Tag: Over 50

Yes You Can Reverse The Effects On Your Heart Of Being Sedentary And Middle-Aged

When I was a younger trainer the only things that mattered for me as an individual in the gym as well as in my program design for clients was developing strength, adding muscle and burning off body fat.  Two and a half decades later those are still the primary things that clients are interested in focusing on and what I spend most of my time helping people address, however as I embrace middle age other important aspects of health and fitness are becoming more of a concern.  For myself and for my clients.

I was always a strength oriented athlete, and I use the words strength and athlete loosely.  I was neither particularly skilled athletically or strong until I found the gym.  In the weight room I found an environment where I was able to excel and use my particular build to great advantage.  If something involved moving heavy weights I was all over it.  Aerobically oriented sports were never my forte.  I recognized the importance of cardiovascular fitness and programmed those components for my clients but it was never the focus.  Without question the only ones who did their cardio were those who were excessively focused on body composition and burning calories.

These days I find myself thinking about the risks of heart disease, the decreases in athletic performance and the capacity to perform everyday physical activities that clients are encountering.  How to maximize risk reduction for diabetes, cancer, stroke and a myriad of other life limiting conditions.  More than ever I wish my clients would make time to exercise, specifically aerobic exercise that trains their cardiovascular systems.  Recently I came across an outstanding study that not only reinforced my concerns about this topic but also demonstrated the impact that regular, consistent aerobic exercise has on significantly reducing the impact of aging and a sedentary lifestyle.  One of the most important pieces of the study is the amount of exercise that is necessary to achieve what literally are time reversing impacts on our hearts.

Put Some Heart In It

Our left ventricle is responsible for pumping oxygenated blood to the rest of the body.  In a healthy heart, as blood fills the left ventricle it increases the stretch on the muscle tissue that forms the ventricle. This stretch on the muscle tissue results in a stronger contraction.  If an increased amount of blood is pumped into the left ventricle the stretch on the muscle tissue is even greater and the resulting contraction is greater.  This means even more blood is pumped from the heart to the rest of the body.  We refer to the amount of blood that is pumped from the heart with each beat as the stroke volume.  Being able to increase the stroke volume, pump more blood, during activity is generally a good thing.

If less blood fills the left ventricle there is less stretch on the muscle tissue and the result is a weaker contraction.  This means less blood is then pumped from the heart, a lower stroke volume.  So anything that causes less blood to fill the left ventricle between each beat or reduces the force with which the ventricle contracts is detrimental.

Now for the bad news, as we age the left ventricle tends to get stiffer.  This results in a decrease in the amount of blood that can fit in the chamber.  This is a problem because it means there is less blood available to be pumped out.  The reduced amount of blood also places less stretch on the muscle tissue resulting in a weaker contraction.  As we just learned these two things result in a lower stroke volume.

Not only do we see a reduction in stretch on the muscle tissue because of the reduced amount of blood in the ventricle, we also see a reduction in stretch on the muscle tissue because the muscles themselves have become stiffer and thicker.  Unlike skeletal muscles where thicker means stronger, with cardiac muscle tissue thicker does not necessarily always mean better.  So essentially there are now three factors resulting in a lower stroke volume; less blood filling the chamber and available to pump out, less stretch on the muscle tissues because of the reduced amount of blood resulting in a weaker contraction and less stretch on the heart muscle because it has become stiffer and thicker.  In a nutshell, aging sucks for our hearts, far more so if you are sedentary.

By the time someone reaches their senior years (65+) if they have been sedentary, adding in moderate aerobic exercise is not very effective in reversing the stiffness that is found in the left ventricle (Don’t stop exercising seniors.  Exercise is still effective through other mechanisms).  By contrast, masters athletes that have engaged in a lifetime of physical activity tend to show hearts that appear and function as they would in much younger individuals (Arbab-Zadeh et al 2004).  While it might not be reasonable to expect everyone to exercise at the same volume and intensity of competitive athletes, 4-5 days a week of regular exercise over a lifetime does appear to provide most of the benefits (Bhella et al. 2014).

Researchers have determined that this stiffening process begins in and can be identified in middle age (Fujimoto et al. 2012).  This led researches to question if they could provide an intervention in sedentary middle age individuals that would stop, limit or reverse the negative changes seen in the heart.

The Study Details

Howden et al. (2018) theorized that if they took a group of sedentary middle-aged individuals and put them on an exercise program performed 4-5 days a week consisting of cardiovascular exercise performed for at least 30 minutes, including 1-2 high intensity interval training sessions, they could prevent left ventricular stiffening.

