best for weight loss is the one that an individual will be able to stick to long-term.

Of course, it is beyond your scope of practice as a health and exercise professional to offer specific diet plans to your clients. However, as with so much related to health and wellness, knowledge is power. Informing your clients about nutrition-related research empowers them to make healthy, informed decisions about the food they consume—not just in the short-term to lose weight, but in the long-term for overall health and wellness.

Best and Worst Diets of 2020: U.S. News and World Report Annual Rankings

Posted in

Tuesday, Feb 18, 2020

A shocking 70% of American adults are either overweight or obese.* During any given year, an estimated 45 million Americans are “on a diet.” As our waistlines grow, so does the cost of health care. We can no longer afford to ignore the obesity epidemic in this country.

Obesity is strongly associated with a number of chronic conditions including cardiovascular disease, type 2 diabetes, knee osteoarthritis, and some cancers

With over two-thirds of the population overweight, it’s no wonder the weight loss industry in the U.S. exceeded $72 billion in revenue in 2019. Promises of rapid, life-changing weight loss rarely live up to the hype, and many diets are questionable at best.

BEST DIETS  |  WORST DIETS  

What the Experts Said  |  Definitions Used in Rating the Diets


  RANKING THE DIETS  

Each year, U.S. News and World Report releases their annual ratings of popular diets. Some diets are deemed safe, nutritious, heart-healthy and effective for weight loss. Other diets are strongly criticized for restrictiveness, nutritional deficiency, safety and sustainability.

For 2020, a team of 25 nutrition experts, including registered dietitians, physicians, and nutrition scientists rated the effectiveness of 35 different diets in the following areas:

  • easy to follow
  • nutritious
  • safe
  • effective for weight loss
  • protective against diabetes
  • protective against heart disease

(Additional details regarding these areas can be found at the end of the blog.)

After scoring each diet in each area, the team ranked the diets in several different categories, including:

  • best/worst diets overall
  • best/worst weight-loss diets
  • best/worst diets for healthy eating
  • best/worst heart-healthy diets
  • easiest/hardest diets to follow

  BEST DIETS  


In the best diets overall category, the Mediterranean Diet came out on top, followed closely by DASH Diet, while the Flexitarian Diet and Weight Watchers Diet finished third and fourth, respectively.

In the best heart-healthy diets category, the Ornish Diet led the pack, followed closely by the Mediterranean and DASH diets.

  WORST DIETS  

At the other end of the spectrum, the Ketogenic Diet and the Dukan Diet finished dead last at #34 and #35, respectively. The Alkaline Diet and Paleo Diet also ranked poorly at 28th and 29th respectively, in the best diets overall category.

For heart health, the Whole30 Diet and the Dukan Diet brought up the rear behind other dietary losers like Alkaline, Keto and Paleo.

  WHAT THE EXPERTS SAID  

You might be interested in some of the specific comments made by the expert panel regarding some of these diets:

  • MEDITERRANEAN DIET:  A Mediterranean style eating plan will showcase healthy foods like whole-grain pita and hummus, salads, fresh fruits and veggies, and beneficial fats found in foods such as salmon, nuts, and olive oil.
  • DASH DIET:  The Dietary Approaches to Stop Hypertension (DASH) plan was lauded for its nutritional completeness and safety, as well as its ability to help prevent and treat hypertension.
  • ORNISH DIET:  The Ornish diet is nutritionally sound, safe and heart-healthy. While it is great for reversing or preventing heart disease and diabetes, it’s not easy to adhere to the severe fat restriction.
  • KETO DIET:  With the combination of unusually high saturated fat plus remarkably low carb and fiber content, experts had enough reservations to place the highly-popular Keto Diet way down in the best diets overall category. They seemed equally concerned about the sustainability of this diet and its implications for heart health, citing a 2019 article in JAMA Internal Medicine that concluded “enthusiasm outpaces evidence” when it comes to a keto diet for treating obesity and diabetes.
  • PALEO DIET:  Slapping the Paleo Diet with multiple low scores, the experts couldn’t accept that entire food groups, like dairy and grains, as well as legumes are excluded, making it hard for dieters to get all the nutrients they need. Paleo was deemed too restrictive to be healthy or sustainable.
  • ALKALINE DIET:  Experts dealt the Alkaline Diet mostly low scores, pronouncing it difficult to follow and noting that its nutrition profile isn’t ideal. They also noted a lack of research to support claims made by proponents.

