All posts by Andrea Kirk

Iron Deficiency, Anemia and Athletic Performance

Iron deficiency may slow down athletes, impair training and just making working out harder than it needs to be.

The Iron part of anemia, iron deficiency and athletes

Iron is important for athletes as well as everyone else.   Iron is needed for formation of Hemoglobin.  Hemoglobin is the molecule in blood cells that transports oxygen through blood.  People who have low levels of red blood cells are said to be anemic.  Anemia can be caused by many different things.  This article, however, will focus on anemia caused by nutritional deficiency.

Crossfit sports anemia Iron deficiency
A crossfit athlete trains for the games. Is iron deficiency hurting her performance?

Iron deficiency can slow you down and make your workouts harder and more frustrating than they need to be.   People who are iron deficient (or anemic) don’t carry oxygen efficiently.  The heart has to work harder to get oxygen to tissues.  Low oxygen can also cause “poop out” (just too tired to continue the workout).  No need to mention this . . . but . . .   an iron deficient person is not likely to compete well either.  Anemia is most common in women of reproductive age. Recommended intake of iron is 8mg/day for men and post-menopausal women.  It is 18/mg/day for women who are menstruating.  Iron deficiency anemia (anemia not caused by blood loss, injury, illness of metabolic disorder) is highest among women of reproductive age.  It is uncommon in young men and boys and more common in people over 50.  About 7% of masters adults may have iron deficiency anemia. (Looker et al. 1997)

The athlete part of athletes iron and nutrition

There have been a number of studies of iron intake and exercise performance in animals and in people.  Performance related studies have looked at work performance, fatigue, endurance, oxygen use and heart rate (McClung & Murray-Kolb2013)   Iron supplementation has been associated with:

Anemia, Iron deficiency and Athletes
A crossfit athlete fatigues during the crossfit games. Fatigue increases risk of injury.
  • Increased maximal exercise performance
  • Increased VO2 max (maximal oxygen consumption
  • Lower heart rate
  • Less fatigue
  • More voluntary activity
  • Improved work performance
  • Improved performance on fitness tests
  • Increased energy expenditure

Intense training can lead to anemia.  The popular term for training-induced anemia is Sports Anemia.  Possible causes are intestinal bleeding, iron loss through perspiration, inflammation and a generally faster rate of body iron turnover.    Many athletes (especially older athletes) use ibuprofen to cope with muscle soreness and aches and pains from injuries.  Chronic use of aspirin and ibuprofen can increase risk of iron deficiency because they can cause stomach bleeding.

Iron deficiency can cause some cognitive problems too.  These include spatial ability, attention, memory, executive functioning and planning. These abilities are important in everyday life.  They are also abilities that are essential to training and competition.

The nutrition side of athletes, iron and nutrition

Iron-rich foods include:

  • red meat
  • fish
  • poultry
  • beans
  • dried fruit
  • whole grains
  • chard
  • spinach
  • molasses (black strap style)

Other nutritional deficiencies can also make you vulnerable to iron deficiency even if you are getting enough iron.  Vitamin C and Folate are important too.  Low vitamin B12 also increases risk of anemia. There are a lot of interactions among Vitamin C, Vitamin B12, and Folate that are still poorly understood.  High folate combined with low B12 increases the risk of anemia and risk of cognitive impairment in older people.  Normal B12 and High Folate, on the other hand, protect against anemia and cognitive problems (Morris et al. 2007).  Annoying that there no simple answers.  The best strategy seems to be to eat a varied diet

Take Away

Use pain relievers in moderation.  Consider an iron supplement and make sure you are getting enough folate and vitamin C.  Don’t over do iron intake.  There is no evidence that extra iron will help you if you don’t need it.  Too much iron can cause damage on its own.

 

Andrea Kirk, MSc. PhD is a toxicologist affiliated with the University of Texas at Arlington’s Department of Chemistry and Biochemistry and the University of North Texas Health Sciences Center‘s School of Public Health.  Dr. Kirk does research on human exposures to environmental contaminants and micro-nutrient intake and excretion.  She is also a former whitewater, dog-sledding, ice-climbing instructor and back-country ranger turned box rat.

