Low physical activity increases risk of bladder, kidney cancer

most of us know that physical activity is good for us. But a new study shows that a chronic lack of physical activity can drastically increase the chance of developing cancer in the bladder and kidneys, and it suggests that engaging in more physical activity may reduce this risk.

The Centers for Disease Control and Prevention (CDC) report that, every year, almost 57,000 adults have kidney and renal pelvis cancers in the United States. Additionally, almost 14,000 people per year die from these cancers.

Bladder cancer is also widespread. According to the CDC, around 71,000 U.S. individuals developed bladder cancer in 2013, and almost 16,000 people died as a result.

A team of researchers at the Roswell Park Cancer Institute in Buffalo, NY, set out to examine the link between leading a sedentary lifestyle and the risk of developing kidney or bladder cancer.

The findings were published in the journal Cancer Epidemiology.

The researchers were led by Dr. Kirsten Moysich, distinguished professor of oncology in the Departments of Cancer Prevention and Control and Immunology at Roswell Park, and Rikki Cannioto, assistant professor of oncology also in the Department of Cancer Prevention and Control at Roswell Park.

Drs. Moysich and Cannioto, along with their colleagues, analyzed 160 people with renal (kidney) cancer, 208 bladder cancer patients, and 766 healthy controls.

Participants were asked to report on their levels of physical activity - namely, whether or not they took part in any regular or weekly recreational physical activity throughout the course of their lives. Those who said that they had never done so were classified as "physically inactive."

The researchers used unconditional multivariable logistic regression methods to calculate the odds of developing renal and bladder cancer.

Inactivity increases kidney and bladder cancer risks by up to 77 percent

Overall, the authors found "evidence of a positive association between renal and bladder cancer with lifetime recreational physical inactivity."

Specifically, they found that those who were physically inactive were 77 percent more likely to develop renal cancer and 73 percent more likely to develop cancer of the bladder.

A similar risk was found among people with obesity and people with a normal body weight - that is, having a body mass index (BMI) of below 30. This suggests that leading a sedentary lifestyle is an independent factor that influences bladder and renal cancer risk independently of obesity.

This study adds to previous data that have shown the same correlation. Former studies have also indicated a link between chronic physical inactivity and an increased risk of ovarian and cervical cancer.

However, the authors concede that additional, larger-scale, prospective studies are needed to consolidate the findings.

Dr. Moysich comments on the results and urges people to engage in a simple, moderate form of physical activity:

"We hope that findings like ours will motivate inactive people to engage in some form of physical activity. You don't have to run marathons to reduce your cancer risk, but you have to do something - even small adjustments like taking the stairs instead of the elevator, walking around the block a couple of times on your lunch hour, or parking the car far away from the store when you go to the supermarket."

Dr. Cannioto also weighs in on the results, saying that the "findings underscore how important it is to maintain a healthy lifestyle, including getting and staying active. The Department of Health and Human Services recommends 150 minutes each week of moderate physical activity or 75 minutes each week of vigorous physical activity as a way to generate significant, lasting health benefits."

Picking the Perfect Protein

Protein is a critical component to muscle growth, maintenance and muscle repair and recovery, and it has a tremendous impact on strength and performance as well. To build muscle, it is essential that proper amounts of high-quality protein be consumed at the proper times, but it can be hard to choke down enough whole foods to fuel your goals. That’s where protein powder comes in. The good news is, there are plenty of choices for you. The bad news is, it can be overwhelming to figure out which one you should be taking. Here are some guidelines to help you pick the perfect protein for your goals.

The Power of Protein

Proteins are chains of amino acids that provide the substrates needed to build muscle and support metabolism. The amino acids in proteins also provide important biological signals for growth and recovery after bouts of heavy exercise or sports performances.

Protein supplements represent the most scientifically supported and effective muscle-building products on the market. This has led to the development of numerous different protein supplements formulated from one or more source proteins. Like most things in life, different sources of protein have strengths and weaknesses, but to get the best bang for your buck, there are a few things that must be considered. We provide you with a report card on the top five protein sources available today, evaluating and describing each one in several fundamental groupings. Consider these five important categories when choosing the right protein source(s) for the job.