  DEFINITIONS USED IN RATING THE DIETS  

  • Short-term weight loss. Likelihood of losing significant weight during the first 12 months, based on available evidence
  • Long-term weight loss. Likelihood of maintaining significant weight loss for two years or more, based on available evidence
  • Diabetes. Effectiveness for preventing diabetes or as a maintenance diet for diabetics
  • Heart. Effectiveness for cardiovascular disease prevention and as a risk-reducing regimen for heart patients
  • Ease of compliance. Based on the initial adjustment, satiety (a feeling of fullness so that you’ll stop eating), taste appeal, special requirements
  • Nutritional completeness. Based on conformance with the federal government’s 2015-2020 Dietary Guidelines for Americans, a widely accepted nutritional benchmark
  • Health risks. Including malnourishment, specific nutrient concerns, overly rapid weight loss, contraindications for certain populations or existing conditions, etc.

*Overweight in adults is defined as a body mass index (BMI) between 25.0 and 29.9 kg/m2, while obesity is defined as a BMI greater than or equal to 30 kg/m2. Use this link to calculate your BMI.

Please note that BMI is not a valid indicator of body weight status for individuals who are extremely muscular. However, such individuals make up only a tiny portion of the U.S. population. 

Reference

Best Diets, 2020. U.S. News and World Report.

Insomnia Linked to Refined Carbs Research suggests refined carbs and sugar can lead to sleep problems.

By
Feb 3, 2020

Carbs and insomnia

A new study on insomnia in postmenopausal women suggests that consuming refined carbohydrates may keep you awake. The findings were published online in The American Journal of Clinical Nutrition.

Investigators analyzed food diaries from more than 50,000 participants in the Women’s Health Initiative and looked at whether women with a higher dietary glycemic index were more likely to develop insomnia.

Previously, researchers have been unable to confirm whether refined carbs trigger insomnia or whether insomnia causes individuals to eat more sweets. In this study, investigators sought to determine the role of carbs in creating sleep problems by looking for the emergence of insomnia across different types of diet.

The link they discovered between high glycemic diets and insomnia can be attributed to the quick spike in blood sugar after eating highly refined carbohydrates, like added sugars, white bread, white rice and soda. An increase in blood sugar causes the body to release insulin and other hormones—such as adrenaline and cortisol—that interfere with sleep.

The study also found that women whose diets contained higher amounts of vegetables, fiber and whole fruits were less likely to develop insomnia.

“Whole fruits contain sugar, but the fiber in them slows the rate of absorption to help prevent spikes in blood sugar,” said the study’s senior author, James Gangwisch, PhD, assistant professor of clinical psychiatric social work at Columbia University Vagelos College of Physicians and Surgeons, in a ScienceDaily press release “This suggests that the dietary culprit triggering the women’s insomnia was the highly processed foods that contain larger amounts of refined sugars that aren’t found naturally in food.”

While the research focuses primarily on postmenopausal women, the effects of carbs on blood sugar are true for most people and suggest the study has broader applications.

“Based on our findings, we would need randomized clinical trials to determine if a dietary intervention, focused on increasing the consumption of whole foods and complex carbohydrates, could be used to prevent and treat insomnia,” said Gangwisch.

ACE-Sponsored Research: Can Foam Rolling Improve Sports Performance? by Daniel J. Green Contributor Certified™: February 2020

By Olivia Stovern, MS, Carley Henning, MS, John P. Porcari, PhD, Scott Doberstein, MS, Kari Emineth, MS, Blaine Arney, MS, and Carl Foster, PhD, with Daniel J. Green

This study was first published in the peer-reviewed International Journal of Research in Exercise Physiology.