There are four main reasons we should consider this a higher quality piece of research.  First, it was a prospective study.  Subjects were put on an intervention and then the results were measured instead of the majority of similar research that is retrospective in nature, meaning they take a current population and look back at what they report they did in the past and try to determine to what extent their prior behavior contributed to their current status.  Secondly the study also included a parallel control group whose activity was supervised and their results directly compared to the intervention group. Third, the study was randomized.  Once subjects were determined to be eligible for the study they were randomly assigned to either the intervention group or the control group.  Fourth, the study lasted for two years.  Prospective studies are very complicated to conduct and most similar types of research in this area are of much shorter duration.  Usually to have a longer term measurement of cardiovascular impacts retrospective studies are performed.  In addition, throughout the entire two years the variables in question were controlled in both groups

Ultimately sixty-one healthy middle-aged (45-64 years) individuals were chosen.  Anyone who reported a history of regular exercise was excluded.  Fifty-two subjects completed the study, 28 in the exercise group and 24 in the control group.  These numbers were determined to be large enough to make the results of the research statistically significant.  The subjects in the experimental group had a slow ramp up of their exercise volumes and intensities.  For the first month of the study the subjects in the experimental group performed three 30 minute cardio sessions per week at a base rate that was 1-20 beats below their maximum steady state heart rate.  In the second month 2 sessions were added where the subjects trained at their maximum steady state.  In month three a third session at maximum steady state was added.  In month 3 the subjects also began to perform high intensity intervals at 90-95% of their peak heart rate.  They performed a 4 minute interval followed by 3 minutes of recovery at 60-75% of peak heart rate.  Four rounds of the intervals were performed.  The day following high intensity intervals the subjects had a recovery day where they did 20-30 minutes of walking or light aerobic activity.

By month 6 the experimental group was training 5-6 days per week which included 2 interval sessions, 1 long training sessions of at least an hour and one 30 minute session at their base pace.  This program was maintained for 4 months.  At this point, after 10 months subjects were retested to adjust their training zones and they began a 14 month maintenance phase.  In this phase they only performed intervals 1 time per week.  The subjects were allowed to utilize different pieces of exercise equipment (bike, treadmill, elliptical, rower) or exercise outdoors (running, cycling, swimming) and were encouraged to perform different types of exercise to make the sessions fun and avoid injuries.  They were also instructed to perform strength training 2 times per week.

The control group was instructed to perform yoga, balance and strength training 3 times per week for the entire 2 years.  They were not allowed to perform any endurance exercise.  Both groups were closely monitored throughout the entire 2 years.

Results

Over the course of the first 10 months of the study the experimental group saw their maximum oxygen uptake (VO2max) increase by 18%.  This increase was then maintained over the following 14 months of the maintenance phase.  The control group actually saw their VO2max decrease by 1% over the course of two years as would be expected in untrained individuals as they get older.

Left ventricular end-diastolic volume (LVEDV) is a measure of the amount of blood that is in the left ventricle when it finishes its relaxation phase, right before it contracts.  More blood in the chamber means the surrounding heart muscle tissue is more pliable, stretching more to allow the increased volume.  This signifies a less stiff left ventricle and will result in higher stroke volumes because more blood is available to be pumped.  The experimental group saw a 17% increase in LVEDV over the initial 10 months of training.

Other direct measures of stiffness and pressure-volume relationships all showed a marked improvement in the experimental group.  The experimental group also saw a five beat drop in their resting heart rate while the control group did not experience any change.

Putting It All Together

The primary take away from this study is that 2 years of exercise for 30 minutes, 4 to 5 days a week including at least 1 day of higher intensity interval training results in significant reductions in left ventricle  and overall myocardial stiffness.  This can be directly related to decreases in the risks of cardiovascular disease.  This exercise protocol is exceptionally similar to recommendations offered by the American Heart Association and The American College of Sports Medicine.  Both promote 150 minutes of moderate exercise per week performed over 5 days per week for 30 minutes per day or vigorous exercise performed 3 days per week for at least 25 minutes.

The combination of low, moderate and high-intensity exercise also showed marked improvements in measures of fitness (VO2max and resting heart rate) that are also correlated with decreased cardiovascular risk.  The authors theorize that the higher intensity component of the program is a particularly powerful driver of the changes seen in these fitness related measures.

For those readers who have been riding their desk and sofa for far too long, the study also showed that these changes can take place in sedentary middle aged individuals and that this population does have the psychological capacity to adhere to a long term, regular exercise program.  If you haven’t been a lifelong athlete or regular exerciser there is now evidence that as an average middle-aged individual you can significantly improve the condition of your heart, lower your risk of heart disease and death and achieve higher levels of fitness.

