Table 2. Factor validity of the knowledge on sport nutrition questionnaire (F – factor structure; FV – factor variance; PT – proportion of the explained variance).
F1 F2 F3 F4 F5 F6
Proteins consist of amino acids. –.01 –.02 .00 –.40 .25 .02
Carbohydrates are types of sugars and table sugar is basically a type of carbohydrate. .15 –.03 .08 –.31 .05 .80
Amino acids are only useful in endurance sports like the marathon or triathlon. .18 .47 .51 .00 –.09 .52
Isotonic drinks should be avoided in an extremely hot environment (temperatures above 35 degrees Celsius). .75 .34 .04 .31 –.25 .06
The negative side-effects of excessive sweating are best prevented by drinking pure water. –.05 –.23 –.29 –.14 .75 .36
Between tennis sets a banana is a better choice than an apple. .30 .03 –.05 .43 .07 .73
After the competition day has finished, it is better to not eat for 4 hours afterwards. .15 –.05 .20 .24 –.14 .80
Dark yellow urine is a sign of proper hydration of the body. .69 .00 .21 –.32 .13 .54
A banana has a lower glycemic index if it is green, and not dark yellow with spots. .66 .21 .29 –.19 .13 .38
For the first meal after a match, chicken breast (white meat) and eggs are a better choice than pasta. .13 .22 –.18 .54 .58 –.34
White rice is a better “pre-match” meal than wholemeal pasta. .62 .01 –.03 –.24 .45 –.53
Fresh fruit and vegetables are the best source of high-quality proteins. .72 –.14 .08 .32 .14 .33
Egg yolks and poultry are a valuable source of vitamins B and C. .02 –.62 .26 .51 .06 .28
During competitions in warm climates black tea can serve as beneficial sport drink. –.02 .16 .91 .13 .06 .10
Dried fruit is an excellent source of carbohydrates. .23 –.05 .86 .02 –.05 .10
Carbohydrate-laden meals should be avoided before matches because they encourage urination and therefore dehydration. .12 .18 .26 –.12 .81 –.14
Protein supplementation asks for an increased intake of water. .12 .86 .20 –.03 .12 .05
During journeys in which the time zone changes. it is better to avoid vitamins and herbal supplements since they can cause nausea and insomnia. .01 –.23 .19 .68 .05 .24
FV 2.64 1.74 2.34 1.95 2.00 3.34
PT .15 .10 .13 .11 .11 .19