Body dimensions, exercise capacity and physical activity level of adolescent Nandi boys in western Kenya

Abstract

The aim of this study was to characterize untrained Nandi boys (mean age 16.6 years) from a town (n = 11) and from a rural area (n = 19) in western Kenya (altitude approximately 2000 m.a.s.l.) in regard to their body dimensions, oxygen uptake and physical activity level. The town boys had a mean maximal oxygen uptake (VO(2 max)) of 50 (range: 45-60) mL kg(-1) min(-1), whereas the village boys reached a value of 55 (37-63) mL kg(-1) min(-1) ( p<0.01) in VO(2 max). The running economy, determined as the oxygen cost at a given running speed, was 221 mL kg(-1) km(-1) (597 mL kg(-0.75) km(-1)) for town as well as for village boys. The body mass index (BMI) was very low for town as well as for village boys (18.6 vs 18.4 kg m(-2)). The daily mean time spent working in the field during secondary school and doing sports were significantly higher in village boys compared to town boys (working in the field: 44.2 (0-128) vs 1.3 (0-11) min, p<0.01; sports: 32.0 (11-72) vs 12.8 (0-35) min, p<0.01, respectively). A positive correlation between the daily time spent doing sports and VO(2 max) was found when pooling the data from the town and the village boys (R = 0.55, p<0.01). It is concluded that the body dimensions of adolescent Nandi town and village boys corresponds well with findings in Kenyan elite runners. They are very slender with relatively long legs. In addition, the VO(2 max) of the village boys was higher than that of the town boys, which is probably due to a higher physical activity level of the village boys during secondary school.

Running biomechanics: shorter heels, better economy

“…As in previous studies, a relationship was found M. N. Scholz and others between running economy and foot length (Anderson, 1996) and between running economy and BMI or lower-leg volume/moment of inertia (Anderson, 1996;Larsen et al, 2004). However, we showed that these relationships were no longer significant after correcting each variable (i.e.…”

Cardio-respiratory fitness markers among Kenyan university students using a 20m shuttle run test (SRT)

“…Previous studies 24,25 demonstrated a similar pattern of lower VO 2max among the more sedentary individuals. It appears that it is only with regular exercise regimes that university-attending individuals may attain a minimum-for-age VO 2max , as has previously been suggested 18 . It also appears that VO 2max is a more complete indicator of the fitness differences among subjects given that HR was affected by individuals dropping from the SRT at different levels, and the BP measures did not yield strict statistical differences.…”

“…Similarly aged male who exercised regularly attained VO 2max of 62 (58-71) ml/kg/min whereas runners in active training had VO 2max values of up to 68±1.4 ml/kg/min. 17 Another study comparing town and village dwellers 18 showed males of mean age 16.6 years from town setting attaining a mean VO 2max of 50 (45-60) ml/ kg/min whereas their village counterparts attained 55 (37-63) ml/kg/min (p<0.01).…”

Rendimiento excelente en las carreras de larga distancia : estudio comparado de corredores kenianos y españoles de alto rendimiento = Excellent performance in long distance races : high performance kenyan and spanish runners comparative research

“…Sin embargo, un estudio de Favier, Spielvogel, Desplanches, Ferretti, Kayser y Hoppeler (1995) reveló que no mejoraban mucho su VO₂ máx cuando se les estudiaba a nivel del mar. Aunque pueda haber una pequeña diferencia se debe considerar que la masa corporal de los chicos Nandi era solo 54 kg de media (Larsen et al, 2004), que es 12 kg de media menos que los chicos de origen caucásico (Andersen, 1994). Si el VO₂ máx es normalizado con el exponente 0,75, los chicos kenianos tendrán un VO₂ máx menor que el de los chicos de origen caucásico.…”

“…Por ello, los corredores kenianos de larga distancia de élite son más delgados que los corredores de élite escandinavos (Saltin et al, 1995b). Además, un estudio de chicos kenianos desentrenados demostró que no solo tenían una masa corporal más baja, sino que su masa corporal era mucho menor que la de la mayoría de los chicos de su edad de otros continentes (Larsen et al, 2004). Este estudió también indicó que la circunferencia de la pantorrilla de los chicos kenianos era menor que la de los chicos escandinavos.…”