Case studies: Effects of beef, whey and carbohydrate supplementation in female master triathletes

Appropriate nutritional supplementation is crucial for athletic performance, particularly for female endurance athletes as their numbers steadily increase. This report involves a set of six case studies examining the effects of ingesting a post-workout supplement containing beef, or whey or carbohydrate on iron status, blood indices, muscular thickness, peak oxygen consumption (VO2 max) and body composition in six female masters-age (> 35 years old) triathletes. Over a 10-week training period, a 20 g supplement was ingested immediately post workout or during breakfast on the non-training days. Of the six analyzed cases, two ingested protein powder from beef, two consumed whey, and two consumed maltodextrin. Data showed that concomitant with increased dietary iron ingestion, levels of the iron-storage protein ferritin increased in beef-consumers (by 56% and 74 %) and carbohydrate-consumers (by 71% and 27 %), but decreased in whey-consumers (by 55% and 36%). Contrastingly, the effect on transferrin levels was highly variable between participants in each supplementation case. The whey-consumers showed reduced RBC count (by 6%), hematocrit (by 8%) and red blood cell distribution width (by 14% and 5%). While one beef-consumer showed a remarkable 34% increase in platelets, the whey and carbohydrate-consumers showed reduced platelets, but increased neutrophil:lymphocyte ratio. Vastus medialis thickness reduced in carbohydrate-consumers (by 6% and 5%), unlike the beef and whey-consumers. Females consuming beef increased iron stores and platelets, while those ingesting whey were unable to maintain specific RBC indices. Only the four athletes ingesting protein-containing supplements were able to maintain muscle thickness, thereby averting muscle loss

Validity and reliability of a novel optoelectronic device to measure movement velocity, force and power during the back squat exercise

This study analysed the validity and reliability of a new optoelectronic device (Velowin) for the measurement of vertical displacement and velocity as well as to estimate force and mechanical power. Eleven trained males with Mean (SD) age = 27.4 (4.8) years, completed an incremental squat exercise test with 5 different loads (<30 – 90% of their 1−repetition maximum) while displacement and vertical velocity of the barbell were simultaneously measured using an integrated 3D system (3D motion capture system + force platform) and Velowin. Substantial to almost perfect correlation (concordance correlation coefficient = 0.75 – 0.96), root mean square error as coefficient of variation ±90% confidence interval 10% and good to excellent intraclass correlation coefficient = 0.84 – 0.99 were determined for all the variables. Passing and Bablock regression methods revealed no differences for average velocity. However, significant but consistent bias were determined for average or peak force and power while systematic and not proportional bias was found for displacement. In conclusion, Velowin, holds some potential advantages over traditionally used accelerometer or linear transducers, represents a valid and reliable alternative to monitor vertical displacement and velocity as well as to estimate average force and mechanical power during the squat exercise

Comparación del rendimiento motor entre niños futbolistas y niños no deportistas en la etapa prepuberal: Un estudio piloto / Comparison of motor performance between children soccer players and sedentary children during the prepubescent phase: A pilot study

RESUMEN: El propósito del presente estudio fue comparar el rendimiento motor entre niños jugadores de fútbol con niños no deportistas. Se utilizó una muestra de 27 niños sanos, 15 futbolistas (F; n= 12 niños y 3 niñas; 8,1 ± 0,4 años) y 12 no futbolistas (NF; n = 12, 10 niñas y 2 niños; 8,0 ± 0,0 años) que realizaron 5 pruebas destinadas a valorar su rendimiento motor: Carrera de velocidad de 30m (V30), carrera en zig-zag 10 m (Z10), salto con una pierna (SL), lanzamiento del balón medicinal (1kg) (Lz) y equilibrio estático unipodal (EQ). Los niños de grupo F mostraron un rendimiento significativamente más alto (p0,05) en las pruebas predominantemente cíclicas (V30 y CD10) ni en EQ. Posiblemente, en el caso las acciones predominantemente cíclicas o de equilibrio, las actividades que realizan los niños de forma libre o en las clases de educación física, constituyan un estímulo similar al que reciben los niños futbolistas. No obstante, con respecto a las acciones acíclicas más complejas (SL y Lz), la participación en programas dirigidos permitiría a los niños alcanzar niveles de rendimiento superiores. ABSTRACT: The aim of this study was to compare motor performance among a group of children regular football practitioner with another of non regular’s sports practitioner’s counterparts. Twenty seven children, 15 regular soccer player (S); 12 males and 3 females; 8.1 ± 0.4 years old, and 12; 10 males and 2 females; 8.0 ± 0.0 years, not enrolled in any regular and supervised physical activity, except that of school physical education class, (NS); performed 5 test aimed to assess their motor skills abilities performance: 30 m speed (30m), change direction 10 m sprint (CD10m), right and left one leg jump (LJ), 1 kg medicine ball throw (MBT) and 1 leg static balance (SB). S group showed better significantly performance for one leg-left jump and medicine ball throw (p0.05) neither for SB. It is possible that the spontaneous games or physical education class represents a similar stimulus respect to soccer training for increasing performance in predominantly cyclic or balances activities such as speed, change direction running or one leg balance test. However for more complex acyclic task such a throwing and one leg jump additional supervised and well designed activities could be necessary

Effectiveness of different postactivation potentiation protocols with and without whole body vibration on jumping performance in college athletes

This study examined the acute effects of different parallel squat postactivation potentiation protocols with and without whole body vibration on jumping performance in college athletes. Fifteen men (20.3 ± 1.3 years, 179.50 ± 5.3 cm, 81.0 ± 10.8 kg) performed 3 repetitions of a countermovement jump (CMJ) and best drop jump after 3 conditions: (a) parallel squat with 80% 1 repetition maximum without vibration (NV-PS), (b) parallel squat with 80% 1 repetition maximum on a whole body vibration platform (WBV-PS) (1.963-mm amplitude and 40 Hz), and (c) control (C). Each condition was performed under both low-volume (LV) (1 set of 3 repetitions) and high-volume (HV) (3 sets of 3 repetitions) protocols that were followed by both 1- and 4-minute rest periods. Significant improvements were observed for the CMJ height (p = 0.005) after 4 minutes of recovery and the LV protocol (p = 0.015) regardless of the condition. Additionally, for the WBV-PS condition, a significantly lower drop jump height was observed after 1 minute (p = 0.0022) after both low (p = 0.022) and HV (0.010) protocols. In conclusion, 4 minutes of recovery was adequate for improving CMJ height after an LV protocol regardless of the condition and restoring drop jump height performance after WBV-PS regardless of the protocol in male college athletes