Van woensdag 5 tot en met zaterdag 8 juli vond in Essen (Duitsland) het 22e congres van het European College of Sport Science (ECSS) plaats.

“The European College of Sport Science is an international non-profit organization founded in Nice, France in 1995. Its purpose is the promotion of science and research, with special attention to the interdisciplinary fields of sport science and sports medicine.”

SEN collega’s Naomi Brinkmans, Cindy van der Avoort, Kristin Jonvik, Floris Wardenaar, Jan Willem van Dijk en een aantal studenten waren hierbij aanwezig. Tijdens dit internationale congress presenteren onderzoekers hun recentelijke werk op het gebied van sport en presatatie, met meer dan 1700 presentaties en posters! Ook Naomi, Kristin en Floris presenteerden hier hun onderzoeken, waarmee Kristin een knappe 5e plek behaalde in de speciale sport en voeding sessie, georganiseerd door de Gatorade Sports Science Institute (GSSI). Bekijk de abstract van Floris onderstaand.

Een leerzame en vooral inspirerende week.

Abstract Naomi Brinkmans

ENERGY EXPENDITURE AND FOOD INTAKE OF PROFESSIONAL FOOTBALL PLAYERS IN THE DUTCH PREMIER LEAGUE:

IMPLICATIONS FOR NUTRITIONAL COUNSELING

BRINKMANS, N.Y.J., IEDEMA, N., PLASQUI, G., SARIS, W.H.M., VAN LOON, L.J.C., VAN DIJK, J.W.

HAN UNIVERSITY OF APPLIED SCIENCES, MAASTRICHT UNIVERSITY MEDICAL CENTRE

Introduction

Selecting appropriate dietary strategies and optimizing the diet for professional football players requires detailed information on their

energy expenditure and dietary intake. So far, information on energy requirements and dietary intake of football players is limited to small

cohorts or amateurs. The aim of this study was to determine the energy expenditure and dietary intake in a representative sample of

professional football players.

Methods

A total of 41 professional football players (age 23±4 y, height 1.82±0.06 m, bodyweight 77.6±8.0 kg) from three football teams playing in

the Dutch premier league (Eredivisie) participated in this observational study. Energy expenditure (EE) was determined over a 14-day

period by the doubly labeled water method (DLW). Dietary intake was assessed by three face-to-face 24h recalls, including a match,

training, and rest day. Dietary intake was processed by Compl-eat™ software, and analyzed for energy and macronutrient intake. Comparisons

between match, training, and rest days were made by repeated measures ANOVA. Data are reported as means±SD.

Results

The 14-day period contained 2.3±0.5 match, 8.7±1.0 training and 3.1±1.0 rest days. The mean daily EE assessed over the 14-day period

was 13.7±1.5 MJ/day (178±41 kJ/kg bodyweight), and correlated well with bodyweight (r=0.68; p<0.001). The weighed mean energy

intake (EI) was 11.1±2.9 MJ/day, indicating 18±15% underreporting of EI. The daily EI was higher on match days (13.1±4.1 MJ) compared

with training (11.1±3.4 MJ; p<0.01) and rest days (10.5±3.1 MJ; p<0.001). In agreement, daily carbohydrate intake was significantly higher

during match days (5.1±1.7 g/kg bodyweight) compared with training (3.9±1.5 g/kg bodyweight; P<0.001) and rest days (3.7±1.4 g/kg

bodyweight; p<0.001). The daily protein intake on match, training, and rest days was 1.8±0.6, 1.7±0.6 and 1.5±0.5 g/kg bodyweight,

respectively. The distribution of protein intake over the day was quite skewed, with the lowest intakes reported at breakfast and highest

intakes at dinner.

Discussion

The daily energy requirements of professional football players are modest, with an average daily energy requirement of ~13.8 MJ (178

kJ/kg bodyweight). The daily intake of carbohydrates is below the general recommendations for football players and should be increased

to maximize performance and recovery. Daily protein intake seems to be adequate according to the recommendations, but should be

distributed more evenly throughout the day.

Abstract Floris Wardenaar

SELF-REPORTED CARBOHYDRATE DURING EXERCISE ASSESSED BY A STANDARDIZED QUESTIONNAIRE IS HIGHER

THAN THE OBSERVED CARBOHYDRATE INTAKE.

WARDENAAR, F.C.1, VAN DER BURG, N.1, VAN DIJK, J.W.1, VAN LOON, L.J.C.2, DE VRIES, J.H.M.3

1. HAN UNIVERSITY OF APPLIED SCIENCES; 2. MAASTRICHT UNIVERSITY; 3. WAGENINGEN UNIVERSITY

Introduction

To optimize carbohydrate (CHO) intake during exercise, accurate individual dietary assessment is needed. Given the lack of biomarkers

for absolute CHO intake, questionnaires are generally used to gain insight in the food intake of athletes during sport events. We compared

CHO intake during a cross-duathlon in recreative athletes assessed by a standardized post-exercise food frequency questionnaire

with standardized food items (FFEQ) against well-controlled observations of food intake.

Methods

Food intake of 31 trained athletes (24 men and 7 women) during a cross-duathlon (7.0 km running, 20.0 km mountainbiking and 3.5 km

running) was assessed by a previously used questionnaire (FFEQ) along with real-time observations. As part of the observation, the

athletes’ foods and drinks were labeled and weighed, and photographs were taken from all available ingredient declarations. During the

race, empty bottles and food wraps were dropped by the athletes, and collected and weighed by the research team. Subsequently,

products were weighed to determine the consumed amount. After the race, athletes reported the foods ingested during the race by filling

out the FFEQ consisting of 15 frequently used food items during exercise. Mean CHO intake (g.h-1±SD) was calculated using a food composition

table (NEVO) or ingredient declarations, and the difference in CHO intake between both methods was analyzed using Wilcoxonsigned-

rank-test with statistical significance set at p<0.05. The relationship between methods was investigated using Spearman’s correlation

coefficient with 95% CI. The level of agreement between methods on individual level was assessed by Bland-Altman analysis.

Results

The race was completed in 127±27 minutes. Mainly (isotonic) sports drinks and gels were used during the race. Mean CHO intake assessed

by the FFEQ (34.3±27.5 g.h-1) was 9.8±16.9 g.h-1 higher than the observed CHO intake (24.5±19.6 g.h-1; p=0.004). There was a

good correlation between both methods (r=.79; 95% CI: 0.61-0.89). The Bland-Altmanplot, presenting the average CHO intakes of the two

methods against the difference of the two methods, showed 95% limits of agreement of -26.5 and 47.2 g.h-1.

Conclusion

Self-reported CHO intake during exercise as determined by a standardized post-exercise food frequency questionnaire can be substantially

higher than the amount of carbohydrates that is actually consumed. This finding suggests that self-reported food intake during

exercise should be interpreted with caution.