 

Looker, A. (1997). Prevalence of Iron Deficiency in the United States JAMA: The Journal of the American Medical Association, 277 (12) DOI: 10.1001/jama.1997.03540360041028

Morris MS, Jacques PF, Rosenberg IH, & Selhub J (2007). Folate and vitamin B-12 status in relation to anemia, macrocytosis, and cognitive impairment in older Americans in the age of folic acid fortification. The American journal of clinical nutrition, 85 (1), 193-200 PMID: 17209196

McClung JP, & Murray-Kolb LE (2013). Iron nutrition and premenopausal women: effects of poor iron status on physical and neuropsychological performance. Annual review of nutrition, 33, 271-88 PMID: 23642204

Pasricha SR, Low M, Thompson J, Farrell A, & De-Regil LM (2014). Iron Supplementation Benefits Physical Performance in Women of Reproductive Age: A Systematic Review and Meta-Analysis. The Journal of nutrition PMID: 24717371

Masters Athletes Need More Protein than Younger Athletes

Masters Athletes may have some nutritional needs that differ from those of younger athletes. By Masters, we’re referring to athletes over age 40. This is currently the cut-off for Crossfit. Here’s what we know about Masters and protein:

  • Masters athletes may need more protein than younger athletes regardless of sport.
  • Consuming more protein may slow normal loss of muscle mass that occurs over time.
  • Masters athletes doing resistance training may need more protein than younger people because they don’t synthesize muscle proteins as quickly.
woman masters crossfit athlete high protein diet
Masters Crossfit Athlete competes in the Crossfit Games Open 14.1 in the 50-54 age category. She is wearing a WODMasters singlet. Check our designs.

Masters Athlete Nutrition: what we know today.

The amount of FDA recommended protein stands at about 0.66 grams per kilogram of body weight.  This number was derived by looking at many studies of people.  Some of the studies looked at the average amount eaten by healthy people.  Others looked at nitrogen balance: how much comes in vs how much comes out.  People who lose more nitrogen than they take in through food are said to be in negative nitrogen balance.  For these studies, the recommended amount would be the amount where the amount of nitrogen coming in is equal to the amount leaving (urine).  There are a number of limits with these approaches.  They do not answer the question of “what is best”.   They have not focused on athletes or older adults.   Weight lifters and others trying to add muscle have traditionally eaten a lot of protein.   Way more than 0.66 grams/kilogram. Eating more than the recommended amount of protein doesn’t seem to hurt.  Just don’t leave out other nutrients.

Cracked Earth Eye Pood Shirt
All Seeing Eye Pood Kettlebell Shirt for men. On request for women.

Scientists who work in this area have concluded that 0.8 g/kg is better for masters athletes than the old level of 0.66 g/kg.  Many people will find number low and may get upset about. Don’t worry if you’ve just had a WTF moment.  After all, we’ve been urged to consume at least a full gram of protein, 1.2 g/kg or even more. This may be perfectly valid if you are interested in strength gain or preservation of muscle mass during aging. We simply don’t know what is “optimal.”  “Optimal” will, of course, depend on many different factors.  The increase from 0.66 g/kg to 0.8 g/kg is 25%.  That is a big jump.

Here’s what may help preserve or increase muscle mass for masters athletes

  • Eat more than 0.8 g/kg/day to increase strength (you have to lift too.)
  • Get some protein soon after a training session
  • Some recommend taking 5 g/day of creatine monohydrate.  There is some evidence that it can boost strength gains and help increase fat free mass.  Keep in mind that creatine can also increase water retention.  Some of the gains in fat free mass may just be water.
  • For endurance: sadly, there is no evidence that carb loading helps.
  • Carbohydrates are important.  If your body doesn’t have carbohydrates it will use some of your protein for energy.  It will use fat too, but it will also use muscle.

What kind of protein is best for Masters Athletes?

There is a lot of research showing that red meat increases risk of cancer.  I know a lot of people like red meat.  But evidence says: avoid it.  If you do eat red meat avoid grilling or charring it.  Burning food creates carcinogens.  Cooking fats at high temperatures produces acrolein.  Acrolein may contribute to development of Alzheimers.  Vegetable protein (beans and nuts) seems to lower risk of cancer.  It also seems to lower risk of heart disease and diabetes.  The paleo diet is against beans.  There is really no reason not to eat beans other than that some popular diet books put them in the “bad” category.  Beans should be well-cooked.  If you are not used to eating beans . . . you will probably get better at digesting them peacefully.  You may even get good at it.

Take away:

It looks like masters athletes need more protein than others.  The  recommended increase from 0.66 g/kg/day to .80 g/kg/day is a 25% increase.  Until we know more, increasing your protein intake may help you maintain or increase muscle mass. Limit red meat. Many people seem to be devoted to red meat, but the vast majority of research indicates it is a risky protein source.  Avoid fish high in mercury (tuna, swordfish).  Mercury accumulates in the body over time and has been linked to a number of poor health outcomes. Increasing protein intake with vegetable protein is a healthy strategy.

