Glide efficiency, the ability of a body to minimize deceleration over the glide, can change with variations in the body’s size and shape. The purpose of this study was to investigate the relationships between glide efficiency and the size and shape characteristics of swimmers. Eight male and eight female swimmers performed a series of horizontal glides at a depth of 70 cm below the surface. Glide efficiency parameters were calculated for velocities ranging from 1.4 to 1.6 m/s for female swimmers (and at the Reynolds number of 3.5 million) and from 1.6 to 1.8 m/s for male swimmers (and at the Reynolds number of 4.5 million). Several morphological indices were calculated to account for the shape characteristics, with the use of a photogrammetric method. Relationships between the variables of interest were explored with correlations, while repeated-measures ANOVA was used to assess within-group differences between different velocities for each gender group. Glide efficiency of swimmers increased when velocity decreased. Some morphological indices and postural angles showed a significant correlation with glide efficiency. The glide coefficient was significantly correlated to the chest to waist taper index for both gender groups. For the male group, the glide coefficient correlated significantly to the fineness ratio of upper body, the chest to hip cross-section. For the female group the glide coefficient had a significant correlation with the waist to hip taper index. The findings suggested that gliding efficiency was more dependent on shape characteristics and appropriate postural angles rather than being dependent on size characteristics.
Roozbeh Naemi, Stelios G. Psycharakis, Carla McCabe, Chris Connaboy and Ross H. Sanders
Jadwiga Malczewska, Beata Szczepańska, Romuald Stupnicki and Witold Sendecki
The transferrin receptor-ferritin index (sTfR/logFerr) was determined in 131 male and 121 female athletes in order to assess the frequency of iron deficiency (threshold value of that index taken as 1.8). Blood was drawn for determining morphological indices as well as sTfR, ferritin, iron, total iron binding capacity (TIBC), and haptoglobin. A significantly (p < .01) higher incidence of iron deficiency was observed in women (26%) than in men (11%). The iron deficiency was latent, since no subject was found to be anemic. The plasma iron was significantly lower and TIBC higher (p < .001) in both iron-deficient subgroups than in the non-deficient ones. This confirmed the latent character of iron deficiency. Some hematological indices (Hb, MCH, MCHC, MCV) were significantly lower in iron-deficient female athletes than in male athletes, which suggested a more profound iron deficiency in the former. The sTfR/logFerr index might thus be useful in detecting iron deficiency in athletes, especially in those with erythropoiesis disorders, since physical loads may affect the widely used ferritin levels.
Alan J. McCubbin, Bethanie A. Allanson, Joanne N. Caldwell Odgers, Michelle M. Cort, Ricardo J.S. Costa, Gregory R. Cox, Siobhan T. Crawshay, Ben Desbrow, Eliza G. Freney, Stephanie K. Gaskell, David Hughes, Chris Irwin, Ollie Jay, Benita J. Lalor, Megan L.R. Ross, Gregory Shaw, Julien D. Périard and Louise M. Burke
.11.2.223 Malczewska-Lenczowska , J. , Sitkowski , D. , Orysiak , J. , Pokrywka , A. , & Szygula , Z. ( 2013 ). Total haemoglobin mass, blood volume and morphological indices among athletes from different sport disciplines . Archives of Medical Science, 9 ( 5 ), 780 – 787 . PubMed ID: 24273557 doi:10