AGING AND THE OLDER ATHLETEAGING AND THE OLDER ATHLETE

CHAPTER 17CHAPTER 17

Learning Objectives

Compare the changes in strength and endurance records with aging.

Learn what cardiorespiratory changes occur with aging and the effects of training on these changes.

Discover what changes occur to muscles with aging and how these changes affect athletic performance.

(continued)

Learning Objectives

Find out how training affects biological aging and learn the differences in aging and physical activity.

Learn the effects of aging and training on body composition.

Discover the trainability of older athletes for strength and endurance.

VOLUNTARY PHYSICAL ACTIVITY IN RATS

Did You Know…?

Since physical activity tends to decline substantially as we age, distinguishing between the effects of aging and those of reduced physical activity is difficult when studying lifelong changes in physiological function.

CHANGES WITH AGE IN RUNNING RECORDS

CHANGEs WITH AGE IN SWIMMING RECORDS

CHANGES WITH AGE IN POWER-LIFTING RECORDS

Key Points

Running, swimming, cycling, and weight-lifting records indicate that we are in our prime during our 20s and early 30s.

Some swimmers have seen their best swimming performances in their 40s and 50s; this is often attributed to improvements in swimming technique, skill, and endurance.

Sports Performance and Aging

Performance generally declines with aging beyond our prime, primarily due to decrements in muscular and cardiovascular endurance and strength.

Cardiorespiratory Endurance and Aging

Central and peripheral circulation decrease

Aerobic capacity decreases about 1% per year

Maximum heart rate decreases

Stroke volume decreases

Cardiac output decreases

Changes in VO2max Among Normally Active Men

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25 47.7

35 43.1 -9.6

45 39.5 -17.2

52 38.4 -19.5

63 34.4 -27.7

75 25.5 -46.5

-1 -1. .Age VO2max % change from

(years) (ml kg min ) 25 years

Did You Know…?

Comparing per unit of body weight might not accurately measure decline in VO2max because we tend to gain weight as we age, which falsely lowers the VO2max per unit of body weight and because these values do not account for a person's initial VO2max. Comparisons should be based on the percentage change in VO2max in L/min.

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Studies of Older Athletes

There are individual differences in the rate of decline with aging.

Prior training offers little advantage to endurance capacity later in life unless you stay active.

Aging alone may not necessarily decrease VO2max..

When you keep intensity and volume of training high, your rate of decrease in SV and VO2max with aging slows, especially between ages 30 and 50 and less so after age 50.

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PERCENT CHANGE IN VO2MAX.

CHANGES IN VO2MAX WITH AGE.

Respiratory Changes With Aging

Vital capacity (VC) and forced expiratory volume in 1 s (FEV1.0) decrease linearly

Residual volume (RV) increases

Total lung capacity (TLC) remains unchanged

RV:TLC increases (less air can be exchanged)

Elasticity in lung tissue and chest walls decreases

VEmax decreases after maturity.

Key Points

Endurance training in middle and older age reduces the loss of elasticity from the lungs.

The pulmonary ventilation capabilities of endurance-trained athletes are only slightly decreased with aging.

Respiratory Aging and Performance

Arterial oxygen saturation does not decrease during strenuous exercise for normally active older adults.

Limitations in oxygen transport to the muscles and a decreased a-vO2 diff are the main causes for reduced VO2max.

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Did You Know…?

Maximal heart rate can be estimated with the following equation:

HRmax = 220 – age

However this estimates an average value for a given age; individual HRmax can vary by ±20 beats per minute or more.

Key Points

HRmax decreases due to decrease sympathetic nervous system activity and changes in cardiac conduction.

SVmax decreases due to increased total peripheral resistance and decreased left ventricular contractility.

Cardiovascular Changes With Aging

Qmax decreases due to decreased HRmax and SVmax.

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VO2max decreases due to reduced blood flow to active tissues and reduced Qmax.

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CARDIOVASCULAR EFFECTS OF AGING

LEG BLOOD FLOW AND AGING

Did You Know…?

Aging alone might decrease cardiorespiratory less than the deconditioning that occurs with inactivity, decreased activity, or decreased intensity of training. If body composition and physical activity are kept constant, VO2max decreases only 2% to 5% per decade, rather than the 10% per decade normally attributed to aging.

Strength Changes With Aging

Maximal strength decreases

Muscle mass decreases

Percentage of ST muscle fibers increases

Total number and size of muscle fibers decreases

Nervous system response slows

Little change in oxidative enzyme capacity or number of capillaries

CHANGES IN STRENGTH WITH AGING

MUSCLE FIBER CHANGES WITH AGING

Did You Know…?

While endurance training does not prevent the aging loss in muscle mass, strength or resistance training can maintain or increase the muscle fiber cross-sectional area in older men and women.

Key Points

The capacity to perform normal activity at high altitude is not reduced with aging.

Aging might provide some protection against the symptoms of acute altitude sickness, HAPE, and HACE.

Environmental Stress and Aging

The ability to adapt to exercise in the heat is reduced due to reduced sweat production with aging.

Body Composition and Aging

Relative body fat increases after maturity due to

Increased dietary intake

Decreased physical activity

Reduced ability to mobilize fat

After age 30, fat-free mass decreases due to

Decreased muscle mass

Increased bone mineral loss

Decreased physical activity

RELATIVE BODY FAT

VARIATIONS IN FAT, WEIGHT, AND FAT-FREE MASS

Did You Know…?

Physical training can help offset age-related changes in body composition.

Trainability of the Older Athlete

Endurance exercise

Produces similar gains in healthy people regardless of their age, sex, or initial fitness level

Produces greater improvement in muscle oxidative enzyme activities than in younger endurance-trained athletes

Resistance exercise

Produces increases in muscle strength and muscle hypertrophy