Foam rollers, which are a mainstay in many fitness facilities, are often used as a form of self–myofascial release (SMR) during the warm-up of an exercise session or as a means of recovery between workouts. But what exactly is foam rolling meant to accomplish and how effective is it at achieving those objectives?

First, a primer on fascia and SMR: Understanding the concept behind SMR requires an understanding of the fascial system itself. Fascia is a densely woven, specialized system of connective tissue that covers and unites all of the body’s compartments. The result is a system in which each part is connected to the other parts through this web of tissue. Essentially, the purpose of the fascia is to surround and support the bodily structures, which provides stability as well as a cohesive direction for the line of pull of muscle groups. In a normal healthy state, fascia has a relaxed and wavy configuration. It has the ability to stretch and move without restriction. However, with physical trauma, scarring or inflammation, fascia may lose its pliability. SMR is a technique that applies pressure to tight, restricted areas of fascia and underlying muscle in an attempt to relieve tension and improve flexibility.

Figure 1
Fascia

The mechanisms and benefits of performing SMR on a foam roller are unclear, as research findings are often inconclusive or inconsistent. There are a few different potential reasons for this, including the fact that no standard protocol for foam rolling exists. Therefore, when trying to draw conclusions by looking at the results of multiple studies, it’s often a case of comparing apples to oranges.

In an effort to bring some clarity to the topic, ACE asked John P. Porcari, PhD, and his research team in the Department of Exercise and Sport Science at the University of Wisconsin–La Crosse to evaluate the training effects of foam rolling on lower-body flexibility and mobility and performance.

The Study

The research team recruited 34 volunteers to participate in the study (Table 1). Due to the physical demands of the testing and training procedures, participants were required to be at least recreationally active (i.e., exercise a minimum of three times per week for at least 30 minutes) and have no prior lower-leg injuries or cardiovascular or orthopedic contraindications to exercise. The participants were placed into either a foam-rolling group or control group.

The study began with all participants attending an orientation session, during which they had a chance to practice all of the tests that were later administered as part of the study. In addition to height and weight, the following baseline data were collected during this session after a five-minute warm-up: ankle and knee range of motion (ROM), hamstring flexibility, vertical jump height and agility.

It is important to note that ROM and flexibility were measured using active assessments. For example, the participants were asked to dorsiflex the ankle as far as possible while seated upright on a table with legs straight and only the ankles off the edge of the table, at which point the measurement was taken. Dr. Porcari suggests that the difference between active and passive assessments (wherein a researcher pushes the ankle to achieve maximal dorsiflexion) may be another possible cause of some of the conflicting data found in the research on the topic of SMR.

To measure knee flexion, participants laid prone with their knees at the edge of the table and were instructed to flex their knees as much as possible. Hamstring flexibility was assessed using a sit-and-reach test. Finally, a vertical jump test to assess muscular power was conducted, as well as the T-test to assess agility (Figures 2 and 3).

Figure 2
Vertical jump
Figure 3
T-test

The foam-rolling group participated in instructor-led sessions three days per week for six weeks. Each session consisted of foam rolling the lower back, buttocks, quadriceps, hamstrings, calves and iliotibial bands. Specific instructions were provided on how to foam roll each body part, including demonstrations by the researchers to ensure proper technique.

Each body part was foam rolled for 20 seconds and the entire sequence was repeated three times; each session lasted approximately 15 minutes.

Members of both groups were instructed not to change their dietary or exercise habits over the course of the six-week period. After the six weeks, all participants were reevaluated using the same assessment battery used at the beginning of the study. In addition, those in the foam rolling group were asked to complete a Perceived Performance Improvement Questionnaire.

The Results

All 34 participants completed the assessment protocol, and all members of the foam-rolling group completed 18 foam-rolling sessions during the six-week training period.

