BIVA and anthropometric assessment of youth water polo players

Published: 24 May 2024| Version 1 | DOI: 10.17632/8677by7j68.1
Sofia Serafini,


Twenty-four young water polo players (age: 13.30yrs ± 0.55), took part in the study. To be included, participants needed to have consistently trained over the past year and competed in the regional championship. Exclusion criteria included having no injuries or clinical conditions at the time of the study, not being on medication, and not following any special dietary plans (e.g., hypo- or hyper-caloric diets). Data were collected before and after a typical training session aiming to i) characterize young water polo players in terms of anthropometric and bioelectrical profile and according to the maturity offset and ii) provide information on hydration changes after training, using the bioelectrical impedance vector analysis. Dataset includes demographic details (such as years of practice, weekly training frequency and duration, and other sports previously or currently practiced), anthropometry (including basal measurements such as stature, body mass, and sitting height, girths, and skinfolds), bioelectrical values (such as raw resistance and reactance), and derived body composition (body mass index, waist to height ratio, fat mass) and maturity offset (peak height velocity, adult stature) values.


Steps to reproduce

A few days prior to the initial assessment, demographic details were gathered via a questionnaire. Participants were instructed to avoid caffeine, alcohol, and exercise the day before the bioelectrical impedance analysis (BIA. They were also advised to drink 3.0 liters of fluid within 24 hours (with 2.0 liters consumed between 6:00 p.m. and 10:00 p.m.) alongside their usual diet. No food or drink was permitted from 10:00 p.m. until the assessment the following morning. From 8:00 a.m. to 10:00 a.m., after monitoring their skin temperature, the players underwent anthropometric and BIA measurements after voiding, dressed in light clothing without metal components. Participants had a standardized breakfast consisting of a cheese and ham sandwich, a banana, and 400 mL of fruit juice. At 11:00 a.m., they engaged in a specific training session. Water intake was monitored and recorded throughout. After training, the athletes did not consume any fluids for at least one hour until the completion of further tests. One-hour post-training, after controlling skin temperatures, BIA and anthropometric measurements were repeated. Perceived exertion was measured using the Modified Borg RPE Scale after the training session. Basal measures were taken using a stadiometer with a balance (Seca 200, Seca, Hamburg, Germany). Circumferences were measured with a Cescorf anthropometric tape (Cescof, Porto Alegre, Brazil). Skinfold thickness was measured using a Holtain skinfold caliper (Holtain, Crosswell, UK). The percentage of fat mass (%FM) was determined using the Slaughter equation for pubertal boys. Maturity offset was estimated on the basis of the distance from peak height velocity (PHV) in years (YPHV), derived from stature, sitting height, age, and their interactions, according to Mirwald. Predicted adult height (PAH) and the percentage of PAH (%PAH) were estimated using the Sherar method. Bioimpedance analysis was conducted using a BIA 101 Anniversary AKERN device (Florence, Italy) with a 50 kHz (±1%) electric current. The device was calibrated before each use with a standard control circuit (resistance = 380 ohms; reactance = 45 ohms). Participants lay supine for a minimum of two minutes, with legs spread at a 45° angle and arms at a 30° angle from the trunk. Disposable electrodes with very low intrinsic impedance (<30 ohms) (BiatrodesTM Akern Srl; Florence, Italy) were placed on the right wrist and ankle. The assessment was performed on an isolated cot. Bioimpedance vector analysis was done using the BIVA method, normalizing R and Xc values by stature. The phase angle (PhA) was calculated as the arctangent of Xc/R×(180◦/π). Skin temperature was measured at the temple using a non-contact digital infrared thermometer (Mini Flash, TFA Dostmann GmbH & Co, Wertheim, Germany). Post-training exams were performed once temperatures were similar to pre-training values.


Sport, Anthropometry, Youth, Electrical Impedance, Sport Training, Anthropometric Assessment, Hydration