PROTEIN SOURCE:

Whey Protein Isolate

OVERALL SCORE: A

Whey protein isolate represents one of the purest of all protein products on the market, with purity upward of 90 percent. Furthermore, pure WPI contains negligible amounts of fat and lactose, so it is great for those who are dieting or lactose intolerant. WPI is absorbed relatively quickly, which promotes robust and rapid increases in blood amino-acid levels and protein synthesis.

Amino-Acid Profile (A+): WPI contains an abundance of all eight essential amino acids, including exceptionally high levels of branched-chain amino acids and the highest levels of leucine among protein sources. Leucine is the primary BCAA necessary to turn on protein synthesis for muscle building.

Preworkout (A+): WPI’s absorption rate makes it ideal as a preworkout supplement. Taking as little as 20 grams before working out will ensure an abundance of important BCAAs are supplied throughout your training session, sparing hard-earned muscle (especially when dieting).

Postworkout (A+): Studies show that immediately after a bout of resistance training, the rate at which amino acids enter the blood is directly related to the level of anabolism in the body. Whey also boosts anabolic insulin better than other protein sources, enabling greater shuttling of glycogen and nutrients into fatigued muscle, promoting faster and greater recovery.

Between Meals (A+): WPI’s bioavailability is unrivaled by any protein source. This ensures every gram of protein participates in recovery and muscle building. Its relatively rapid absorption profile minimizes fullness and bloating, guaranteeing your muscle needs are met throughout the day.

Before Bed (C): The amino acids in WPI are absorbed at a rate of about eight to 10 grams per hour. So if you consume 40 grams before bed, you will be feeding your muscle for about four hours while you sleep. This isn’t bad, but micellar casein is better.

PROTEIN SOURCE:

Whey Protein Hydrolysate

OVERALL SCORE: B+

Whey protein hydrolysate is processed from WPI or whey protein concentrate by predigestion, which entails using enzymes to break down (hydrolyze) the protein, resulting in the production of peptide fractions (short chains of amino acids). These fractions are low molecular weight and absorb into the bloodstream quickly. Because of rapid absorption, WPH supplements drive water into muscle cells (cell volumizing), speeds recovery and signals for increased anabolic drive. Just remember that the hydrolyzing process is costly, so WPH products tend to be more expensive than other sources.

Amino-Acid Profile (A+): Enzymatic predigestion retains the superior amino-acid profile of the WPI or WPC starting product.

Preworkout (A+): The moderate absorption profile of WPH makes this a great choice before training. Studies have shown that sustaining high levels of blood amino acids while working out promotes greater muscle growth and faster recovery.

Postworkout (A+): WPH absorbs faster than any other source of protein. Since it is predigested, you will note very little stomach discomfort or bloating, which means you can eat a healthy meal soon after ingestion.

Between Meals (C): During this time, you want a protein that will sustain amino-acid delivery for two to four hours and WPH’s absorption rate is too fast.

Before Bed (D): WPH is known for its fast rate of absorption, which is the opposite of what you want from a protein shake before bed. Stick with slow-absorbing proteins (like micellar casein) for best effect.

PROTEIN SOURCE:

Whey Protein Concentrate 

OVERALL SCORE: B+

Compared to WPI and WPH, whey protein concentrate is relatively impure. The impurities in WPC are mostly from lactose and fat, making this product undesirable for those who are dieting and/or lactose intolerant. Notably, WPC is the starting material for most whey protein supplements, so you can still reap most of the muscle-building benefits of WPI and WPH. However, since WPC does not require the same level of processing, it is more affordable. Just remember, due to impurities, scoop for scoop you get less protein.

Amino-Acid Profile (A+): Since WPC is the starting material for other forms of whey, it has a comparable amino-acid profile to WPH and WPI. However, less processing means that the whey will retain more of its native structure and added health benefits.

Preworkout (B): WPC has a medium absorption rate, which is good for a preworkout protein supplement. The fat and lactose in WPC may cause bloating or stomach discomfort when taken before physical exertion. Postworkout (A): WPC has a medium absorption rate, making it a very good postworkout protein source.

Between Meals (A): WPC is a great product to be taken between meals. The extra calories in this supplement provide excellent nourishment for ectomorphs (i.e., skinny and lean people) and those who are bulking up.

Before Bed (B): With its medium absorption rate, a WPC shake is a decent choice before bed. There’s a caveat: Extra calories from fat and lactose in WPC are not ideal right before sleeping.