There was no change in body weight for either group. Data for all of the criterion measures are presented in Table 2. There were no significant changes in knee ROM, vertical jump or T-test time for either group. The foam-rolling group had a statistically significant increase in sit-and-reach distance from pre- to post-testing, which was also statistically significantly greater than the change in the control group. The results for ankle ROM were inconclusive, as both groups had statistically significant improvements in ankle ROM over the course of the study.

Answers to the Perceived Performance Improvement Questionnaire are presented in Table 3. It was found that the foam-rolling group felt more flexible and felt like they could jump higher at the conclusion of the study.

The Bottom Line

The purpose of this study was to determine the training effect of foam rolling on ankle and knee ROM, hamstrings flexibility, agility and vertical jump height. This research found a statistically significant improvement in lower back and hamstring flexibility (as measured by the sit-and-reach test) after six weeks of foam rolling. In addition, foam rolling did not negatively affect athletic performance, as measured by agility or vertical jump height.

“The fact that foam rolling does not do any harm in terms of performance is an important finding,” says Dr. Porcari. “This means that—in contrast to static stretching—foam rolling may be performed during the warm-up, potentially without any negative effect.”

In addition, the participants reported that, while foam rolling can sometimes be uncomfortable or even painful, they felt good afterward. And, as Table 3 shows, most participants felt more flexible and like they could jump higher at the end of the study, and about half felt they had improved in all elements tested. These findings regarding the perceived benefits may explain some of the allure of foam rolling, despite the lack of conclusively supportive evidence.

Expand Your Knowledge

Understanding the Facial Network [online course]

 

Fruits and Veggies Silence Fat Genes Plant foods may help dim the demands of noisy genetics.

By
Jan 8, 2020

Fruit and Obesity

True, some people did not win the genetic lottery with respect to gaining pounds, but that doesn’t mean they can’t tweak their diets to stave off weight creep. A study in The American Journal of Clinical Nutrition involving more than 14,000 adults over a 20-year period discovered that increasing one’s intake of fruits and vegetables can be protective against a genetic susceptibility to obesity. The impact was more robust in people whose genes strongly edged them toward obesity, and the most effective choices for overriding fat genes were berries, citrus fruits and leafy green vegetables.

January 2020 Question of the Month: Are Nutrition Supplements a Flop?

By Matthew Kadey, MS, RD Dec 17, 2019

Nutrition and diet supplements not useful

Supplements are a multibillion-dollar industry in America, but recent studies continue to call into question their usefulness. In a large analysis of 277 randomized trials, researchers from West Virginia University, Johns Hopkins and elsewhere found no proof that vitamin, mineral and other nutritional supplements could help stave off heart disease or prolong life, though there was some weak evidence that omega-3 fat supplements might be beneficial.

In another study, researchers at Tufts University analyzed dietary data from 30,899 U.S. adults and then followed the subjects for a median of 6 years. Their findings: Eating adequate amounts of vitamins and minerals from food was associated with fewer deaths from diseases like cancer, whereas vitamins and minerals from supplements had no protective effect.

And in JAMA Cardiology, a meta-analysis of 21 studies did not find evidence that vitamin D supplements reduce rates of heart disease or all-cause mortality.

Are there any supplements that you use and feel are effective? What do you say to (or ask) clients who are taking nutrition supplements? Do you believe people should focus on getting their nutrients from food instead of supplements?

 Send your answers to Sandy Todd Webster at swebster@ideafit.com.

Gluten-Free Thanksgiving Sides: 6 Ideas by Katie Ferraro on November 20, 2018

Do you have a gluten-free family member or friend attending Thanksgiving dinner this year?If the thought of trying to make gluten-free Thanksgiving dishes sounds daunting, we’ve got you covered. Here are six delicious ideas for gluten-free Thanksgiving side dishes.

