Performance, training and lifestyle parameters of marathon runners aged 20-80 years: results of the PACE-study.

Successful finishing of marathon requires regular endurance training and appropriate lifestyle. Thus, marathon running times and training data from large samples of physically active and fit elderly are ideal for the assessment of age-related performance. In the present study we analyzed 439 278 running times from result lists of 108 marathon competitions and data from a survey via internet questionnaire about training and behavioural factors of marathon finishers. Marathon times and 6 992 data sets from the internet questionnaire were separated into groups based on age and sex and analyzed by two-way ANOVA. Our main findings are that 1) there are virtually no relevant running time differences (p<0.01) in marathon finishers from 20 to 55 years and 2) the majority of middle-aged and elderly athletes have training histories of less than seven years of running. With the exception of marathon running times we did not encounter any significant gender related differences (p>0.01). The present findings strengthen the concept that considers aging as a biological process that can be considerably speeded up or slowed down by multiple lifestyle related factors.

Age-related changes in marathon and half-marathon performances.

We examined age-related changes in endurance performance of marathon and half-marathon finishers. A total of 405 515 running times were separated into groups based on age, sex, and distance. After exclusion of repetitive running times, 300 757 runners were analyzed by ANOVA (factors: age, sex). For each age group (six decades, 20-79 years), mean running times for all finishers, as well as top-ten performers, were assessed. As expected, age and sex had significant influence on running times. Female running times were about 10 % (marathon) and 13 % (half-marathon) above the corresponding times of their age-matched peers. The main finding is that in our sample of trained subjects significant age-related losses in endurance performance did not occur before the age of 50 years. Mean marathon and half-marathon times were virtually identical for the age groups from 20-49 years. Moreover, age-related performance decreases (p < 0.01) of the 50 - 69-year-old subjects were only in the range of 2.6 - 4.4 % per decade. These results suggest that the majority of older athletes are able to maintain a high degree of physical plasticity. The hypothesis that lifestyle factors have considerably stronger influences on functional capacity than the factor age is also supported by these findings from physically active and fit elderly.

Maximal manual stretcher carriage: performance and recovery of male and female ambulance workers.

The effects of a maximal duration stretcher carriage on heart rate (HR), lactate concentration, hand steadiness and hand-grip strength were studied up to 72 h post-exercise in 17 male and 15 female military ambulance personnel. Using both hands for transport, the participants walked on a treadmill ergometer at a speed of 4.5 km/h. Force measurements at the handlebars yielded mean loads of 245 N (25 kg) on each side. Each step on the treadmill induced additional force oscillations with peak forces up to 470 N corresponding to 130% (women) and 98% (men) of maximal voluntary contraction (MVC). In the males the maximal transport time was about twice the time in women (mean +/- SD: 184 +/- 51 s vs. 98 +/- 34 s). These differences had no significant effect on HR and lactate values. The same applies to hand steadiness, which showed only a transient deterioration immediately after exercise. In contrast to these parameters, substantial differences were seen in hand-grip strength recovery. Immediately after exercise, maximal hand-grip strength decreased by 150 N (25% MVC) in the males vs. 50 N (14%) in the females. Irrespective of gender, individuals with larger hand-grip strength and longer carriage durations (range 120 s-280 s) showed the slowest strength recoveries (up to 72 h) as compared to 1 h of recovery in participants with short transport durations (range 27 s-120 s). These findings suggest that the increasing number of eccentric strains during uninterrupted stretcher carriage induces cumulative muscle damages that may require some days for complete recovery.

Recovery of hand grip strength and hand steadiness after exhausting manual stretcher carriage.

Rescue activities frequently require not only substantial and sustained hand-grip forces but also a subtle coordination of hand and finger muscles, e.g. when manipulating injection syringes after manual stretcher carriage. We investigated the recovery kinetics of manual coordination and muscle strength after exhausting stretcher carriage (4.5 km/h, load at each handle bar: 25 kg). Hand steadiness (frequency and duration of wall contacts when holding a metal pin into a small bore) and parameters of hand-grip strength were determined in 15 male volunteers before and immediately after the stretcher carriage. Measurements were repeated after 0.5, 1, 4 and 24 h of recovery. Mean carrying time was 215+/-87 s (SD), mean transport distance amounted to 264+/-104 m. During the carriage test, forces at the stretcher handles oscillated in the order of +/-50 N within each gait cycle. Immediately after exhaustion, hand steadiness was significantly deteriorated (threefold increase in frequency and duration of wall contacts), maximum and mean hand-grip force over 15 s were reduced by almost 20%. While the recovery of hand steadiness was complete by minute 30 after stretcher carriage, a significant reduction in maximum and mean hand-grip force by 12% could still be observed after 24 h. The present findings demonstrate that hand steadiness recovers much faster than maximum hand-grip strength after exhaustive manual stretcher carriage (less than 30 min vs. more than 24 h). Probably, muscle damage induced in particular by the eccentric components during stretcher transport seems to affect only the generation of large forces. By contrast, the generation and coordination of the much lower forces required for hand-steadiness appears to be impaired only during the short transient of metabolic recovery.