 

 

Tarnopolsky MA (2008). Nutritional consideration in the aging athlete. Clinical journal of sport medicine : official journal of the Canadian Academy of Sport Medicine, 18 (6), 531-8 PMID: 19001886

Bazzano LA, He J, Ogden LG, Loria C, Vupputuri S, Myers L, & Whelton PK (2001). Legume consumption and risk of coronary heart disease in US men and women: NHANES I Epidemiologic Follow-up Study. Archives of internal medicine, 161 (21), 2573-8 PMID: 11718588

Position Statement (2010). Selected Issues for the Master Athlete and the Team Physician Medicine & Science in Sports & Exercise, 42 (4), 820-833 DOI: 10.1249/MSS.0b013e3181d19a0b

Can reducing ammonia production during exercise improve performance?

Ammonia may be a central player in fatigue and exhaustion.  Exercise releases of ammonia into the blood stream.  Once in the blood stream it travels to the brain where it can accumulate if the pace of entry is faster than the body’s ability to metabolize it.   Athletes in studies who had the hardest time completing an intense exercise task also had the highest ammonia levels.(Nybo 2005).

The brain gets rid of extra ammonia by combining it with glutamate to produce glutamine.  If the brain is using glutamate to get rid of ammonia it is possible that glutamate levels decrease.    Decreased brain glutamate can impair function and may contribute to some of the wonky feelings of exhaustion.  Glutamate is an important neurotransmitter.  It is an excitatory neurotransmitter.  Glutamate makes it easier for nerves to fire and transmit information.  Without glutamate brain function may slow.  This is a very simplified picture.  However, it may help explain a bit of what is going on with fatigue.  Brain uptake of ammonia has been demonstrated in a number of studies.  One thing that has been noted is that there may be a lot of variation in the amount of ammonia produced.  This was found in a study of highly trained endurance athletes.  Athletes were:

  • young men
  • very similar weight
  • similar height
  • similar VO2max
  • living in Denmark (Nybo 2005).

Is it possible that variability in ammonia levels helps some people go longer or harder than others?  Is it less ammonia production or better brain clearance?  What causes it: genetics, diet, differences in training?

Reducing Ammonia:  Is it possible? Would it help for competition or training? Would it hurt?

There have been several studies that have looked at reducing blood ammonia levels.  Much of this comes from research on people with liver disease.  People with liver disease tend to produce a lot of ammonia.  They may also suffer a lot of muscle loss and brain dysfunction.  Their situation though is quite different from that of an athlete.

Is there any research on reducing ammonia levels during exercise?

Yes. Apparently glucose does.  Subjects (Nybo 2005) who were given glucose supplement had only about a third of the ammonia level as did subjects who did not.  A 2008 paper found that giving professional football players 100 mg per kg of glutamine prior to training reduced ammonia in blood.  Lastly, walnuts.  A study of walnut extracts showed less ammonia in blood of mice after they were subjected to a forced swim test.  Mice receiving walnut extract were able to swim quite a bit longer than those who did not (see reference for details.)  One of the things that was particularly interesting is that mice were subjected to several tests over several weeks.  Performance improved in the Walnut-Extract Mice from week 1 to week 2 to week 3 and then tapered off.  They never dropped to the level of No-Walnut mice.  Here is a link to the graph: Link.  The researchers suggested that Walnuts may reduce ammonia and fatigue through their anti-oxidant properties.

Should I eat walnuts, glucose and glutamine during training?

There is no evidence that walnuts, glucose or gluamine will improve your performance over the long term.  In fact, trying to lessen your ammonia production during training may hurt.  In the Nybo study the athletes with the highest levels of  ammonia in plasma and brain were the athletes who did not get glucose AND had the lowest VO2 max.  VO2 max is a marker of aerobic conditioning.  It is possible that the body gets more efficient in dealing with ammonia produced during exercise.  If that is the case, minimizing ammonia production might also minimize your ability to deal with it.  Its too early to know.

What about walnuts, glucose and/or glutamine for competition?