Start With the Stuffing
Traditional stuffing doesn’t work for the gluten-free group because it’s made with bread. Fortunately, gluten-free bread has come a long way in recent years, and many varieties and brands taste every bit as good as their gluten-containing counterparts. You can easily substitute store-bought gluten-free bread in a traditional stuffing recipe. Stick to gluten-free breadcrumbs or make your own from gluten-free bread mixed with shredded cheese to top off the stuffing.

Bright Green Brussels Sprouts Salad
Kick up the color of your Thanksgiving spread by serving a shaved Brussels sprouts salad. Simply shred or very thinly slice raw Brussels sprouts and add lemon juice, olive oil, shredded or shaved Romano cheese, and roasted pistachios, pine nuts or pepitas for a gluten-free side dish that is sure to please everyone’s palate.

Sweet Potato Casserole
Whether you make your sweet potato casserole with or without butter and brown sugar, one of the greatest things about this dish is that sweet potatoes are naturally gluten-free. Both white and orange sweet potatoes are packed with nutrition and are a great carbohydrate-rich side dish to serve your gluten-free guests.

Gluten-free Gravy
Regular gravy is usually thickened with all-purpose flour, which is not an option for gluten-free eaters. Instead, look for recipes that use naturally gluten-free thickeners, such as pureed vegetables or cornstarch, arrowroot or even mashed potatoes.

A Perfect Gluten-free Pie
What’s Thanksgiving without pumpkin pie? Or pecan…or even apple for that matter? But the flour in the pie crust is problematic for those who eat gluten-free. Thankfully, there are a number of alternative grain-free flours available that work well in pie crust recipes. Many recipes require combining gluten-free flour with potato starch, but you can usually find gluten-free ready-prepared pie crusts in the freezer aisle of your grocery store this time of year.

Smoked and Spiced Pecans
If you’re looking for a gluten-free snack that smells and tastes like Thanksgiving, try making your own smoked and spiced pecans. Search for recipes to make “smokehouse nuts” and you’ll find that, in usually less than an hour, you can make a delicious snack or appetizer that doesn’t call for gluten.

Post Author

Author

Katie Ferraro

Contributor

Katie Ferraro, MPH, RDN, CDE is a consultant dietitian and diabetes educator specializing in nutrition communications and family feeding. As a mom to 5 small children and creator of the popular blog The Fortified Family, Katie believes that good food fuels strong families. You can read more of her work at www.fortifiedfam.com

What Is the Cause of Muscle Cramps?

by Len Kravitz, PhD and Rogelio Realzola on Oct 22, 2019

A discussion of the popular theories on what causes muscle cramps.

Muscle cramps can stop athletes in their tracks. Although they usually self-extinguish within seconds or minutes, the abrupt, harsh, involuntary muscle contractions can cause mild-to-severe agony and immobility, often accompanied by knotting of the affected muscle (Minetto et al. 2013). And cramps are common; 50%–60% of healthy people suffer muscle cramps during exercise, sleep or pregnancy or after vigorous physical exertion (Giuriato et al. 2018). There is no gender difference with skeletal muscle cramps, but they appear to occur more often in endurance athletes and in the elderly (Naylor & Young 1994).

During endurance exercise, muscle cramps correlate with the length and intensity of workouts. Fitness pros and clients frequently talk about muscle cramps, but until recently, little has been known about their actual physiology.

Types of Muscle Cramps

Giuriato et al. categorized muscle cramps into three groups:

    1. Nocturnal cramps occur during sleep without any clear trigger.
    1. Pathological cramps are a consequence of having diabetes, nerve dysfunctions or metabolic disorders.
  1. Exercise-associated muscle cramps occur during or after exertion. The first scientific confirmation of these types of cramps dates to 1908, when they were described in miners working in hot and humid conditions.