PROTEIN SOURCE:

Micellar Casein 

OVERALL SCORE: A

Casein is the most abundant protein found in cow’s milk. Micellar casein has the unique ability to form a gel in the stomach, slowing absorption and making it a sustained supplier of amino acids.

Amino-Acid Profile (A+): Micellar casein protein has a robust amino-acid profile. A good micellar casein product will be produced by advanced microfiltration techniques, which preserves the many subfractions and growth factors known to contribute to its anti-catabolic properties.

Preworkout (D): Micellar casein has the slowest absorption rate of all protein products rendering it a less effective choice compared to whey protein products.

Postworkout (D): Again, the remarkably slow absorption of micellar casein makes it a mediocre postworkout choice compared to whey protein.

Between Meals (A+): The slow absorption and high bioavailability of micellar casein provides protection against catabolism between meals, especially when you won’t get a chance to eat for several hours.

Before Bed (A+): This is when micellar casein outshines the rest, making it the No. 1 protein supplement at that time. Drinking just 30 grams of micellar casein has been shown scientifically to promote a seven-hour sustained plateau in blood amino acids, leading to the highest muscle nitrogen retention and utilization in its class. In one study, the slow and sustained absorption of this protein was shown to reduce catabolism by 34 percent for seven hours after ingestion.

PROTEIN SOURCE:

Egg Protein (Albumin)

OVERALL SCORE: C+

Before we knew about whey protein supplements, eggs were the benchmark by which all other proteins were compared. Egg protein supplements are very low in fat and contain an abundance of amino acids. Egg protein isolate is well tolerated in moderation and digests completely, but can cause bloating and gas if used in excess.

Amino-Acid Profile (B): Eggs carry a good amino-acid profile that contains all of the essential and sulfur-bound amino acids. Egg protein used to be the best product available but whey products offer much better amino-acid profiles (e.g., high-grade whey protein contains more leucine than egg albumin).

Preworkout (B): Egg isolates digest at fast to medium speed, so they elevate amino acids at a moderate rate. Studies show that 25 to 30 grams of egg albumin will elevate blood amino acids for about two to three hours, which is ideal for preworkout use. However, egg albumin may cause bloating and gas, which may hinder training.

Postworkout (D): Compared to WPI and WPH, egg protein is just passable as a postworkout protein. This is mainly due to the superior amino-acid profile found in whey products.

Between Meals (A+): Egg protein is an ideal supplement for between meals. It is affordable and provides an adequate source of protein with ideal digestion time, nicely bridging the gap from meal to meal.

Before Bed (D): With its moderate absorption rate, egg albumin will not provide optimal protein nutrition throughout the night.

Protein Blends: Practical Choices?

Protein powder blends are becoming more popular. They are formulated using proteins from many sources with different absorption profiles. The rationale for such products is to deliver a single protein supplement that provides all the unique advantages of fast-, medium- and slow-digesting protein sources. 

In the last few years there has been a handful of research suggesting that blended protein supplements have a unique ability to raise and sustain blood amino-acid levels better than whey protein isolate alone. If you are looking for a protein blend, the best products contain fast-digesting whey protein hydrolysates and isolates, as well as slower-digesting milk protein isolates and/or micellar casein.

1) With an array of proteins with differing absorption rates, they are ideal for someone who wants a “well-rounded” protein supplement for any time of the day.

2) They are great for people on a budget or just starting out, as they save buying multiple protein supplements for different times of the day.

3) With a broad spectrum of absorption and robust amino-acid profiles, they are an ideal protein boost for those who don’t have the opportunity to take time out to eat every two or three hours.

Benefits of medical marijuana for treatment of epilepsy examined

Although cannabis had been used for many centuries for treatment of seizure disorders, medical use became prohibited in the 20th century. However, with the loosening of laws regarding medical marijuana, research and clinical use of marijuana-derived substances are increasing. This has prompted the editors of Epilepsy & Behavior to produce a special issue that presents an in-depth assessment of the potential of cannabinoids for the effective treatment of epilepsy. Cannabinoids are components of the cannabis plant.

Guest Editors Jerzy Szaflarski, MD, PhD, Director of the Epilepsy Center, University of Alabama at Birmingham, and Orrin Devinsky, MD, Director, Epilepsy Center, New York University Langone Medical Center, New York, comment that, "There is an enormous dissociation between the widespread use of cannabis-based therapies to treat diverse epilepsies and our understanding about the efficacy and safety of different cannabinoids in treating different epilepsy syndromes." Because much of the political pressure to allow for medical marijuana use came from patients and lay groups, the goal of this special issue is "to evaluate the concerns and gaps in cannabinoid knowledge and medical education, and to create a curriculum as a first step in building a broader Education Roadmap."