Hard to say too.  But . . . an ability to reduce ammonia might reduce fatigue and let you go longer or faster.  It might give a competitive edge.  Keep in mind some people may simply be better at metabolizing ammonia.  It might be genetic.  Or it might be from hard training.  For an overview of amino acid metabolism:

 

Masters Crossfit training
One of the world’s top-ranked masters CrossFit athletes trains for the CrossFit games at The Black Box in Fort Worth

Qiu J, Tsien C, Thapalaya S, Narayanan A, Weihl CC, Ching JK, Eghtesad B, Singh K, Fu X, Dubyak G, McDonald C, Almasan A, Hazen SL, Naga Prasad SV, & Dasarathy S (2012). Hyperammonemia-mediated autophagy in skeletal muscle contributes to sarcopenia of cirrhosis. American journal of physiology. Endocrinology and metabolism, 303 (8) PMID: 22895779

Nybo L, Dalsgaard MK, Steensberg A, Møller K, & Secher NH (2005). Cerebral ammonia uptake and accumulation during prolonged exercise in humans. The Journal of physiology, 563 (Pt 1), 285-90 PMID: 15611036

Snow RJ, Carey MF, Stathis CG, Febbraio MA, & Hargreaves M (2000). Effect of carbohydrate ingestion on ammonia metabolism during exercise in humans. Journal of applied physiology (Bethesda, Md. : 1985), 88 (5), 1576-80 PMID: 10797115

Bassini-Cameron, A., Monteiro, A., Gomes, A., Werneck-de-Castro, J., & Cameron, L. (2008). Glutamine protects against increases in blood ammonia in football players in an exercise intensity-dependent way British Journal of Sports Medicine, 42 (4), 260-266 DOI: 10.1136/bjsm.2007.040378

Paleo Breath and Paleo Sweat

If you have recently started a high protein diet and are wondering why your breath smells so bad . . .

Paleo Breath is common among people following the paleo diet (aka caveman diet). There may be two factors involved in Paleo Breath. The first is the accumulation of ketones from fat metabolism.  Ketones are excreted in urine, but there are ketones that also volatile . . . those come out in breath too. Acetone is one of these.   Acetone in breath smells a bit like rotten apples.  The other bad breath agent showing up in paleo diet or low carb diet is ammonia.  Ammonia may show up in breath when people metabolize protein for energy.  Ammonia smells more like urine.  Urine breath may be more disagreeable than rotten apple breath. Or not.  You can get ammonia breath without being on the paleo diet too.    Ammonia breath happens when people are burning protein.

Hard workouts makes your clothes smell worse.

If you have noticed a sudden worsening of smell in your locker or gym bag it may be a sign you are really pushing it during your workouts.  Congratulations. Ammonia concentrations in sweat increase during intense exercise as well as when protein is metabolized for energy.  Ammonia in sweat will make your workout clothes smell nasty.   It may make you smell bad too.

Cracked Earth Eye Pood Shirt
Look good even if you smell bad with a WODMASTERS limited edition weightlifting shirt. Dutch Lowy, model.

Ammonia in breath: a hot research topic

A lot of exciting work is being done on ammonia in breath.  While ammonia breath in people who follow high protein, low-carb or paleo diets may be an annoyance or embarrassment, ammonia in the breath can be caused by other problems and signal health concerns.   Ammonia in breath is elevated in people with kidney and liver disease.  Ammonia in breath may also be a sign of esophogeal or gastric problems (like cancer) or lung infections.  If you are eating a protein diet/paleo diet and are otherwise healthy the chance that your bad breath is being caused by a serious health problem are extremely, extremely small.  Still, research on breath is just fascinating.   We may soon be able to diagnose medical problems by having someone breath into a device that would create a profile of breath components.  This may help catch cancers early, so they could be treated earlier and more effectively.  It may also help us better understand physiology in general.  A just-published study has found that ammonia levels are elevated in the breath of obese children.  The obese children in the study also had other factors in breath that differed from their normal-weight peers.   Its not clear yet what elevated ammonia levels mean in over weight children.  A sign of impending diabetes perhaps?

Breath Profiles for Health and Sports

While research on breath is focusing on detection of serious health problems there are so potential applications for general health and sports performance. Ammonia levels in breath (or perspiration) may help coaches and athletes determine exactly when an athlete researches a particular training threshold.

Take Away

Yes, your clothes will smell like cat pee if you don’t wash them after a heavy workout.  If you are following a high protein/paleo diet, showering will help control body odor by washing high-ammonia perspiration off your skin.  Mouth bacteria break-down products form ammonia in breath too. They can produce enough ammonia to confound breath analysis studies.  Nose sampling gives better data. Keeping you teeth and mouth clean should help with paleo breath too.