Muscle Cramp Risk Factors

With marathon runners, research has found certain risks associated with the occurrence of a muscle cramp (Schwellnus, Derman & Noakes 1997). These risks include a longer history of running, advanced age, higher body mass index, shorter daily stretching time, irregular stretching habits and a family history of cramping. Schwellnus, Derman & Noakes report that the two most important observations from the research are that exercise-associated cramps for marathoners are muscle fatigue (linked to longer runs) and poor stretching habits.

Early Theories About Muscle Cramp Causes

Theories on the Cause of muscle cramps
Early theories on the source of muscle cramps focused on electrolytes, dehydration and the environment.

Schwellnus, Derman & Noakes analyzed three early theories on the causes of exercise-associated muscle cramps.

SERUM ELECTROLYTE THEORY

Blood plasma contains electrolytes, such as sodium, potassium, chloride, bicarbonate, calcium and phosphate. Although electrolyte depletion is often blamed for causing cramps, there currently is no solid explanation of how low serum electrolyte concentrations can result in the condition. Schwellnus, Derman & Noakes pointed to two studies that measured serum electrolyte concentrations in endurance runners at prerace, immediate postrace and at 60-minute postexercise recovery. Neither study found a connection between postrace recovery, muscle cramps and changes in serum electrolyte concentrations.

DEHYDRATION THEORY

In the past, studies have suggested treating muscle cramps in workers and firefighters with fluids and electrolytes. But those studies did not measure hydration. More recent studies that have estimated blood volume and plasma volume do not support the theory that dehydration has a direct link to exercise-associated cramps.

ENVIRONMENTAL THEORY

This theory sprang from the condition referred to as “heat cramps.” While exercising in a hot, humid environment may be correlated with the development of muscle cramps, no evidence shows cramps are linked to an increase in core body temperature.

Current Theory on Muscle Cramps

The newest concept of muscle cramps is a neuromuscular theory (Giuriato et al. 2018). This theory has evolved to point to two origins: a central (spinal column) and a peripheral (neuromuscular junction).

The central or spinal origin theory suggests that the involuntary contraction of a muscle occurs when nerve messages to the spinal column are altered, perhaps due to muscle fatigue (see “The Neuromuscular Theory of Skeletal Muscle Cramps,” below). This results in an imbalance of excitatory (from muscle spindles) and inhibitory (from Golgi tendon organs) spinal messages to muscles (see “What are Muscle Spindles and Golgi Tendon Organs?,” below). This neural signaling imbalance leads to enhanced muscle cell excitability and cramping.

With the peripheral origin theory, scientists suggest there is abnormal excitation of the motor nerves terminal branches to the muscle, causing cramping.

The scientific evidence of a neuromuscular theory is mounting. The research appears to show that, in some cases, fatigued muscle can’t fully relax. This condition leads to an imbalance between excitatory signals and inhibitory messages to the muscle. So the most recent research appears to support the central origin theory of the muscle cramp (Giuriato et al. 2018; Scwellnus, Derman & Noakes 1997).

For information on the neuromuscular theory of skeletal muscle cramps; muscle spindles and Golgi tendon organs and muscle cramp prevention, see “Ouch! What Causes Muscle Cramps” from the October 2019 print edition of Fitness Journal. If you cannot access the full article and would like to, please contact the IDEA Inspired Service Team at 800-999-4332, ext. 7.

Carbohydrates: Why are They So Confusing?

by Nancy Clark
on

 

Carbohydrates can be a source of confusion for athletes and fitness enthusiasts alike, many of whom believe they should avoid pasta, bagels, juice, bananas, sugar… the list goes on. In reality, people who are physically inactive whose bodies do not readily metabolize carbohydrates may need to take a different approach to consuming carbohydrates compared to regular exercisers and athletes. Here’s some information to help resolve carbohydrate confusion.

What do you actually mean when you say “carbs”?

  • Carbohydrates include both sugars and starches; they are biochemically similar. For example, an unripe banana (or any fruit) is starchy. As it ripens, it becomes sweeter; the starch converts into sugar. In comparison, peas (and other vegetables) are sweet when young and their sugar converts into starch as they mature.
  • All forms of sugar and starch digest into the simple sugar glucose. Glucose travels in the blood and, with the help of insulin, is taken up for fuel by the muscles to fuel your workouts. Fit bodies handle carbohydrates better than unfit bodies.

