Masters athletes protein intake improves recovery. Virgin initiation ceremony for the Hash House Harriers, Grenada West Indies

Can stress from noise make you gain weight?

Can stress make you gain weight? Mona Lisa Kettlebell shirt in vintage heather gray.

Mona Lisa Kettlebell shirt in vintage heather gray. Looking awesome in one of our shirts can help reduce stress. Check out our WODWomen Etsy shop. Click the pic.

Can stress make you gain weight?  Not too long ago that would have been considered a funny question. Weight gain, you would have known for fact, is caused by eating too much and exercising too little.  These things are certainly important, but research indicates that is not the entire story.  There are other factors. Research indicates stress, including stress from such simple things as noise, can play a role in weight gain.

Can stress make you gain weight?

Surely there are many factors involved in the current obesity epidemic.  I’m sure you’ve heard plenty of people blame the loss of recess and gym class in schools, the supersized drinks, and the easy availability of junk food,  There is also the lack of time needed to plan, shop for, and prepare the healthy, home-cooked meals that some of us stealthily passed to the dog under the table during our childhoods.  Unwanted vegetables, I recall, were stashed in pockets.  But why are so many people struggling today with body weight?  If you stop to think about it, our bodies do an amazing job of maintaining body weight.  Our weight doesn’t, unless something is really wrong, seesaw all over the place.  When we do gain weight, it tends to move gradually upwards, and then is hard to take off.  This is due to complex interactions of hormones, which we do not completely understand.  Note here: what we don’t know about the regulation of our own bodies could fill a barn. Somewhere out there is the answer to the question how can stress make you gain weight.

How stress can make you gain weight

When a person experiences long-term stress the body adapts by increasing levels of cortisol.  Cortisol does a number of things.  Cortisol elevates blood sugar, suppresses your immune system, and breaks down muscle to use it for fuel.  Fat, tends to build up, especially around the waist.  This is a very simplified nut-shell explanation.   For an excellent and enjoyable discussion check out this video featuring stress researcher Robert Sapolsky.

Contemporary life is full of stressors.  This can include things we think we have completely tuned out, like noise. Living in an area with heavy traffic noise has been associated with cardiovascular disease.  It has also been associated with metabolic disorders and sleep problems.   Noise as a factor in body fat was studied by a group of Danish researchers.  They had a cohort of over 57,000 people.  This is a lot of people, which makes the study a lot more powerful than studies that look at small numbers of people.   The results of the study found that people in areas with noise levels of 60+ decibels had larger waists and higher BMI than people living in quiet areas (20 or fewer decibels of noise).   Researchers controlled for socioeconomic factors, history of smoking, level of physical activity and exposure to air pollution which are also associated with body weight and metabolic disorders.

Can stress make you gain weight?  Maybe.  Can noise make you gain weight?

Etsy kettlebell shirt at the WODWomen Etsy shop

Relieve stress with a quiet statement. You can get this design on an awesome shirt at our WODWomen Etsy shop. Click the pic.

This study indicates that people living with noise have bigger waists and are heavier, as a whole, than people whose homes were quiet.     What makes for a noisy home?  The researchers were particularly interested in noise from traffic and railroads.  The cutoff for “noisy” was 60 decibels.  This is not considered all that loud.  Background conversation in a restaurant will clock in at about 60 decibels.   Being a hundred feet from an air conditioner can too.  Driving in a car, presumably with the windows shut will be around 70 decibels and conversation at home is normally around 50.  To get into the quiet category (20 decibels or less) your average background noise would consist of gently rustling leaves and whispering.

Things to consider for the can stress make you gain weight question

Reducing stress in your life, including extra noise, may help you improve your health and make losing weight easier.  However, not everyone responds to stress, including the stress of noise, in the same way.  Some people find quiet very stressful.  Some noise can be soothing.  Tweeting birds and babbling brooks make noise too.

ResearchBlogging.org

Christensen JS, Raaschou-Nielsen O, Tjønneland A, Overvad K, Nordsborg RB, Ketzel M, Sørensen TI, & Sørensen M (2015). Road Traffic and Railway Noise Exposures and Adiposity in Adults: A Cross-Sectional Analysis of the Danish Diet, Cancer, and Health Cohort. Environmental health perspectives PMID: 26241990

World War Fit Masters Competition at Rockwall Texas

Age and Exercise-induced Muscle Damage can increase risk of heat stress.

