[Show abstract][Hide abstract] ABSTRACT: Explanations for the phenomenal success of East African distance runners include unique dietary practices. The aim of the present study was to assess the food and macronutrient intake of elite Ethiopian distance runners during a period of high intensity exercise training at altitude and prior to major competition.
The dietary intake of 10 highly-trained Ethiopian long distance runners, living and training at high altitude (approximately 2400 m above sea level) was assessed during a 7 day period of intense training prior to competition using the standard weighed intake method. Training was also assessed using an activity/training diary.
Body mass was stable (i.e., was well maintained) over the assessment period (pre: 56.7 ± 4.3 kg vs. post: 56.6 ± 4.2 kg, P = 0.54; mean ± SD). The diet comprised of 13375 ± 1378 kJ and was high in carbohydrate (64.3 ± 2.6%, 545 ± 49 g, 9.7 ± 0.9 g/kg). Fat and protein intake was 23.3 ± 2.1% (83 ± 14 g) and 12.4 ± 0.6% (99 ± 13 g, 1.8 ± 0.2 g/kg), respectively. Fluid intake comprised mainly of water (1751 ± 583 mL), while no fluids were consumed before or during training with only modest amounts being consumed following training.
Similar to previous studies in elite Kenyan distance runners, the diet of these elite Ethiopian distance runners met most recommendations of endurance athletes for macronutrient intake but not for fluid intake.
Journal of the International Society of Sports Nutrition 01/2011; 8:7. · 1.83 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To determine the frequency of the ACTN3 R577X polymorphism (functional R allele and nonfunctional X allele) in a variety of African populations and to examine its influence on the success of elite East African endurance runners and West African sprinters.
The R577X polymorphism was genotyped in 198 Ethiopian controls and 76 elite Ethiopian endurance athletes, 158 Kenyan controls and 284 elite Kenyan endurance runners, and 60 Nigerian controls and 62 elite Nigerian power athletes. Statistical analyses were performed by exact tests of population differentiation, using Arlequin, version 3. Analyses were carried out using 1 x 10(6) Markov chain steps, and 1 x 10(5) dememorization steps.
The frequency of the X allele was extremely low among Kenyans and Nigerians (approximately 1% homozygosity) and higher in Ethiopians (approximately 11% homozygosity). The low baseline frequencies of the three populations tested mean that any associations with sprint performance would likely be obscured. In Ethiopians, where baseline levels of 577XX were about 11%, there was no increased frequency in the endurance athletes.
Our data suggest that alpha-actinin-3 deficiency is not a major influence on performance in African athletes.
Medicine & Science in Sports & Exercise 12/2007; 39(11):1985-8. · 4.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Previous studies have hypothesised that mitochondrial DNA (mtDNA) polymorphisms may influence aerobic performance. The matrilineal inheritance and accumulation of polymorphisms in mtDNA means that mtDNA haplogroups, characterised by key polymorphisms, are often represented at different frequencies in different populations. The present study aimed to compare the mtDNA haplogroup distribution of elite Ethiopian athletes relative to the general Ethiopian population. The haplogroup distribution of 76 endurance athletes (E), members of the Ethiopian national athletics team, was compared to 108 members of the general Ethiopian population (C). DNA was extracted from buccal swabs and haplogroups assigned by sequencing part of the hypervariable sequence (HVS-I), followed by analysis of key coding-region polymorphisms. A high proportion of African 'L' haplogroups was found in athletes and controls (C=53%; E=55%). Haplogroup distribution of endurance runners did not differ from that of C (P=0.63). Elite Ethiopian athletes are not a mitochondrially distinct group relative to the Ethiopian population. It appears that environment and, perhaps, polymorphisms in the nuclear genome are more important determinants of Ethiopian running success than mtDNA polymorphisms.
Comparative Biochemistry and Physiology Part B Biochemistry and Molecular Biology 04/2005; 140(3):497-503. · 2.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Favourable genetic endowment has been proposed as part of the explanation for the success of East African endurance athletes, but no evidence has yet been presented. The Y chromosome haplogroup distribution of elite Ethiopian athletes (n=62) was compared with that of the general Ethiopian population (n=95) and a control group from Arsi (a region producing a disproportionate number of athletes; n=85). Athletes belonged to three groups: marathon runners (M; n=23), 5-km to 10-km runners (5-10K; n=21) and other track and field athletes (TF; n=18). DNA was extracted from buccal swabs and haplogroups were assigned after the typing of binary markers in multiplexed minisequencing reactions. Frequency differences between groups were assessed by using contingency exact tests and showed that Y chromosome haplogroups are not distributed amongst elite Ethiopian endurance runners in the same proportions as in the general population, with statistically significant (P<0.05) differences being found in four of the individual haplogroups. The geographical origins and languages of the athletes and controls suggest that these differences are less likely to be a reflection of population structure and that Y chromosome haplogroups may play a significant role in determining Ethiopian endurance running success.
Human Genetics 12/2004; 115(6):492-7. · 4.63 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: The dominance of East-African athletes in distance running remains largely unexplained; proposed reasons include favorable genetic endowment and optimal environmental conditions.
To compare the demographics of elite Ethiopian athletes with the general Ethiopian population and assess the validity of reports linking running long distances to school with endurance success.
Questionnaires, administered to 114 members (male and female) of the Ethiopian national athletics team and 111 Ethiopian control subjects (C) obtained information on place of birth, language, distance and method of travel to school. Athletes were separated into three groups according to athletic discipline: marathon (M; N = 34); 5,000-10,000 m (5-10 km; N = 42); and other track and field athletes (TF; N = 38). Frequency differences between groups were assessed using contingency chi-square tests.
Regional distributions of marathon athletes differed from controls (P < 0.001) and track and field athletes (P = 0.013), but not the 5- to 10-km athletes (P = 0.21). The 5- to 10-km athletes also differed from controls (P < 0.001). Marathon athletes exhibited excess from the regions of Arsi and Shewa (M: 73%; 5-10 km: 43%; TF: 29%; C: 15%). The language distribution of marathon athletes differed from all groups (P < 0.001), with a predominance of languages of Cushitic origin (M: 75%, 5-10 km: 52%, TF: 46%, C: 30%). A higher proportion of marathon athletes ran to school (M: 68%; 5-10 km: 31%; TF: 16%; C: 24%) and traveled greater distances.
Elite endurance athletes are of a distinct environmental background in terms of geographical distribution, ethnicity, and also having generally traveled farther to school, often by running. These findings may reflect both environmental and genetic influences on athletic success in Ethiopian endurance athletes.
Medicine & Science in Sports & Exercise 10/2003; 35(10):1727-32. · 4.48 Impact Factor