Impact of weather on marathon-running performance.
ABSTRACT Marathon running performance slows in warm weather conditions, but the quantitative impact of weather has not been established.
To quantify the impact of weather on marathon performance for different populations of runners.
Marathon results and weather data were obtained for the Boston, New York, Twin Cities, Grandma's, Richmond, Hartford, and Vancouver Marathons for 36, 29, 24, 23, 6, 12, and 10 yr, respectively. The race results were broken into quartiles based on the wet-bulb globe temperature (Q1 5.1-10 degrees C, Q2 10.1-15 degrees C, Q3 15.1-20 degrees C, and Q4 20.1-25 degrees C). Analysis of the top three male and female finishers as well as the 25th-, 50th-, 100th-, and 300th-place finishers were compared with the course record and then contrasted with weather.
Marathon performances of top males were slower than the course record by 1.7 +/- 1.5, 2.5 +/- 2.1, 3.3 +/- 2.0, and 4.5 +/- 2.3% (mean +/- SD) for Q1-Q4, respectively. Differences between Q4 and Q1, Q2, and between Q3, and Q1 were statistically different (P < 0.05). The top women followed a similar trend (Q1 3.2 +/- 4.9, Q2 3.2 +/- 2.9, Q3 3.8 +/- 3.2, and Q4 5.4 +/- 4.1% (mean +/- SD)), but the differences among quartiles were not statistically significant. The 25th-, 50th-, 100th-, and 300th-place finishers slowed more than faster runners as WBGT increased. For all runners, equivalence testing around a 1% indifference threshold suggests potentially important changes among quartiles independently of statistical significance.
There is a progressive slowing of marathon performance as the WBGT increases from 5 to 25 degrees C. This seems true for men and women of wide ranging abilities, but performance is more negatively affected for slower populations of runners.
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ABSTRACT: We investigated age and performance in distance-limited ultra-marathons held from 50 km to 1,000 km. Age of peak running speed and running speed of the fastest competitors from 1969 to 2012 in 50 km, 100 km, 200 km and 1,000 km ultra-marathons were analyzed using analysis of variance and multi-level regression analyses. The ages of the ten fastest women ever were 40 ± 4 yrs (50 km), 34 ± 7 yrs (100 km), 42 ± 6 yrs (200 km), and 41 ± 5 yrs (1,000 km). The ages were significantly different between 100 km and 200 km and between 100 km and 1,000 km. For men, the ages of the ten fastest ever were 34 ± 6 yrs (50 km), 32 ± 4 yrs (100 km), 44 ± 4 yrs (200 km), and 47 ± 9 yrs (1,000 km). The ages were significantly younger in 50 km compared to 100 km and 200 km and also significantly younger in 100 km compared to 200 km and 1,000 km. The age of the annual ten fastest women decreased in 50 km from 39 ± 8 yrs (1988) to 32 ± 4 yrs (2012) and in men from 35 ± 5 yrs (1977) to 33 ± 5 yrs (2012). In 100 km events, the age of peak running speed of the annual ten fastest women and men remained stable at 34.9 ± 3.2 and 34.5 ± 2.5 yrs, respectively. Peak running speed of top ten runners increased in 50 km and 100 km in women (10.6 ± 1.0 to 15.3 ± 0.7 km/h and 7.3 ± 1.5 to 13.0 ± 0.2 km/h, respectively) and men (14.3 ± 1.2 to 17.5 ± 0.6 km/h and 10.2 ± 1.2 to 15.1 ± 0.2 km/h, respectively). In 200 km and 1,000 km, running speed remained unchanged. In summary, the best male 1,000 km ultra-marathoners were ~15 yrs older than the best male 100 km ultra-marathoners and the best female 1,000 km ultra-marathoners were ~7 yrs older than the best female 100 km ultra-marathoners. The age of the fastest 50 km ultra-marathoners decreased across years whereas it remained unchanged in 100 km ultra-marathoners. These findings may help athletes and coaches to plan an ultra-marathoner's career. Future studies are needed on the mechanisms by which the fastest runners in the long ultra-marathons tend to be older than those in shorter ultra-marathons.SpringerPlus 11/2014; 3:693. DOI:10.1186/2193-1801-3-693
Conference Paper: Exercise science: research to sustain and enhance performance[Show abstract] [Hide abstract]
ABSTRACT: Cardiovascular adjustments accompanying exercise in high ambient temperatures are likely responsible for diminished aerobic capacity and performance in such conditions. These adjustments include a phenomenon known as cardiovascular drift in which heart rate rises and stroke volume declines progressively over time during constant-rate exercise. A variety of factors modulate the magnitude of cardiovascular drift, e.g., elevated core and skin temperatures, dehydration, and exercise intensity. Regardless of the mode of manipulation, decreases in stroke volume associated with cardiovascular drift result in directionally and proportionally similar decreases in maximal aerobic capacity. Maximal aerobic capacity is determined by maximal heart rate, maximal tissue oxygen extraction, and maximal stroke volume. Because maximal heart rate and maximal tissue oxygen extraction are unaffected during exercise in the heat, decreased stroke volume associated with cardiovascular drift likely persists during maximal efforts and explains the decrease in maximal aerobic capacity. Decreased maximal aerobic capacity results in a greater perceptual and physiological strain accompanying any given level of work. Therefore, sustaining and enhancing performance involves sophisticated monitoring of physiological strain combined with development of countermeasures that mitigate the magnitude of deleterious phenomena like cardiovascular drift.SPIE Defense, Security, and Sensing; 05/2013
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ABSTRACT: Anecdotal reports have assumed that women would be able to outrun men in long-distance running. The aim of this study was to test this assumption by investigating the changes in performance difference between sexes in the best ultramarathoners in 50-mile, 100-mile, 200-mile, 1,000-mile, and 3,100-mile events held worldwide between 1971 and 2012. The sex differences in running speed for the fastest runners ever were analyzed using one-way analysis of variance with subsequent Tukey-Kramer posthoc analysis. Changes in sex difference in running speed of the annual fastest were analyzed using linear and nonlinear regression analyses, correlation analyses, and mixed-effects regression analyses. The fastest men ever were faster than the fastest women ever in 50-mile (17.5%), 100-mile (17.4%), 200-mile (9.7%), 1,000-mile (20.2%), and 3,100-mile (18.6%) events. For the ten fastest finishers ever, men were faster than women in 50-mile (17.1%±1.9%), 100-mile (19.2%±1.5%), and 1,000-mile (16.7%±1.6%) events. No correlation existed between sex difference and running speed for the fastest ever (r (2)=0.0039, P=0.91) and the ten fastest ever (r (2)=0.15, P=0.74) for all distances. For the annual fastest, the sex difference in running speed decreased linearly in 50-mile events from 14.6% to 8.9%, remained unchanged in 100-mile (18.0%±8.4%) and 1,000-mile (13.7%±9.1%) events, and increased in 3,100-mile events from 12.5% to 16.9%. For the annual ten fastest runners, the performance difference between sexes decreased linearly in 50-mile events from 31.6%±3.6% to 8.9%±1.8% and in 100-mile events from 26.0%±4.4% to 24.7%±0.9%. To summarize, the fastest men were ~17%-20% faster than the fastest women for all distances from 50 miles to 3,100 miles. The linear decrease in sex difference for 50-mile and 100-mile events may suggest that women are reducing the sex gap for these distances.Open Access Journal of Sports Medicine 01/2015; 6:7-21. DOI:10.2147/OAJSM.S76490