Muscle damage and heat and age.

Many people dislike working out in the heat.  There are also serious safety concerns to consider.  Heat stress, or course, can kill . . . it can also make people sick.  Those who recover from heat stroke, the more severe form of heat illness, can suffer life-long difficulties with regulation of body temperature.  Older people, and presumably older athletes, are more vulnerable to heat stress.  There may be many reasons for this.  Older people may sweat less and they may sweat less efficiently (Inoie 1996).  Vasodilation, an important cooling mechanism that shunts blood flow to the surface where it can cool, is less efficient in older adults as well (Smith et al. 2013). Thirdly, older athletes may be slower to recover from exercise-induced muscle damage.  Exercise-induced muscle damage can increase production of pyrogens, specifically interleukin-6, tumor necrosis actor and interleukin-1-beta (Fortes et al. 2013). This research is important (and new at least as of 2013). The next section of this article addresses risk factors for heat illness.  Please skip ahead if you know all this stuff already.

Risk Factors for Heat IIlness other than Muscle Damage

There are many known risk factors for heat illnesses.  Among them are:

  • Being in poor physical condition
  • Being overweight
  • Various medical conditions
  • Already being under stress from lack of sleep
  • Being over-dressed
  • Working out in hot, humid conditions
  • Not being heat acclimated

Some people will still get heat stroke or heat illness even though they have not been suffering from any of the above conditions.  The research discussed here is an attempt to determine if exercise-induced muscle damage increases risk of heat injuries.  The hypothesis is that muscle damage increases inflammation, which upregulates productions of pyrogens, which adds additional heat stress.   Additional heat stress, induced by the pyrogens, may be enough to tip an individual into heat illness or heat stroke.  Pyrogens, for those who don’t know, are chemical agents that trigger fevers.

There is good evidence that exercise can cause fever.  And that fevers can be blocked by anti-bodies that oppose inflammatory agents.  A previous study collected plasma following an exercise protocol and injected it into rats.  The rats then developed fevers. A second group of rats were injected with human plasma collected from donors prior to exercise, and no rat fevers developed.

Protocol for heat and muscle damage study:

Subjects for the muscle damage study were 13 young men (not heat acclimated).  The muscle damage was induced by having subjects run downhill (at a -10% gradient) for 60 minutes (For those who commented that a -10% grade run for 60 minutes couldn’t possibly cause muscle damage . . . it will if you are not adapted to running downhill.)   The second protocol required that subjects run at a +1% gradient, that was not muscle damaging.  Subjects performed the tests twice, 14 days apart, in a counterbalanced manner.  Researchers assessed evidence of heat strain 30 minutes after the protocol and again 24 hours after completion of the protocol.  The time point of 24 hours post-protocol was chosen to coincide with peak (or close to peak) inflammatory response.  Please see the figure for clarification.   For full details please read the original paper (reference below).

Heat Stress Experimental Protocol

Experimental protocol

 

Results

Rectal temperatures were higher 30 minutes after the downhill runs, even though both protocols were of the same exercise intensity.  In addition, Interleukin-6 was elevated following the downhill run and subjects reported feeling “hotter”.  Rectal temperatures had decreased 24 hrs later, but remained slightly higher than normal (0.17 degrees C).  That 0.17 degrees is probably not physiologically significant, but interesting that it was still elevated an entire day after the workout.  Researchers also acknowledged that eccentric exercise impairs glucose synthesis, therefore it remains possible that diminished glucose may have contributed to the results found in the study.

What does this mean for us?

One important finding was that pyrogens (interleukin-6) were highest 30 minutes after the protocol.  They remained elevated above normal 24 hours later, but had declined considerably.  Given this information, one can imagine that individuals completing multiple workouts in quick sucession (as happens during crossfit competitions) may experience staggered accumulations of pyrogens.  This would leave athletes at greatest risk of heat illness or heat stroke at the end of the workout cycle (or sequence of WODs).  If you are a Crossfit trainer, competitor or interested spectator you may wish to take any potential increased vulnerability to heat stroke or heat illness into consideration. People at risk of rhabdomyolysis are likely at increased risk of heat illness as well.  Fever, after all, is one of several signs of rhabdo. The question may be raised (and its an interesting one): Will taking anti-inflammatories protect someone from heat stroke or heat illness? I would need to read more on that, but off the top, possibly not.  Ibuprofen, for example, increases production of Interleukin-6, which would make the situation worse.  Aspirin?  Maybe, but it may end up causing other problems.