 

Effros RM, Casaburi R, Porszasz J, Morales EM, & Rehan V (2012). Exhaled breath condensates: analyzing the expiratory plume. American journal of respiratory and critical care medicine, 185 (8), 803-4 PMID: 22505753

Alvear-Ordenes I, García-López D, De Paz JA, & González-Gallego J (2005). Sweat lactate, ammonia, and urea in rugby players. International journal of sports medicine, 26 (8), 632-7 PMID: 16158367

Alkhouri N, Eng K, Cikach F, Patel N, Yan C, Brindle A, Rome E, Hanouneh I, Grove D, Lopez R, Hazen SL, & Dweik RA (2014). Breathprints of childhood obesity: changes in volatile organic compounds in obese children compared with lean controls. Pediatric obesity PMID: 24677760

A New Source of Protein for the Athletic and the Sedentary?

A New Source of Protein?

This is an odd and interesting bit of research.  It relates to reaborption of nitrogen . . . and presents the possibility that more protein is conserved than previously thought.  First dietary nitrogen 101: Nitrogen is a major component of amino acids.  Amino acids are needed to form proteins.  We can synthesize some amino acids ourselves, but others need to be obtained through diet.  Dietary protein provides nitrogen and amino acids from plant or animal sources which are resynthesized into human proteins.  Unused nitrogen is converted into Ammonia and Urea and excreted.

Can nitrogen be reabsorbed from the intestines?

WODMasters Eye Pood Kettle Bell
Even if you don’t have the right microbial stuff, you can still look awesome and powerful with the right shirt

The answer is a shocking “maybe.”  A new nutritional study (published ahead of print in the Journal of Nutrition) has found that nitrogen appears to be reabsorbed.  This makes little sense at first glance.  Until we consider the vast populations of microorganisms that reside in the gut.  Until recently, they were all thought of as “germs” that needed to be quashed.   That has changed.  We are learning more and more about how important they are for our health and even our survival.

The study is titled:

Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet.

Valine is an essential Amino Acid, so these animals were fed a protein-deficient diet.   Then researchers administered urea or casein into the cecum of pigs.  Let’s consider this research a step toward greater understanding of how nitrogen may be recycled in living animals.  Not a new way to increase protein for strength.  (Although who knows.  It might work.) The urea was synthesized using Nitrogen-15.  Dietary nitrogen is Nitrogen 14.  Using nitrogen-15 lets the team know where the cecum-delivered nitrogen ended up.

Findings:

Researchers found that more than 80% of the cecum delivered nitrogen was absorbed.  Some of it was excreted in urine, but some was retained. This is a shocker.  I know.   Humans cannot synthesize protein using nitrogen.  So WTF?  The researchers propose that urea traveled through the bloodstream and into to the small intestine.   Bacteria (some of which can make amino acids using urea or plain nitrogen) in the small intestine then used the extra urea to make amino acids.  Amino acids produced by bacteria could then be absorbed the host (animals).

Takeaway:

More research would need to be done to confirm that this happens.  But it is very interesting.  Humans vary in the types of bacteria they host.  Bacterial populations vary according to diet, environment, chance (?) and who knows what else.  Do people get extra protein from bacteria?  Does this happen under normal circumstances (i.e. not piped in through the back end.)?  One thing is sure: there is a lot to learn. ResearchBlogging.org

Columbus DA, Lapierre H, Htoo JK, & de Lange CF (2014). Nonprotein Nitrogen Is Absorbed from the Large Intestine and Increases Nitrogen Balance in Growing Pigs Fed a Valine-Limiting Diet. The Journal of nutrition PMID: 24647394

Low Vitamin D, Atherosclerosis and CardioVascular Disease

Crossfit or Kettlebells: New mens shirt
Watch for our new 2014 Eye Pood Shirt. In press as we speak.

Vitamin D has received tremendous interest over the last ten years.  One of the many things to come out about Vitamin D is that is that it protects against vascular calcification.  Vascular calcification causes or contributes to:

  • Stiff arteries
  • Poor elasticity
  • Increased blood pressure
  • Kidney damage
  • Increased risk of heart attack and stroke
  • Congestive heart failure
  • Early death

That is terrible.  Not long ago calcification was considered a normal part of aging. Then it was considered an issue of cholesterol and a high fat diet.  The contributions of dietary cholesterol and dietary fats continue to be explored and challenged, however, researchers are uncovering other factors.  Vitamin D insufficiency has been strongly associated with risk of poor health and death.  This includes increased risk of death from cardiovascular disease.  Research groups are  now working to figure out more of the details.

