Effects of Altitude on Performance of Elite Track-and-Field Athletes

2015 ◽  
Vol 10 (7) ◽  
pp. 881-887 ◽  
Author(s):  
Michael J. Hamlin ◽  
Will G. Hopkins ◽  
Stephen C. Hollings

Purpose:Lower barometric air pressure at altitude can affect competitive performance of athletes in some sports. Reported here are the effects of various altitudes on elite track-and-field athletes’ performance.Methods:Lifetime track-and-field performances of athletes placed in the top 16 in at least 1 major international competition between 2000 and 2009 were downloaded from the database at tilastopaja.org. There were 132,104 performances of 1889 athletes at 794 venues. Performances were logtransformed and analyzed using a mixed linear model with fixed effects for 6 levels of altitude and random quadratic effects to adjust for athlete age.Results:Men’s and women’s sprint events (100–400 m) showed marginal improvements of ~0.2% at altitudes of 500–999 m, and above 1500 m all but the 100- and 110-m hurdles showed substantial improvements of 0.3–0.7%. Some middle- and long-distance events (800–10,000 m) showed marginal impairments at altitudes above 150 m, but above 1000 m the impairments increased dramatically to ~2–4% for events >800 m. There was no consistent trend in the effects of altitude on field events up to 1000 m; above 1000 m, hammer throw showed a marginal improvement of ~1% and discus was impaired by 1–2%. Above 1500 m, triple jump and long jump showed marginal improvements of ~1%.Conclusions:In middle- and long-distance runners, altitudes as low as 150 to 299 m can impair performance. Higher altitudes (≥1000 m) are generally required before decreases in discus performance or enhancements in sprinting, triple and long jump, or hammer throw are seen.

2019 ◽  
Vol 56 (1) ◽  
pp. 45-57
Author(s):  
Iwona Mejza ◽  
Katarzyna Ambroży-Deręgowska ◽  
Jan Bocianowski ◽  
Józef Błażewicz ◽  
Marek Liszewski ◽  
...  

SummaryThe main purpose of this study was the model fitting of data deriving from a three-year experiment with barley malt. Two linear models were considered: a fixed linear model with fixed effects of years and other factors, and a mixed linear model with random effects of years and fixed effects of other factors. Two cultivars of brewing barley, Sebastian and Mauritia, six methods of nitrogen fertilization and four germination times were analyzed. Three quantitative traits were observed: practical extractivity of the malt, malting productivity, and a quality coefficient Q. The starting point for the statistical analyses was the available experimental material, which consisted of barley grain samples destined for malting. The analyses were performed over a series of years with respect to fixed or random effects of years. Due to the strong differentiation of the years of the study and some significant interactions of factors with years, annual analyses were also carried out.


1994 ◽  
Vol 24 (3) ◽  
pp. 568-575 ◽  
Author(s):  
D.A.J. Ryan ◽  
O.B. Allen ◽  
D.L. McLaughlin ◽  
A.M. Gordon

This study presents a new method for assessing the impact of environmental factors on the radial growth rate of trees. The natural logarithm of the specific volume increments (SVI) were fitted to a mixed linear model, which included fixed effects for tree age when the increment occurs, year, precipitation, and temperature both in the year of growth and in the preceding year, and the geographical locale. The model also incorporates stand and tree as random effects. By fitting trees of different ages, the model is able to separate year effects from age effects. Age and year were treated as categorical variables and hence no specific form of growth curve is assumed. The model was fitted to log SVI from 84 mature sugar maple (Acersaccharum Marsh.) trees from 42 uneven-aged stands in six regions of southern and central Ontario representing a known gradient of air pollution. After adjusting for age, precipitation, and temperature effects, the log SVI increased during the first half and declined during the second half of the 20th century in five of the six regions. This suggests that factors other than those included in the model have affected growth. Air pollution remains a likely causal agent in this observed decline.


1991 ◽  
Vol 74 (9) ◽  
pp. 3174-3182 ◽  
Author(s):  
K.A. Weigel ◽  
D. Gianola ◽  
R.J. Tempelman ◽  
C.A. Matos ◽  
I.H.C. Chen ◽  
...  