This special issue provides an overview for general neurologists and epileptologists, including historical aspects of cannabis use for epilepsy, overview of cannabis botany, general aspects of the endocannabinoid system as it pertains to epilepsy, pharmacology of cannabinoids, available anecdotal and clinical trial data of cannabinoid use for the treatment of epilepsy, safety data, discussion of possible effects of cannabinoids on the brain including neuroimaging data, and the legal aspects of cannabis production, distribution, and use for the treatment of epilepsy.

Raphael Mechoulam, PhD, Head of the School of Pharmacy and Director of the Institute for Drug Research at Hebrew University, provides an insightful historical perspective. He notes that non-psychoactive cannabidiol (CBD) is officially approved for the treatment of intractable pediatric epilepsy in Israel, but it took over 35 years to conduct the studies and obtain the results. "I expect that over the next decade we shall see major advances both in the medical-scientific and the treatment aspects of epilepsy with the help of CBD and related cannabinoids," explains Dr. Mechoulam.

To move a plant-based drug from research studies to clinical use is a particular challenge for pharmaceutical companies. Suman Chandra, PhD, Senior Research Scientist at the University of Mississippi, and co-authors review how the United States and United Kingdom have addressed the problem of securing uniform supplies of medically pure and potent cannabinoids. They review cultivation and processing of marijuana at two institutions with extensive experience, GW Pharmaceuticals in the U.K. and the University of Mississippi in the U.S.

Because both media coverage of cannabis use in epilepsy and inconsistent classification of medical marijuana usage in different U.S. states have short-circuited the rigorous scientific protocols of the U.S. Food and Drug Administration (FDA), quality validation may be lacking. Dustin Sulak, DO, Integr8 Health (Falmouth, ME) and co-investigators review how "artisanal" cannabis preparations, not subject to state regulatory controls, are being used in Washington and California. They also relate four case studies of pediatric epilepsy patients that illustrate the complexities of treatment due to variability of these preparations.

As an example of how interest in medical use of cannabis can be driven by social media and word-of-mouth, Anastasia S. Suraev, The Lambert Initiative for Cannabinoid Therapeutics, The University of Sydney, and co-authors surveyed the Australian epilepsy community. This online survey was promoted by Epilepsy Action Australia, a national non-profit organization that provides education and services to people with epilepsy and their families. There were 976 responses, about 60% from adults with epilepsy and the remainder from children with epilepsy. Overall, 14% reported currently using or having previously used cannabis products to treat epilepsy. Of the 389 children with epilepsy included in the survey, 13% had a reported history of cannabis product use for epilepsy. Of these, 71% of parents/guardians rated cannabis products as successful in helping them manage their child's seizures. Furthermore, 51% of parents/guardians reported reduced use of anti-epileptic drugs by their child after commencing use of cannabis products.

Although cannabis is currently legal for medical purposes in half of the states and another seventeen states allow products that are high in cannabidiol (CBD) and low in THC (tetrahydrocannabinol) for medical use, none of these products has been approved by the FDA. Alice Mead, JD, LLM, GW Pharmaceuticals, Inc. (Carlsbad, CA) provides an overview of the legal aspects of cannabis and cannabidiol, including cultivation, manufacture, distribution, and use for medical purposes.

"We hope these articles help stimulate greater understanding and more importantly, stimulate more studies to scientifically define the potential benefits and harms of cannabis-based therapies for epilepsy," note Dr. Szaflarski and Dr. Devinsky. "We need to develop a curriculum to address the rapidly changing scientific and regulatory landscape surrounding the medical use of cannabis and cannabinoids."

The special issue can be found online at: http://www.epilepsybehavior.com/issue/S1525-5050(17)X0007-3

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Recommended daily protein intake too low for the elderly

The minimum protein requirement for healthy adults has been set almost 15 years ago but there is a growing body of evidence that this recommended dietary allowance (RDA) is not sufficient for older persons.

You can find the recommended dietary allowance (RDA) on the nutrition labels of all your processed food. Food manufacturers are obliged to list the nutritional value of their products, and therefore must mention the percent daily value of the RDA their product meets for certain nutrients.