Chronic Vitamin D Deficiency vs. On-again Off-again Vitamin D deficiency

A recent article in the Journal of Nutrition reports on an investigation of Vitamin D and vascular calcification.  The study used groups mice.  It lasted 32weeks.  Different groups of mice were fed either

  1. mouse version of a typical Western diet with adequate vitamin D for 16 weeks
  2. mouse version of a typical Western diet with low vitamin D for 16 weeks
  3. mouse version of a typical Western diet low vitamin D for 32 weeks
  4. mouse version of a typical Western diet with low vitamin D for 16 weeks then switched to a normal D diet for another 16 weeks.

Research Findings

Mice on the 16 week low vitamin D diet had more calcified arteries than mice fed the higher vitamin D diet, but not by that much.  (See the article for details).  The low vitamin D diet, however. turned up something interesting:

  • Vascular cells in the Low Vitamin D mice appeared to change into osteoblast-like cells.  Osteoblasts are build bone.  They also create dense, crosslinked collagen and create a matrix for bone.   This may not be the best thing for vascular health.
  • Mice fed a low D diet for 32 weeks had significantly more plaque than other mice, more osteoblast-like cells and more tumor necrosis factor.
  • Mice who were returned to the normal D diet had less calcification.  This is a nice finding.  It looks like increasing vitamin D  will improve the quality of arteries if your diet has been low in vitamin D.

Takeaway:

It looks like low vitamin D plays a strong role in hardening of the arteries. Not all is lost,  Damage you have accumulated to date may be reduceable.  Please note too that this was a study of dietary vitamin D and not vitamin D made through sun exposure.  You can make your own vitamin D with exposure to sun light.  Please remember not to go overboard.  Too much vitamin D may also cause calcification of arteries.

Nadine Schmidt, Corinna Brandsch, Alexandra Schutkowski, Frank Hirche, & Gabriele I. Stangl (2014). Dietary Vitamin D Inadequacy Accelerates Calcification and Osteoblast-Like Cell Formation in the Vascular System of LDL Receptor Knockout and Wild-Type Mice Journal of Nutrition

Ellam T, Hameed A, Ul Haque R, Muthana M, Wilkie M, Francis SE, & Chico TJ (2014). Vitamin d deficiency and exogenous vitamin d excess similarly increase diffuse atherosclerotic calcification in apolipoprotein e knockout mice. PloS one, 9 (2) PMID: 24586387

Dietary Fat Preserves Muscle?

Preservation of lean muscle mass matters for long term health and function.  It is also important to those who want to gain muscle mass so they can look hot and/or awesome.   it is also important for strength and for athletic performance. Whatever your interests, here is a report of a recent study on dietary fats and muscle mass.

Sprinting and Jumping help you stay strong so you can beat up young people.
Dietary fat may help you stay strong so you can beat up young people.

Dietary Fat and Protein Turnover

Dietary fat may regulate protein turnover.  The thought is that dietary fats influence both inflammation and insulin.  This study was published in this month’s issue of the Journal of Nutrition.   Study subjects were 2,689 women who are part of a study of twins in the UK.  Data was collected on:

  • Percent of Calories obtained from Fat
  • Fatty acid profile
  • Fat -free mass in kilograms (an indicator of muscle mass)
  • Fat-free mass measured by X-Ray absorptiometry

Results of the Dietary Fat and Muscle Study

  • Women whose diets were higher in polyunsaturated fatty acids had higher fat-free mass (more muscle).
  • Women who got more of their calories from fat had less fat free mass (less muscle)
  • Women who ate more saturated fat had less fat free mass (less muscle)
  • Women who ate more unsaturated fatty acids had less fat free mass (less muscle)
  • Women who are more transfats had less fat free mass (less muscle)

Women who were in the top 20% for energy intake from polyunsaturated fatty acids had about a pound more muscle mass than women who were at the bottom 20% for polyunsaturated fatty acid.  This is about the same difference in muscle mass that would be seen in a 10 year aging period.  You could look at this and say that a diet high in polyunsaturated fatty acids saves 10 years of muscle aging.  And you might be right.  Polyunsaturated fatty acids reduce inflammation and seem to protect against cardiovascular disease and cancer as well.  We don’t know what drives age-related muscle loss.  It might be related to the same factors that drive cell-aging in general.  

The Simple Takeaway for Dietary Fat and Muscle Mass

ResearchBlogging.orgThis is the first study of its kind and more research is needed to figure out what is going on.  However, this study supports the idea that a diet higher in polyunsaturated fatty acids is protective against loss of muscle mass.  As many are sure to proclaim: correlation is not causation.  That claim does not end arguments, although it is often used that way.  It simply means that we need to know more.   This is an interesting study that should lead to further investigation.  Thanks to the team (Alisa Welch, Alex MacGregor, Anne-Marie Minihane, Jane Skinner, Anna Valdes, Tim Spector and Aedin Cassidy) for your hard work.

