Posts in Exercise
Exercise Shown To Make The Body's Cells Younger

Aerobic exercise has been shown to improve our current mental, emotional, and physical health. In addition, aerobically trained individuals experience significant health benefits including decreased risk of chronic disease and premature death compared to their sedentary peers. In addition to these health benefits, scientists are also researching the impact of exercise on the aging process. New research is discovering exercise impacts aging at the cellular level. Scientists often measure a cell’s age by the length of the tip, telomere, of its’ chromosomes. Shorter chromosome length is associated with cellular dysfunction and cell death, but this length is modifiable through environment factors including exercise. A recent study examined the impact of exercise on chromosome and telomere length.

Werner and colleagues enrolled 124 inactive participants and randomized them into one of four groups including control, aerobic training, interval aerobic training, or resistance training (Eur Heart J. 2018). Both exercise groups attended 3, 45 minute training sessions per week over the 6 month training period. Authors reported aerobic capacity, VO2 max, increased in the exercise groups but only the aerobic training group impacted the individual’s chromosomes. Aerobic training was shown to lengthen telomeres on the ends of chromosomes after the training period. Authors reported the length changes were important for a cell’s regenerative ability and healthy aging.

Older Cyclists Maintain Immune System Function Vs. Sedentary Peers

Previous research reports older adults who remain active are able to slow the physiological effects of aging including increased body fat, decreased muscle mass, and muscle weakness.  Other systems in our body also show a decline with aging including the immune system.  Immunesenescence, the decline in immune system function due to aging, is an established fact with a decline of 2-3% each year beginning in our 20s.  A new study highlights the benefits of aerobic exercise on immune system function in older adults.

Duggal and colleagues studied 125 active older adults (55-79 years of age) to determine the impact of exercise on immune system function (Aging Cell. 2018).  The authors compared the immune function of these older cyclists to their sedentary peers.  Surprisingly, the older cyclists demonstrated immune functions comparable to 20 and 30 year old individuals.  Specifically, in T cell levels which help the body respond to infections.  The active adults showed less signs of decreased immune system function.  This is the first study to show the positive effects of aerobic exercise on immune system function.

Higher Intensity Exercise Leads to Greater Disease Risk Reductions

Colorado remains one of the fittest states in the Colorado with low rates of obesity, diabetes, heart disease, and other diseases associated with low activity levels.  Specifically, our home town of Boulder remains of the fittest cities in the country due to its' high percentage of citizens who meet or exceed the U.S. Surgeon General's recommendations on daily exercise.  

A MET minute is the intensity of the exercise multiplied by its' duration.  For example, light exercise is 1-3 METs where as vigorous activity is 6 or greater METs.  600 MET minutes per week could be either long duration light to moderate activity or a lesser duration of high intensity exercise.  These established guidelines were based off of epidemiological research showing the positive impact of aerobic exercise on risk reduction for many diseases including stroke, heart disease, diabetes, and cancer.   New research is now showing a further reduction in disease risk if individuals exceed these weekly guidelines by exercising longer and harder.  

A recent review article in the British Medical Journal quantified the dose response of exercise duration and intensity on disease risk modification (Kyu et al. 2016).  The authors reviewed 174 articles on exercise's impact on disease.  In general, the authors found more active participants were at lower risk of many diseases (see above), but those were more active showed even greater reductions in disease risk.  Thus, it appears there is further benefit to exercising at a higher intensity and/or longer duration to further reduce disease risk.  Individuals are advised to speak with their Physician and Physical Therapist before engaging in any vigorous exercise program. 


Weakened Foot Strength and Orthotic Use in Patients with Heel Pain

In our previous posts we have documented the weakness and atrophy of the foot's "core" muscles among patients with heel pain.   Heel pain is one of the most common foot and ankle diagnoses we see in our Boulder Physical Therapy Practice.  This condition is commonly treated with manual therapy and exercises targeting the lower quarter.  A targeted area for exercise involves the foot's core muscles which contribute to stability and function of our arch.  Without adequate strength and control of the arch we are more at risk for conditions such as heel pain and plantar fasciitis.  Recent research highlights the importance of these muscles and the negative impact foot orthoses may have on their function. 

McClinton and colleagues studies 27 patients with heel pain compared to matched peers who ddi not have any heel pain (JOSPT 2016).  Participants' foot strength was tested using two clinical tests for foot "core" strength.  Not surprisingly, the patients with heel pain had significantly less foot strength than their asymptomatic peers.  Interestingly, longer use of foot orthoses was associated with lower performance on these strength measurements.   Stabilization of the arch with foot orthotics may weaken the foot's core muscles because they prevent these muscles from performing their natural function.  

Patient's are encouraged to contact their local PT on the most appropriate treatments for their heel and foot pain.  

Improving Athletic Performance in Adolescents

Resistance training is an essential part of any training program due to its' ability to reduce injury risk and improve sports performance.  Adolescents can safely resistance train if they are properly supervised and can perform movements correctly.  One of the foundations of any strengthening program is the squat.  The squat is an incredible training tool for the development of strength, speed, and sports performance.  This exercise focuses on the transfer of forces and weight in a vertical direction where as a newer exercise, the hip thrust, focuses on the transfer of forces in a horizontal direction.  This second exercise may be best for sports requiring horizontal transfer of forces such as sprinting.  

Contreras and colleagues studied these two exercises to determine which strengthening exercise showed the greatest improvement in adolescent performance (J Strength Conditioning Research 2016).  The authors randomized 28 adolescent athletes (14-17) to either a front squat or hip thrust training program, twice per week for 6 weeks.  Athletes were tested both before and after the training program on a battery of athletic performance tests including sprinting, jumping, and strength testing.  At the conclusion of 6 weeks, the athletes who performed the hip thrust training program showed beneficial effects on the sprint times indicating the exercise may be a helpful addition to strength programs for horizontal movement athletes (football, sprinting).

Athletes are encouraged to work with a local Physical Therapist to determine the most important exercises for their strength training program to reduce injury risk and improve performance. 

Injections for Knee Osteoarthritis

Knee osteoarthritis is a common condition in aging adults leading to pain and reduced performance of daily and recreational activities.  Manual therapy and exercise remain a hallmark of conservative care for this condition and have been shown to delay or prevent the need for a total knee replacement.  In addition to exercise, corticosteroid injections are often proposed to patients in order to reduce pain and improve patient participation.  A recent study in the Journal of the American Medical Association examined the impact of these injections in patients with knee arthritis.

Henriksen and colleagues studied 100 patients and randomized them to either a corticosteroid injection or a placebo injection prior to undergoing Physical Therapy 3 days a week for 12 weeks.  These patients all had evidence of knee arthritis on x ray and reported pain with daily activities including walking.  All patients improved through the course of the study, but no significant differences were noted at 2, 14, or 26 weeks between the group receiving a corticosteroid injection or a placebo.   The authors concluded there was no additional clinical benefit of a steroid injection and Physical Therapy compared to Physical Therapy alone.  Thus, Physical Therapy was the main reason for the patient's improvement.   

Patients with knee osteoarthritis are encouraged to seek out a local Physical Therapist to implement an effective rehabilitation program.