Keeping cool.

A few people have asked for more information on how to keep cool.  Most of these are pretty well-known:

  • Avoid dark colors if you are working out outdoors
  • Drink plenty of water
  • Keep air circulating if you are indoors or use air-conditioning
  • Dress in thin, light, minimal clothing (while avoiding sunburns).

There has been fairly recent research on the effects of hand cooling on internal temperature.  You can read about it here.  I’ve tried running in the heat while holding frozen water bottles.  I think it works.  Lastly, while we all “know” about how to keep cool, a lot of people skip steps.

For those wanting a simpler synopsis of the article and a little more information on heat stroke and heat illness .  .  .

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Exercise induced Muscle Damage, Heat and Rhabdomyolosis

CrossFit Workout and Heat Stress

CrossFit Workout At CrossFit Seven in Fort Worth, TX

 

Exercise-induced Muscle Damage, Rhabdo and Heat

Most people in CrossFit are probably well aware of risks of rhabdomyolosis.  Rhabdomyolosis occurs when muscles are damaged severely.  Broken down proteins enter the blood stream and can clog up the kidneys.  You can get muscle damage without rhabdomyolosis.  It happens all the time.  Most of the time it is minor and part of training.  However, small amounts of muscle damage may increase a person’s risk of heat illness.

Heat Illnesses include:

  • Heatstroke – is life-threatening.   Temperature can shoot up to the point of brain damage and death.  A person with heat stroke may have dry skin, strong pulse and feel dizzy.
  • Heat exhaustion – not as bad as heat stroke, but can come before heatstroke.  People with heat exhaustion may sweat heavily, have rapid breathing, and a fast pulse.
  • Heat cramps
  • Heat rash

New research shows “exercise-induced muscle damage” increases risk of heat illness.   This is different from exercise-induced heat illness, which may not involve any muscle damage.  The study looked at runners exercising under hot, humid conditions.  Thirty minutes of exercise in hot, humid conditions increased levels of pyrogens in blood over controls.  Pyrogens are substances that cause fever.  Working out in the heat with a fever seems like a particularly bad idea.  The pyrogens subjects’ blood included interleukin 6 which is associated with inflammation. Pyrogens remained higher 24 hours later. This might mean that the risk of heat stress may build a little more every day.  If you do a crossfit workout, or train at anything every day your risk of heat illness may increase a little more every day. People adapt to exercise and heat exposure.  We become better at handling heat over time. The study was done with athletes who were not heat acclimated.  Still, there is reason to be careful.  Subjects exercising in the heat also experienced more muscle soreness the next day.

Conclusion for CrossFit Trainers and CrossFit Athletes

Muscle damage may increase risk of heat stress.  Masters athletes may be at greater risk of heat illness.  If you are a Masters Athlete and notice that you are having a harder time coping with the heat, it is not “all in your head.”  Heat adaptation also happens.  It may take longer than it did when you were in your 20s.  Be patient.  Understanding physiology may help.  It helps for me. Notes:  The featured photo is from CrossFit Heath’s recent fund-raising Masters Crossfit Competition organized by World War Fit.   Bradford CD, Cotter JD, Thorburn MS, Walker RJ, & Gerrard DF (2007). Exercise can be pyrogenic in humans. American journal of physiology. Regulatory, integrative and comparative physiology, 292 (1) PMID: 17197641 Fortes MB, Di Felice U, Dolci A, Junglee NA, Crockford MJ, West L, Hillier-Smith R, Macdonald JH, & Walsh NP (2013). Muscle Damaging Exercise Increases Heat Strain during Subsequent Exercise Heat Stress. Medicine and science in sports and exercise PMID: 23559121 Inoue Y (1996). Longitudinal effects of age on heat-activated sweat gland density and output in healthy active older men. European journal of applied physiology and occupational physiology, 74 (1-2), 72-7 PMID: 8891503 Smith CJ, Alexander LM, & Kenney WL (2013). Nonuniform, age-related decrements in regional sweating and skin blood flow. American journal of physiology. Regulatory, integrative and comparative physiology, 305 (8) PMID: 23926135