Are carbs bad for you?

  • Regarding health, some carbs are better for you than others because some offer more nutrients than others. Even though refined sugar adds “empty calories” to a sports diet, you need not eat a sugar-free diet to have a healthy diet. A physically fit, healthy person’s menu can accommodate 10% of calories from refined sugar (World Health Organization’s guidelines). Yet, if you frequently consume sweets plus sports drinks, gels and sports candies, you can easily consume more than 250 to 350 calories (10% of calories) from refined sugar.
  • The fear-mongering terms of unhealthy, toxic and poisonous that surround conversations regarding carbohydrate are simply unscientific. People who lack knowledge about physiology accept this disease-mongering, anti-sugar rhetoric. But the fact is no one food is healthy or unhealthy.

Are carbs fattening?

  • Despite popular belief, carbohydrates are not inherently fattening. Excess calories are fattening.

What about high-fructose corn syrup?

  • High-fructose corn syrup (HFCS) is less evil than is often portrayed by the media. HFCS is a double molecule comprised of 45% glucose, 55% fructose—the same as honey and similar to white sugar (50% glucose, 50% fructose).
  • The negative hype about HFCS applies primarily to people who consume excessive calories of sweets, soda, candies and processed foods sweetened with HFCS. While no one needs excessive, lack-luster calories that could be better spent on nutrient-rich fruits, veggie and whole grains, does an athlete really need to fret about a few calories of HFCS in ketchup?

What about sugar “crashes”?

  • The most common reason for “sugar crashes” (hypoglycemia) among athletes relates to running out of fuel. The shakiness and sweats are because the athlete did not eat enough food to maintain normal blood glucose levels and the brain is now demanding sugar. One marathoner, who thought the 100-calorie gel he consumed at mile 16 caused him to “crash,” more likely needed 200 to 300 calories to meet his energy needs.
  • A sharp rise in blood sugar that may occur after eating sugary foods is not pathological, and has more to do with the efficiency of the muscles and liver in their ability to take up the sugar. Exercise enhances the transport of sugar from your blood into your muscles with far less insulin than needed by the body of a person who is physically inactive.

Summary

For physically active, fit people who are at lower risk for heart disease, diabetes and obesity, sugar and carbs are not toxic, and may be a helpful way to enhance athletic performance. The one-size-diet does not fit all.

No one is suggesting that you or your clients should eat more sugar, but rather understand that athletes and people who are regularly physically active can embrace a way of eating that includes an appropriate balance of carbohydrate (sugars and starches) in each meal. Strive for a healthy eating pattern that includes 85-90% quality foods and 10-15% whatever. Some days, whatever might be an apple; other days, it might be a slice of apple pie.

Want to help your clients make healthier, long-lasting food choices? Become an ACE Fitness Nutrition Specialist

 

Carbohydrates can be a source of confusion for athletes and fitness enthusiasts alike, many of whom believe they should avoid pasta, bagels, juice, bananas, sugar… the list goes on. In reality, people who are physically inactive whose bodies do not readily metabolize carbohydrates may need to take a different approach to consuming carbohydrates compared to regular exercisers and athletes. Here’s some information to help resolve carbohydrate confusion.

What do you actually mean when you say “carbs”?

  • Carbohydrates include both sugars and starches; they are biochemically similar. For example, an unripe banana (or any fruit) is starchy. As it ripens, it becomes sweeter; the starch converts into sugar. In comparison, peas (and other vegetables) are sweet when young and their sugar converts into starch as they mature.
  • All forms of sugar and starch digest into the simple sugar glucose. Glucose travels in the blood and, with the help of insulin, is taken up for fuel by the muscles to fuel your workouts. Fit bodies handle carbohydrates better than unfit bodies.