Arbab-Zadeh, A., Dijk, E., Prasad, A., Fu, Q., Torres, P., Zhang, R., Thomas, J.D., Palmer, D. and Levine, B. (2004) Effect of Aging and Physical Activity on Left Ventricular Compliance, Circulation, Sep:110(13): 1799-1805

Bhella, P., Hastings, J., Fujimoto, N., Shibata, S., Carrick-Ranson, G., Adams-Huet, B. and Levine, B. (2014) Impact of Lifelong Exercise “Dose” on Left Ventricular Compliance and Distensibility. J Am Coll Cardiol. Sep 23: 64(12): 1257-1266

Fujimoto, N., Hastings, J., Bhella, P., Shibata, S., Gandhi, N., Carrick-Ranson, G., Palmer, D. and Levine, B. (2012) Effect of ageing on left ventricular compliance and distensibility in healthy sedentary humans. J Physiol. Apr 15: 590(pt 8): 1871-1880.

Howden, E., Sarma, S., Lawley, J., Opondo, M., Cornwell, W., Stoller, D., Urey, M., Adams-Huet, B. and Levine, B. (2018) Reversing the Cardiac Effects of Sedentary Aging in Middle Age-A Randomized Controlled Trial. Circulation. 117.030617. doi: 10.1161/CIRCULATIONAHA.117.030617. [Epub ahead of print]

Save Your Brain. Get Moving This Year.

Let’s start the New Year by looking at the impact of physical activity and exercise on brain health and function.  Maybe if we do things right at the end of this year we will still remember what we learned in today’s article.

We all have people we care about who are getting up there in years, and getting older is something that all of us have in common.  If you are like me and see someone in their 70’s or 80’s (or older) motoring by you on a walk or grinding it out in the gym  you think “wow, I want to be like them when I’m that age” or “I wish my parents were more like that”.  Maybe you flip on the TV or read an article and come across another older adult who just blows you away with how smart and aware and engaged they are.  Is regular physical activity part of the secret to their success?  Research is starting to strongly suggest that it is.

A study by Demnitz et at. (2017) titled Associations between Mobility, Cognition and Brain Structure in Healthy Older Adults attempted to tease out the relationships between these vital elements.  Mobility was measured with gait, balance and chair-stand tests.  Cognitive measures included executive function, memory and processing-speed.  For brain structure the authors looked at grey matter volume and white matter microstructures.

All three measures of mobility had positive associations with processing speed, so if you didn’t have to reread this to follow along maybe you’ve been moving around and getting up enough.  Better executive function was correlated with faster walking speeds.  Remember that executive function relates to your ability to plan, organize and complete tasks including managing your time, staying focused and regulating emotions.  If you decided that reading this blog was important, made time for it, searched it out and are still reading your executive function may be working well.  Unfortunately none of the measures in this study were associated with improved memory.

Better mobility was also found to be associated with increased grey matter volume while a chair stand test was found to be correlated with white matter integrity.  You don’t have to be a brain scientist to understand that maintaining the volume and integrity of your brain matters.

Demnitz et al. (2016) also conducted a meta-analysis of 26 studies that explored the relationship between mobility and cognition in healthy older adults.  The authors used gait, balance and lower extremity function as the measures of mobility.  For cognition they chose global cognitive function, memory, executive function and processing speed.

With regard to gait, speed was the most commonly measured aspect and positive relationships were found between gait and all aspects of cognitive function.  This corresponds with another systematic review by Morris et al. (2016) which established meaningful relationships between gait and global cognition and executive function.

Lower extremity function was measured with either a test of how many times someone can stand up from a chair without using their arms within a given time or standing up and walking a short distance then sitting back down for time.  Again all aspects of cognitive function showed positive relationships with better lower extremity function, most notably global cognition and executive function.  While there was less data regarding balance the research that does exist points to a positive relationship.

A meta-analysis by Santos-Lozano et al. (2016) found a 40% reduction in risk of developing Alzheimer disease for those that engaged in moderate to vigorous physical activity compared to those who were sedentary.  Tan et at. (2016) found relationships between higher levels of physical activity and brain volume as well an increased risk for dementia for those in the lowest quintile of physical activity as compared to those in the highest.

Want more evidence that physical activity helps preserve brain volume?  A study of 1449 middle-aged adults by Rovio et al. (2010) found that those who engaged in physical activity in midlife showed greater grey matter volume when measured 21 years later as opposed to those who where more sedentary.  In a study of 299 adults, Erickson et al. (2010) found that increased physical activity in the form of walking positively correlated with increased grey matter volume 9 years later and that increased grey matter volume reduced the risk of cognitive impairment by 2-fold.  Bugg and Head (2009) also found that subjects who engaged in more physical activity had higher frontal region brain volumes and that age-related atrophy of the medial temporal lobe was significantly reduced compared to those who engaged in low levels of physical activity.  There are so many studies showing a relationship between physical activity and neuro-protective effects that to type all of them out would almost give me a day’s worth of brain preservation.  (For those of you not regularly exercising and suffering brain atrophy that is a joke, you can not consider typing on your computer physical activity. I’m limiting how many examples I give so as not to bore you to death and so I can get up and move instead.)