These RDA guidelines are put together by the Food and Nutrition Board of the National Academy of Sciences' Institute of Medicine. They inform you how much of a specific nutrient your body minimally needs every day. They are set to meet the requirements of 97.5% of the healthy individuals older than 19 years.

The RDA you will find on the nutrition labels on your food, however, were set in 1968, and the ones used by researchers and professionals were set in 2003. A recent review published in Frontiers in Nutrition points out that both these values do not do justice to the protein needs of the elderly and critically ill.

"A big disservice is being done. The prescribed 0.8 g/kg/day just isn't enough protein for the elderly and people with a clinical condition. This shouldn't be communicated as what is 'allowed' or even 'recommended' to eat.," author Stuart Phillips of McMaster University in Canada explains.

In his review, he points out that the quality of proteins should be considered when setting the RDA guidelines and recommending protein supplements. He argues that there should be a stronger focus on leucine; an indispensable amino acid and building block for proteins. The elderly have a higher need for leucine to build muscle proteins, and milk-based proteins (e.g. milk and whey) are a good source for this.

Moreover, it may be highly beneficial for the critically ill patients that rapidly lose lean body mass (i.e. the body weight minus body fat) to increase their protein intake. Again, elderly ill patients would benefit the most from this. "I think it's clear we need some longer-term clinical trials with older people on higher protein intakes. These trials need to consist of around 400 -- 500 people.," Phillips argues.

He is not the first researcher to challenge the current protein RDA, and hopes his message does not fall on deaf ears. That is also why he chose to publish Open Access: "I love to publish work that everyone can read. The days of publishing a paper that only people in academic institutions can read are over. I think it is essential that everyone and not only your scientific colleagues can read the work we do."

At his own dinner table, Phillips also puts the focus on proteins. "But not at the expense of other macronutrients. I enjoy a variety of foods, and the only thing I specifically focus on is limiting my intake of sugar and refined carbohydrates. But of course, given the benefits of proteins, they are a big part of what I think about when planning my meals."

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Fiber-rich diet linked to lowered risk of painful knee osteoarthritis

A fibre-rich diet is linked to a lowered risk of painful knee osteoarthritis, finds the first study of its kind, published online in the Annals of the Rheumatic Diseases.

The findings, which draw on two different long term studies, are broadly in line with the other reported health benefits of a fibre-rich diet. These include reductions in blood pressure, weight, and systemic inflammation, and improved blood glucose control.

The researchers mined data from two US studies in a bid to find out if dietary fibre might have any bearing on the risks of x-ray evidence of knee osteoarthritis, symptomatic knee osteoarthritis (x-ray evidence and symptoms, such as pain and stiffness), and worsening knee pain.

The first of these studies was the Osteoarthritis Initiative (OAI). This has been tracking the health of nearly 5000 US men and women with, or at risk of, osteoarthritis since 2004-6 (average age 61), to pinpoint potential risk factors for the condition.

The second was part of the Framingham Offspring cohort study, which has been tracking the health of more than 1200 adult children of the original Framingham Heart Study and their partners since 1971. For the current study, results are based on data first taken between 1993-4, when participants were 54, on average, up to 2002-5.

For both studies, dietary fibre intake was measured using Food Frequency Questionnaire responses. It averaged out at around 15 g daily in the OAI, and 19 g daily in the Framingham Offspring, study.

Information on symptoms and x-ray evidence were collected every year for four years in the OAI and assessed after 9 years in the Framingham Offspring study. Data were also gathered on potentially influential factors, such as knee injury/surgery, medication, and lifestyle, including tobacco and alcohol use and physical exercise.

At the end of 4 years, among the 4051 participants in the OAI with complete data on dietary fibre intake, 869 knees were symptomatic; 152 displayed x-ray evidence of osteoarthritis; and pain had worsened in 1964.

After an average of 9 years, among 971 participants in the Framingham Offspring study with complete dietary fibre data, 143 knees were symptomatic and 175 displayed x-ray evidence of osteoarthritis.

Analysis of the data showed that eating more fibre was associated with a lower risk of painful knee osteoarthritis. Compared with the lowest intake (bottom 25 per cent of participants), the highest intake (top 25 per cent) was associated with a 30 per cent lower risk in the OAI and a 61 per cent lower risk in the Framingham study. But it was not associated with x-ray evidence of knee osteoarthritis.