Are carbs bad for you?

  • Regarding health, some carbs are better for you than others because some offer more nutrients than others. Even though refined sugar adds “empty calories” to a sports diet, you need not eat a sugar-free diet to have a healthy diet. A physically fit, healthy person’s menu can accommodate 10% of calories from refined sugar (World Health Organization’s guidelines). Yet, if you frequently consume sweets plus sports drinks, gels and sports candies, you can easily consume more than 250 to 350 calories (10% of calories) from refined sugar.
  • The fear-mongering terms of unhealthy, toxic and poisonous that surround conversations regarding carbohydrate are simply unscientific. People who lack knowledge about physiology accept this disease-mongering, anti-sugar rhetoric. But the fact is no one food is healthy or unhealthy.

Are carbs fattening?

  • Despite popular belief, carbohydrates are not inherently fattening. Excess calories are fattening.

What about high-fructose corn syrup?

  • High-fructose corn syrup (HFCS) is less evil than is often portrayed by the media. HFCS is a double molecule comprised of 45% glucose, 55% fructose—the same as honey and similar to white sugar (50% glucose, 50% fructose).
  • The negative hype about HFCS applies primarily to people who consume excessive calories of sweets, soda, candies and processed foods sweetened with HFCS. While no one needs excessive, lack-luster calories that could be better spent on nutrient-rich fruits, veggie and whole grains, does an athlete really need to fret about a few calories of HFCS in ketchup?

What about sugar “crashes”?

  • The most common reason for “sugar crashes” (hypoglycemia) among athletes relates to running out of fuel. The shakiness and sweats are because the athlete did not eat enough food to maintain normal blood glucose levels and the brain is now demanding sugar. One marathoner, who thought the 100-calorie gel he consumed at mile 16 caused him to “crash,” more likely needed 200 to 300 calories to meet his energy needs.
  • A sharp rise in blood sugar that may occur after eating sugary foods is not pathological, and has more to do with the efficiency of the muscles and liver in their ability to take up the sugar. Exercise enhances the transport of sugar from your blood into your muscles with far less insulin than needed by the body of a person who is physically inactive.

Summary

For physically active, fit people who are at lower risk for heart disease, diabetes and obesity, sugar and carbs are not toxic, and may be a helpful way to enhance athletic performance. The one-size-diet does not fit all.

No one is suggesting that you or your clients should eat more sugar, but rather understand that athletes and people who are regularly physically active can embrace a way of eating that includes an appropriate balance of carbohydrate (sugars and starches) in each meal. Strive for a healthy eating pattern that includes 85-90% quality foods and 10-15% whatever. Some days, whatever might be an apple; other days, it might be a slice of apple pie.

 

The REAL Scoop on Protein Powders

by Matthew Kadey, MS, RD on Sep 06, 2019

Research suggests more protein foods and less powder will balance training needs.

Protein powders, especially the whey variety, have long been glorified in fitness circles for their muscle-building benefits. “Pump some iron and chug back a protein shake” is a preferred muscle-making formula. But research published in the journal Nature Metabolism, led by scientists from the University of Sydney, suggests that while the essential branched-chain amino acids (BCAAs) leucine, isoleucine and valine—found in high amounts in certain protein powders—can indeed help muscles recover and grow in response to training, excessive consumption of BCAAs may have unwanted side effects if taken at the expense of other amino acids from additional protein sources.

For instance, supplementing with high doses of BCAAs leads to high levels in the blood, potentially triggering competition with another amino acid, tryptophan, for transport to the brain. This can negatively affect mood, as tryptophan is a precursor for the feel-good hormone serotonin. Lower brain levels of serotonin can also stimulate appetite, leading to possible excess consumption of calories and, in the end, weight gain.

The take-home message is that it’s fine to include a scoop of whey protein in your daily diet to support training needs, but it’s best to eat a wide range of protein foods—including those from plant sources like legumes—to get a better balance of amino acids.