 

Welch AA, Macgregor AJ, Minihane AM, Skinner J, Valdes AA, Spector TD, & Cassidy A (2014). Dietary fat and Fatty Acid profile are associated with indices of skeletal muscle mass in women aged 18-79 years. The Journal of nutrition, 144 (3), 327-34 PMID: 24401817

New Evidence on the Benefits of Sprinting for Long-Term Health and Fitness

ResearchBlogging.orgBenefits Sprinting and Jumping: New Evidence

I began distance running at the age of 12 and have kept with it for decades now. Running at a mellow pace has helped me unwind, de-stress and keep my sanity through turbulent times. Until I started CrossFit about five years ago. While I miss the runners high there are some great benefits to including weights, varied movement and group training. There is plenty of research on the benefits of running and aerobic exercise. Research on the benefits of resistance training and high intensity interval training (which resembles CrossFit in some respects) is showing that these forms of exercise are important. They may, in fact, be more effective and provide greater benefits for long-term health.  Here is an outline of some possible benefits or sprinting.  Or being a sprinter.

Sprinting and Jumping help you stay strong so you can beat up young people.
Sprinting and Jumping help you stay strong so you can beat up young people.

Today’s Study: Benefits of Sprinting (or being a Sprinter) vs. Other Types of Runners

Today’s study was published last year (2013) in the journal Osteoporosis International.  Subjects were Experienced Masters Runners between 35 and 90 years of age.   Runners were asked to identify their strongest running distance:

  1. Short Distance (400 meters, triple jump and/or long jump
  2. Middle Distance (800 meters to to 1500 meters
  3. Long Distance (2000 meters to marathon)

Information on numbers of years of training, age, gender, age of menarche, and age of menopause (when appropriate) were collected.  Subjects then completed a series of tests:

  1. Bone Mineral Density
  2. Lean Body Mass Evaluation
  3. Grip Strength (this is a marker of general strength and a predictor of strength in old age).
  4. Neuromuscular Function (evaluated by counter movement jumps and hopping)

Findings (aka Results)

Short distance runners and jumpers did better on all measures with the exception of arm bone mineral density.  There were no significant differences in arm bone density among the athletes tested.  While there are a number of limits to the study the sprinters have better grip strength, higher lean muscle mass, stronger bones, and better neurouscular function than middle or long-distance runners.  An unfortunate finding was that all types of athletes experienced a similar rate of decline in strength and coordination with age. Still, it seems better to start high and land in the middle than to start in the middle and face plant during one’s senior years.

Study Limits:  More research is needed on the long-term benefits of sprinting

The study has a number of limits.  Here they are a few that were apparent to me.  There may be more.  Take a look at the article.  There is a link below.

  1. It was not clear if people who identified as sprinters, middle distance runners or long distance runners trained for these events or if they preferred them.
  2. Subjects may have simply had the body and neurological types to be sprinters, jumpers, middle distance or long distance runners and would have showed similar results whether they had been Masters Runners or not.  Are there benefits or sprinting?  Or benefits from being someone with a sprinters body type?  It would also be good to know what differences are seen between runners and jumpers.

Takeaway:

This study supports growing evidence that sprinting may provide benefits not found in jogging or long distance running. Check out this 61 year old Masters Athlete racing against a 16 year old soccer star.
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Gast U, Belavý DL, Armbrecht G, Kusy K, Lexy H, Rawer R, Rittweger J, Winwood K, Zieliński J, & Felsenberg D (2013). Bone density and neuromuscular function in older competitive athletes depend on running distance. Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA, 24 (7), 2033-42 PMID: 23242430

High protein diet is protective for older people, but may be unhealthy for others

We’ve written several articles on the apparent benefits of a higher protein diet for the older athlete.  Loss of muscle mass starts fairly early and loss of strength is often apparent by middle age.  We do not know how much protein intake is ideal for humans.  High protein diets for older people have been geared towards controlling sarcopenia.  Sarcopenia is the term used to describe the muscle loss that happens as people age.  Sarcopenia is a major cause of frailty.  Osteoporosis, where loss of calcium from bones leads to brittleness and fractures, is the other big problem.   Sarcopenia and osteoporosis can be worse for women who have less bone mass and less muscle mass to start with.  A number of studies have shown that older people preserve more muscle if their protein intake is increased.  If older people can preserve more muscle that should mean fewer people needing assisted-living.  Exercise, including resistance exercise also helps preserve muscle.  Exercise also strengthens bone and protects against osteoporosis.  As for the older athlete, preservation of muscle mass may provide a competitive edge.  For more easy-going people, preservation of muscle mass may mean:

  • less of the sinking feeling you get when you realize you know exactly where your body should have been when you took that flying leap for a frisbee.
  • fewer pained expressions on the faces of children when you fail a back flip
  • less aggravation opening jars
woman masters crossfit athlete high protein diet
Masters Crossfit Athlete competes in the Crossfit Games Open 14.1 in the 50-54 age category.

A new study by a team of researchers from the US and Italy examined protein intake in adults over age 50 compared with rates of Cancer, Diabetes, Mortality in general and IGF-1 (a growth hormone) levels.  Study subjects were divided into two groups: ages 50 to 65 and those over 65.  For people ages 50 to 65 a high protein diet increased risk of cancer, diabetes and death in general.  IGF-1 levels were also higher in these adults.  IGF-1is a growth hormone that may preserve muscle mass, but may also increase risk of cancer.  Middle-age users of deer antler velvet, which contains IGF-1, beware.  Researchers also found that people who ate more plant protein had lower death rates than people who ate more animal protein.  In bullet points:

High protein diet for people age 50 to 65

  • High animal protein diet increased risk of cancer by 400% in adults 50-65
  • High animal protein diet Increased risk of death by 75%
  • High animal protein diet increased risk of death from diabetes-related causes by 500%
  • High plant-based protein diet showed little to no increase in death or cancer risk

High protein diet for people over age 65

  • high protein diet reduced risk of cancer and death in people over age 65
  • Risk of death from diabetes-related causes was the same as it was for adults 50-65

Conclusions for dietary protein intake:

The researchers in this case also compared epidemiological findings with data derived from mice, which is unusual.  One of their conclusions was that a low protein intake diet during middle age followed by a high protein intake in later age may “optimize healthspan and longevity.”  I would add some considerations to that:

  1. It didn’t seem to be protein in itself thatwas the main culprit in the study, although there was some interesting data on ifg-1 levels and protein intake.  One of the problems with some forms of animal protein (meat) is that carcinogents (cancer causers) may form during high heat cooking. 
  2. Animal fat will contain more lipophilic chemicals than vegetable fats.  Some lipophilic chemicals build up in humans over time. 
  3. It seems likely that something besides protein is causing the problem. 
  4. There may be other considerations for post-menopausal women, who seem to weather aging (functionally) better when protein intake is higher.
  5. People age 50-65 are different than people 65 and older.  The 65 and older group may already have weeded out people who were vulnerable to heart disease.  (This would probably not hold for cancer).

High protein diets have been popular for a number of years now.  High protein diets, especially meat based high protein diets, have been especially popular in the Crossfit Community.  Unless you are a middle aged adult, a high animal protein diet may be bad for your long-term health.    It would be nice to know what the results would be if high-fat/high protein/poor lifestyle/obesity was separated from high protein/healthy lifestyle/healthy weight.  Hopefully the researchers will continue this line of inquiry. 

 

Levine, M., Suarez, J., Brandhorst, S., Balasubramanian, P., Cheng, C., Madia, F., Fontana, L., Mirisola, M., Guevara-Aguirre, J., Wan, J., Passarino, G., Kennedy, B., Wei, M., Cohen, P., Crimmins, E., & Longo, V. (2014). Low Protein Intake Is Associated with a Major Reduction in IGF-1, Cancer, and Overall Mortality in the 65 and Younger but Not Older Population Cell Metabolism, 19 (3), 407-417 DOI: 10.1016/j.cmet.2014.02.006

Gregorio L, Brindisi J, Kleppinger A, Sullivan R, Mangano KM, Bihuniak JD, Kenny AM, Kerstetter JE, & Insogna KL (2014). Adequate Dietary Protein is Associated with Better Physical Performance among Post-Menopausal Women 60-90 Years. The journal of nutrition, health & aging, 18 (2), 155-60 PMID: 24522467

Beasley JM, Wertheim BC, LaCroix AZ, Prentice RL, Neuhouser ML, Tinker LF, Kritchevsky S, Shikany JM, Eaton C, Chen Z, & Thomson CA (2013). Biomarker-calibrated protein intake and physical function in the Women’s Health Initiative. Journal of the American Geriatrics Society, 61 (11), 1863-71 PMID: 24219187