The aging of elite male athletes: age-related changes in performance and skeletal muscle structure and function

Abstract

Objective: The paper addresses the degree to which the attainment of the status as an elite athlete in different sports ameliorates the known age-related losses in skeletal muscle structure and function.

Design: The retrospective design, based on comparisons of published data on former elite and masters athletes and data on control subjects, assessed the degree to which the attainment of elite and masters athlete status ameliorated the known age-related changes in skeletal muscle structure and function.

Setting: Institutional.

Participants: Elite male athletes.

Interventions: Participation in selected individual and team sports.

Main outcome measurements: Strength, power, VO2max, and performance.

Results: For elite athletes in all sports, as for the general population, age-related muscle atrophy begins at about 50 years of age. Despite the loss of muscle mass, elite athletes who maintain an active lifestyle age gracefully with few health problems. Conversely, those who lapse into inactivity regress toward general population norms for fitness, weight control, and health problems. Elite athletes in the dual and team sports have careers that rarely extend into their 30s.

Conclusions: Lifelong physical activity does not appear to have any impact on the loss in fiber number. The loss of fibers can be buffered to some degree by hypertrophy of fibers that remain. It is surprising that the performance of elite athletes in all sports appears to be impaired before the onset of the fiber loss. Even with major losses in physical capacity and muscle mass, the performance of elite and masters athletes is remarkable.

Figure 1

The relationships between the number of motor units in the extensor digitorum brevis muscles and the age of men between five and 88 years of age (solid line) and between the total number of fibers in the vastus lateralis muscles and the age of the cadavers between18 to 82 years of age (dashed line). The number of motor units remained constant from 5 years to 50 years of age, but then decreased linearly with a zero intercept at ninety-five years of age (modified from Campbell et al., 1973 with permission). Similarly, the average number of fibers in the vastus lateralis muscle did not change between 18 and 50 years of age, but by age 80, the mean number of fibers decreased to 50% of the number for younger men (modified from Lexell et al., 1988 with permission).

Figure 2

The isometric knee strengths for untrained control subjects (solid line) and for elite Masters weight-lifters (dashed line) from 40 to 88 years of age were obtained from Pearson et al., 2002 with permission. Note: Surprisingly, the isometric knee strength of the untrained control subjects did not decrease with age, whereas the weight-lifters showed a decline.

Figure 3

The peak power for untrained control subjects (solid line) and for elite Masters weight-lifters (dashed line) from 40 to 88 years of age were obtained from Pearson et al., 2002 with permission. Note that for peak power both untrained control subjects and the elite Masters weight-lifters showed declines in peak power with age, with the slope for the weight-lifters greater than that of the control subjects.

Figure 4

VO_2max of sedentary non-athletes and endurance-trained elite runners of various ages were obtained from Heath (59) and Pollock (19). Note the gradual conversion of the VO_2max of an endurance-trained elite runner to that of a sedentary non-athlete over time as a result of the cessation of run-training (Pollock et al., 1997, with permission; Robinson et al., 1976, with permission).

Figure 5

The performances of Masters athletes for the Marathon run and for weight-lifters for the ‘clean & jerk’. The data for the marathon run were taken from the Alan L. Jones website [http://home.stny.rr.com/alanjones/AgeGrade.html] “Age graded running races” 2006. The Masters weight-lifting data was obtained from IWF Masters Records [http://www.iwfmasters.net/records/iwf-men.pdf] December 2006 (men’s weight class 85 kg., clean & jerk).

Figure 6

Average statistics for three basketball players; Kareem Abdul-Jabbar, Charles Barkley and Michael Jordan for the number of points per game (PPG) and for free throw percentage each expressed as a percentage of the highest value achieved during the players’ careers. Note the consistency of the free throw percentage for each of the three players compared with the declining values for points per game (see text for explanation). Data were obtained from the nba.com website [http://www.nba.com].

Figure 7

Schematic diagram of the sequence of events for a typical muscle fiber within a skeletal muscle exposed to a severe lengthening contraction protocol. The damaged fibers would be scattered throughout the injured muscle both singly and in small clusters. Each damaged fiber goes through this sequence of events, with full recovery of fibers in young animals complete within a few weeks and those in old animals requiring up to a month with the possibility of permanent damage (reproduced from Rader et al., 2006).