As always we must remember there are limitations to all of these studies and we must be careful not to over-interpret any of the results.  Among the factors that can impact the studies are issues regarding which tests are conducted, how the results are measured, how appropriate those test and measurements are to get the ultimate question of what relationship exists between the variables in question, the number of subjects, gender, age, health and to what extent cognitive issues led to the decline in mobility as opposed to increased or decreased mobility impacting cognition.  All of that being said, there are enough studies available to strongly suggest that a relationship between mobility and cognitive function does exist.  We only reviewed a small sample of the research in this area.

Now what does all of this mean for today’s strength/conditioning/fitness professional working with older adults or just the average person reading this who is concerned about their future brain function?  Certainly we can impact lower extremity function by training lower body and core strength.

Improving squat, deadlift, lunge and step-up patterns in terms of neurological control/coordination as well as basic strength will certainly have carry over effects to overall lower body function.  You don’t have to put a barbell on someone’s back or move heavy weight to significantly impact lower extremity strength in older and untrained individuals.  Body weight and light weights will have plenty of impact.  Yes we are always thinking of improvement but you need to take into account the realities of the person in question.  Very slow and small changes add up over time if you can establish consistency.  And let’s face it; consistency is often the number one battle.

Perhaps you or your client has injuries or significant limitations in function.  That only makes this all the more important.  Yes you might have to change the exercises but there are plenty of work-arounds.  If a back or knee injury limits squat and deadlift patterns to no more than body weight or with limited range of motion those body weight movements still matter and you can supplement them with other exercises such as sled pushes which require tremendous hip drive.  While I don’t rely on machines that often they can still be useful and shouldn’t be forgotten.  That leg extension or seated leg curl may have a place in a program.

As for improving gait there may be basic foot strike patters such as walking through the big toe that need to be addressed but more than anything the key to better gait, including improvements in speed and cardio-respiratory fitness for older adults is walking more.  No equipment necessary besides a good pair of sneakers.

So there you have it.  Just a tiny sampling of the research on brain health and movement.  One more reason to get up from the computer or off the sofa and take a walk or do a few sets of squats.

Bugg, J. and Head, D. (2011) Exercise moderates age-related atrophy of the medial temporal lobe. Neurobiology of aging. March, 32(3): 506-514.

Demnitz, N., Esser P., Dawes, H., Valkanova, V., Johansen-Berg, H., Ebmeier, KP. and Sexton, C.  (2016) A systematic rewiew and meta-analysis of cross-sectional studies examining the relationship between mobility and cognition in healthy older adults.  Gait Posture, Oct, 50:164-174. 

Demnitz, N., Zsoldos, E., Mahmood, A., Mackay, CE., Kivimaki, M., Singh-Manoux, A., Dawes, H., Johansen-Berg, H., Ebmeier, KP. and Sexton, CE.  (2017)  Associations between Mobility, Cognition and Brain Structure in Healthy Older Adults, Front. Aging Neurosci.,  May 23,  

Erickson, K.I., Raji, C.A., Lopez, O.L., Becker, J.T., Rosano, C., Newman, A.B., Gach, H.M., Thompson, P.M., Ho, A.J. and Kuller, L.H. (2010) Physical activity predicts grey matter volume in late adulthood. Neurology, Oct, 75(16):1415-1422

Morris, R., Lord, S., Bunce, J., Burn, D. and Rochester, L. (2016) Gait and cognition: Mapping the global and discrete relationships in ageing and neurodegenerative disease. Neurosci Biobehav Rev., May, 64:326-45.

Santos-Lozano, A., Pareja-Galeano, H., Sanchis-Gormar, F., Quindos-Rubial, M., Fiuza-Luces, C., Cristi-Montero, C., Emanuele, E., Garatachea, N. and Lucia, A. (2016) Physical Activity and Alzheimer Disease: A Protective Association. Mayo Clinic Proceedings, August 91(8): 999-1020.

Rovio, S., Spulber, G., Nieminen, LJ., Niskanen, E., Winblad, B., Tuomilehto, J., Nissinen, A., Soininen, H. and Kivipelto, M. (2010) The effect of midlife physical activity on structural brain changes in the elderly. Neurobiol Aging, Nov, 31(11):1927-1936.

Tan, ZS., Spartano, NL., Beiser, AS., DeCarli, C., Auebach, SH., Vasan RS. and Seshardi, S. (2017) Physical Activity, Brain Volume, and Dementia Risk: The Framingham Study.  J Gerontol A Biol Sci Med Sci. June 1, 72(6):789-795.