Additionally, among the OAI participants, eating more fibre in general, and a high cereal fibre intake, were associated with a significantly lower risk of worsening knee pain.

These findings held true, regardless of other potentially influential factors.

This is an observational study, so no firm conclusions can be drawn about cause and effect. Nevertheless, the researchers say: "These data demonstrate a consistent protective association between total fibre intake and symptom-related knee [osteoarthritis] in two study populations with careful adjustment for potential confounders."

And they point to other evidence suggesting that a fibre-rich diet is associated with several health benefits, many of which are relevant to osteoarthritis.

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Optimum Rest for Optimum Gains

Getting enough rest after weight training is essential for optimal muscle growth and performance. Unfortunately, many get insufficient rest because they simply disregard the fact that weightlifting breaks down muscle tissue, creating the requirement for adequate rest to fully recuperate. In addition, insufficient rest may occur when alterations in training are implemented to boost training stimulus without sufficiently addressing the increased requirements for greater rest. As a result of inadequate rest from either of the aforementioned reasons, complete muscle recovery may not occur and performance in the weight room can eventually decline and even deteriorate into the state of overtraining. In fact, inadequate rest between workouts can raise the chance for injury.

 Beginners Need More Rest

The necessary amount of rest required between workouts for full recovery is heavily influenced by many different factors, with one of the more pertinent influences being the subject’s level of conditioning or training experience. In fact, less-experienced lifters require more days off between workouts and should progressively decrease the amount of rest days between workouts as they become more fit. To start, novice weightlifters should begin a program with only two to three strength-training sessions per week, with at least one rest day between training days, as there are numerous resistance-training studies that have shown that this training frequency was initially effective for strength gains in untrained individuals.1,2 However, it has also been shown that untrained subjects did not fully recover all of their strength two days after a lower-body workout consisting of five sets of 10 repetitions on the leg press3, suggesting that lesser-trained individuals may actually need recovery periods greater than one day, depending on the type of exercise performed. Taken together, the best approach for beginners entails lifting sessions completed on nonconsecutive days while providing one to two days of exercise-free rest days between workouts. Yet keep in mind that some individuals might require additional rest days, and may want to begin with only two workouts per week on nonconsecutive days.

 More Advanced Lifters Require Less Rest

For the more experienced weightlifter, promoting continued muscle growth requires a gradual increase in exercise stimuli. While there are many parameters that can be altered to boost the training effect for advanced lifters, an increase in exercise frequency exemplifies a powerful way to accomplish this objective. This is primarily because increased training frequency encourages the use of split workout routines that maximize exercise volume without dangerously depleting recuperation time. For instance, although more advanced lifters usually exercise at a higher frequency of four to six days per week, split training protocols target different muscle groups on various days providing adequate rest of one to two days for each specific muscle group. In fact, studies have shown that training four to five days per week using a split protocol achieved better results than those who split-trained three days per week.4

 Sore Muscles Increase Rest Requirement

Exercise-induced muscle damage primarily occurs when performing a lift that your body is unaccustomed to, or when you crank up the training intensity by increasing the amount of weight lifted or the total number sets performed.5 In addition, more intense workouts incorporating weightlifting movements that focus on the negative contraction or eccentric component of the lift induce even greater muscle damage. This is primarily because the negative or eccentric phase of muscle contraction forcibly lengthens the muscle cell, generating more destructive forces on the muscle fiber and causing greater damage.

Greater muscle damage stimulates many different cellular and molecular mechanisms that cause the muscle cell to grow and become more powerful6, while also requiring longer rest periods between workouts for full recovery. The increased necessity for rest is due to the fact that lifting weights with sore muscles limits your ability perform in the weight room, and may lead to further anatomic and biochemical deficiencies within the muscle tissue that may ultimately cause overtraining and injury. In order to reduce extensive muscle soreness and avoid lengthy rest periods, slowly increase exercise intensity and utilize eccentric training techniques periodically for relatively short durations. This methodical approach should provide acceptable amounts of muscle soreness that will not require too much time out of the gym, while simultaneously supporting optimal muscle growth and strength.

