Athletes, Sports
Conditions
Keywords
rice germ, swimmers, nutritional supplement, lactic acid, fat free mass
Brief summary
In order to enhance the effects of training and improve performance, athletes often turn to nutritional supplements. According to the American College of Sports Medicine (ACSM), adequate selection of nutrients and supplements, adjusting intake according to the exercise performed, is necessary for optimal performance in athletes. The most recent consensus from the International Society for Sport Nutrition (ISSN), The American Dietetic Association (ADA) and ACSM on sport nutrition have been reviewed by Potgieter, stating that a single guideline is not sufficient to elaborate an individualized and focused nutritional management of athletes. Moreover, apart from the abovementioned guidelines, sport-specific nutritional strategies, including quantity, structure and timing of food (or supplement) intake should also be followed in order to maximize sports performance and recovery. The importance of dietary supplementation is of particular interest in swimming, where athletes usually undertake a training approach characterized by a high volume of training during aerobic development and high intensity training during the competition phase, coupled with strength training. The size and market value of the sports supplement industry is continuing to grow, with health, safety and contamination concerns becoming more pressing. Therefore, it is important to identify dietary supplements that are safe and effective in supporting swimmers. Rice germ could be a safe and effective dietary supplement for swimmers. In the last few years, scientific research is trying to use waste rice products in the pharmaceutical and nutraceutical fields, considering the potential value of nutrients they contain. In particular, rice germ has a high protein and essential amino acids, such as lysine, histidine and valine content, a good lipid content (with prevalence of mono- unsaturated and polyunsaturated fatty acids - in particular linoleic and linolenic essential fatty acids and oleic acid), an high fiber presence; regarding water-soluble vitamins, rice germ has high content if thiamine (B1) and pyridoxine (B6), while vitamin E prevails for liposoluble vitamins. About minerals, are most present iron and magnesium. All these nutrients play important roles in maintaining the health of athletes. Currently, despite these characteristics, no study has evaluated the potential beneficial effect of RG supplementation on athletes. Given this background, the purpose of this investigation was to ascertain whether performance in swimmers could be improved by a 5-weeks of RG supplementation.
Interventions
DIETARY_SUPPLEMENTRice germ
25 g twice a day.
DIETARY_SUPPLEMENTWheat-based supplement
25g twice a day.
Sponsors
Azienda di Servizi alla Persona di Pavia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
SUPPORTIVE_CARE
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
ALL
Healthy volunteers
Yes
Inclusion criteria
* moderately trained athletes * regularly involved in regional and national competitions
Exclusion criteria
* No history of cardiac or respiratory disease * no medication at the time of the study * no abnormalities on physical examination or on resting electrocardiogram
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Performance change | At baseline and after 5 weeks of supplementation | Whether the performance in 50m, 200m, is improved in a 25m swimming pool in front crawl at maximal speed. Performance measured in seconds. |
| Lactic acid production change | At baseline and after 5 weeks | Capillary blood samples were collected from the fingertip before and after each swimming (at the 1st and 3rdmin of recovery) to access the higher values of blood lactate concentration (AccutrendLactate®Roche, Germany). |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Antropometric measures change (circumferences) | At baseline and after 5 weeks of supplementation | Waist circumference (cm), hip circumference (cm), mid-arm circumference (cm). |
| Change in Total fat mass, total free fat mass and visceral adipose tissue (DXA) | At baseline and after 5-weeks of supplementation | Body composition by dual-energy X-ray absorptiometry (DXA). Body composition was measured at baseline by DXA, using a Lunar Prodigy DEXA (GE Medical Systems, Waukesha, WI). Free Fat mass, Fat mass and visceral fat (kg) data were derived from DXA using the DXA Prodigy enCORE software (version 17; GE Healthcare). |
| Body composition parameters change (BIVA) | At baseline and after 5-weeks of supplementation | Body composition analyzed with BIVA: free fat mass, fat mass, body cellular mass change (kg). |
| Antropometric measures change (skinfolds) | At baseline and after 5 weeks of supplementation | skinfolds thicknesses (mm) (biceps, triceps, suprailiac, subscapular), measured twice using a Harpenden skinfold caliper at 5 min intervals at each site |
| Registration of adverse effects | After 7 days, 14 days, 21 days, 28 days from baseline and after 5 weeks. | Adverse effects recorded, through phone call |
| Muscle function change | At baseine and after 5 weeks. | The JAMAR Hand Dynamometer (Jamar 5030J1; Sammons Preston Rolyan; accuracy 0.6 N) was used to assess muscle function with the use of a standardized procedure(Spijkerman, Dorine C., Snijders, Chris J., Stijnen, Theo, & Lankhorst 1991). Handgrip measured in kilograms. |
| Hydration parameters change (BIVA) | At baseline and after 5-weeks of supplementation | Hydration analyzed with BIVA: total body water, extracellular water, intracellular water change (L) |
| Body weight change (kg) | At baseline and after 5 weeks of supplementation | Change in body weight (kg). |
Outcome results
None listed