2020 ◽  
Vol 50 (4) ◽  
pp. 339-345
Author(s):  
Erika SOUZA ◽  
Ana COELHO ◽  
Alfredo P. SANTOS-JR ◽  
Ricardo Alexandre KAWASHITA-RIBEIRO ◽  
Rafael de FRAGA

ABSTRACT In ectotherms, defensive responses to predators usually depend on cost-benefit relationships between death risk and the energy required to flee. In this study we investigate Amazonian lizards to test the hypothesis that the minimum predator approach distance (PAD) is influenced by temperature and camouflage. We test the hypothesis that PAD estimated for species with different thermoregulation modes respond differently to temperature and camouflage. We sampled 35 lizards of a heliotherm and a non-heliotherm species, for which we simulated a terrestrial visually oriented predator. Using a fixed-effects linear model, temperature positively affected PAD estimates, but the camouflage did not contribute to the model. Using a mixed linear model assuming thermoregulation mode as a random factor, camouflage negatively affected PAD estimates, independently of temperature. Our findings suggest that high exposure to predators in open habitats may be compensated by rapid fleeing optimized by high temperatures, and low fleeing performance, usually caused by relatively low temperatures in shaded habitats, may be compensated by camouflage. However, identifying the best PAD predictor greatly depended on accounting for thermoregulation mode in hypothesis testing, although the results obtained by both fixed and mixed-effects models may be relevant for conservation.


1999 ◽  
Vol 9 (2) ◽  
pp. 202-212 ◽  
Author(s):  
Katsumi Sugiura ◽  
Izumi Suzuki ◽  
Kando Kobayashi

Mean daily intakes of energy and nutrients were surveyed from 3-day food records for 62 elite Japanese track-and-field athletes (28 males and 34 females) selected to participate in the 1994 Asian Championship games held in Hiroshima, Japan. Mean energy intakes of male and female athletes were 3,141 kcal (±592) and 2,508 kcal (±537), respectively. Based on the Japanese Recommended Dietary Allowances (JRDAs), long-distance and middle-distance runners had significantly higher energy and macronutrient intakes than did sprinters, jumpers, and throwers. There was no significant difference in micronutrient intake among the different types of athletes. However, of the sprinters, jumpers, and throwers. 15 males (54%) and 22 females (65%) consumed less than the JRDA for at least one micronutrient (i.e., vitamin or mineral). For some athletes, nutritional counseling that provides strategies for increasing food intake is recommended to optimize nutrient intake.


2020 ◽  
Vol 15 (9) ◽  
pp. 1231-1236 ◽  
Author(s):  
Sergei Iljukov ◽  
Jukka-Pekka Kauppi ◽  
Arja L.T. Uusitalo ◽  
Juha E. Peltonen ◽  
Yorck O. Schumacher

The purpose of this research was to evaluate the performances of female middle- and long-distance runners before and after the implementation of a new antidoping strategy (the Athlete Biological Passport [ABP]) in a country accused of systematic doping. A retrospective analysis of the results of Russian National Championships from 2008 to 2017 was performed. The 8 best female performances for the 800-m, 1500-m, 3000-m steeplechase, 5000-m, and 10,000-m events from the semifinals and finals were analyzed. The yearly number of athletes fulfilling standard qualifications for international competitions was also evaluated. Overall, numbers of athletes banned for doping in 2008–2017 were calculated. As a result, 4 events (800, 1500, 5000 [all P < .001], and 10,000 m [P < .01]) out of 5 showed statistically significant deterioration in the performances when comparing before and after the introduction of the ABP. The 3000-m steeplechase was the only event that did not show statistically significant change. The highest relative decrease in the number of runners who met standard qualification for international competition was for the 5000-m event (46%), followed by 1500-m (42%), 800-m (38%), 10,000-m (17%), and 3000-m steeplechase (1%). In conclusion, implementation of the ABP was followed by a significant reduction in the performance of female runners in a country accused of systematic doping. It can be reasonably speculated that more stringent antidoping testing, more specifically the introduction of the ABP, is a key reason for this reduction.


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