Inactivity may be a greater factor in insulin resistance than aging

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[lef.org]

 

Inactivity may be a greater factor in insulin resistance than aging

 

An article entitled, " Endurance exercise as a countermeasure for aging, "

published online on August 20, 2008 in the journal Diabetes, concluded

that the reduction in insulin sensitivity that often occurs in one's

later years may not be an inevitable consequence of aging.

Researchers at the Mayo Clinic College of Medicine in Rochester,

Minnesota sought to determine whether long-term endurance training could

improve lowered insulin sensitivity (a factor in the metabolic syndrome,

which is more prevalent with aging) and mitochondrial dysfunction, a

widespread condition of aging which has been associated with declines in

insulin sensitivity. (Mitochondria are organelles within the cell that

produce energy.) The team enrolled 22 adults aged 18 to 30 years, and 20

adults between the ages of 59 to 76 years for the current study.

Participants were divided into those who reported less than 30 minutes

of exercise per day two times weekly, and those who participated in at

least one hour of running or cycling per day six days per week over the

past four years. Blood samples were tested for lipids, glucose, and

other factors, and dual x-ray absorptiometry was used to measure fat and

fat free mass. Insulin sensitivity, whole-body peak oxygen uptake,

muscle mass, mitochondrial function, and SIRT3 expression were also

measured. SIRT3 is a mitochondrial gene of the sirtuin family that has

been linked with longevity, whose expression has been found to increase

with calorie restriction.

 

Getting the most from exercise

 

Exercise has been shown to increase life span by an average of one to

four years for people who engage in moderate to difficult exercise

routines (Jonker JT et al 2006; Franco OH et al 2005). Better yet, those

additional years will be healthful years because exercise benefits the

heart, lungs, and muscles. Even moderate levels of exercise have been

documented to stave off many dreaded diseases of aging. Walking briskly

for 3 hours per week reduces one's chances of developing many chronic

health problems (Chakravarthy MV et al 2002). Exercise may also

alleviate depression and enhance self-image and quality of life (Elavsky

S et al 2005; Schechtman KB et al 2001).

 

There are many benefits to a program of regular exercise. In addition to

enhanced self-esteem, exercise can promote weight loss and aid in the

prevention of a number of diseases, including heart disease and

diabetes. In addition, the following nutrients have been shown to

enhance muscle function, promote quicker recovery after exercise, and

increase strength:

 

Carnitine—1000 to 2000 milligrams (mg) daily

 

Carnosine—1500 to 3000 mg daily

 

Branched-chain amino acids—containing at least 1200 mg L-leucine, 600

mg

 

L-isoleucine, and 600 mg L-valine

 

Glutamine—500 to 1000 mg daily

Whey protein—consider taking 20 to 80 grams (g) whey protein daily. It

is most important to consume whey protein before and immediately after

your exercise session to make sure adequate protein is available to

depleted muscles.

 

PPC—900 to 1800 mg