 Extensive Rest Periods Increase Fast-Twitch Fiber Content

There are essentially three major types of muscle fiber that are generally segregated as follows: slow-twitch (type I), moderately fast-twitch (type IIA) and very fast-twitch (type IIX). The fibers are called “slow” and “fast” due to the relative rate at which they contract, with fast-twitch fibers contracting roughly four times faster than slow-twitch fibers7, giving the fast-twitch fiber a greater force-producing capacity as well. As a result, slow fibers are important for endurance activities such as long-distance running, whereas fast fibers are essential for power-based sports such as weightlifting, bodybuilding and football.

Interestingly, a study by Andersen et al.8 has shown that resistance training combined with substantial rest between workouts can shift one type of fast-twitch fiber to the other. In this study, the researchers demonstrate that muscle fibers exposed to extensive weight training initially decrease the number of very fast-twitch fibers from nine percent to two percent, converting them to the other fast-twitch fiber type. However, when the same subjects were exposed to long periods of rest, they surprisingly showed a relative increase in very fast-twitch fibers— increasing the amount of very fast-twitch fibers from nine percent to an average value of 18 percent at the end of the rest period, which also correlated to overall strength gains.

Although the mechanism underlying the increase in very fast-muscle fibers from long rest periods is unclear, some useful applications can still be drawn. For starters, in order to boost the relative amount of very fast fibers for improved muscle force production and muscle growth, the best training strategy appears to be heavy resistance training followed by an ample rest period leading up to the day of the contest or competition.

For most of Michael Rudolph’s career he has been engrossed in the exercise world as either an athlete (he played college football at Hofstra University), personal trainer or as a Research Scientist (he earned a B.Sc. in Exercise Science at Hofstra University and a Ph.D. in Biochemistry and Molecular Biology from Stony Brook University). After earning his Ph.D., Michael investigated the molecular biology of exercise as a fellow at Harvard Medical School and Columbia University for over eight years. That research contributed seminally to understanding the function of the incredibly important cellular energy sensor AMPK— leading to numerous publications in peer-reviewed journals including the journal Nature. Michael is currently a scientist working at the New York Structural Biology Center doing contract work for the Department of Defense on a project involving national security.

High levels of exercise linked to nine years of less aging at the cellular level

Despite their best efforts, no scientist has ever come close to stopping humans from aging. Even anti-aging creams can't stop Old Father Time.

But new research from Brigham Young University reveals you may be able to slow one type of aging -- the kind that happens inside your cells. As long as you're willing to sweat.

"Just because you're 40, doesn't mean you're 40 years old biologically," Tucker said. "We all know people that seem younger than their actual age. The more physically active we are, the less biological aging takes place in our bodies."

The study, published in the medical journal Preventive Medicine, finds that people who have consistently high levels of physical activity have significantly longer telomeres than those who have sedentary lifestyles, as well as those who are moderately active.

Telomeres are the protein endcaps of our chromosomes. They're like our biological clock and they're extremely correlated with age; each time a cell replicates, we lose a tiny bit of the endcaps. Therefore, the older we get, the shorter our telomeres.

Exercise science professor Larry Tucker found adults with high physical activity levels have telomeres with a biological aging advantage of nine years over those who are sedentary, and a seven-year advantage compared to those who are moderately active. To be highly active, women had to engage in 30 minutes of jogging per day (40 minutes for men), five days a week.

"If you want to see a real difference in slowing your biological aging, it appears that a little exercise won't cut it," Tucker said. "You have to work out regularly at high levels."

Tucker analyzed data from 5,823 adults who participated in the CDC's National Health and Nutrition Examination Survey, one of the few indexes that includes telomere length values for study subjects. The index also includes data for 62 activities participants might have engaged in over a 30-day window, which Tucker analyzed to calculate levels of physical activity.

His study found the shortest telomeres came from sedentary people -- they had 140 base pairs of DNA less at the end of their telomeres than highly active folks. Surprisingly, he also found there was no significant difference in telomere length between those with low or moderate physical activity and the sedentary people.

Although the exact mechanism for how exercise preserves telomeres is unknown, Tucker said it may be tied to inflammation and oxidative stress. Previous studies have shown telomere length is closely related to those two factors and it is known that exercise can suppress inflammation and oxidative stress over time.

"We know that regular physical activity helps to reduce mortality and prolong life, and now we know part of that advantage may be due to the preservation of telomeres," Tucker said.

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Journal Reference:

1. Larry A. Tucker. Physical activity and telomere length in U.S. men and women: An NHANES investigation. Preventive Medicine, 2017; 100: 145 DOI: 10.1016/j.ypmed.2017.04.027