142x Filetype PDF File size 0.36 MB Source: nutriweb.org.my
Mal J Nutr 26(2): 215-228, 2020 Randomised clinical trial of rice germ supplementation on nutritional status and performance in trained swimmers: A pilot study 1,2 3 4 4 Mariangela Rondanelli , Simone Perna , Gabriella Peroni , Milena A. Faliva , 4 5 2* 4 Mara Nichetti , Giancarlo Iannello , Vittoria Infantino , Clara Gasparri , 4 6 Daniele Spadaccini & Davide Guido 1 2 IRCCS Mondino Foundation, Pavia; Department of Public Health, Experimental and Forensic Medicine, Unit of Human and Clinical Nutrition, University of Pavia, Pavia, 3 27100, Italy; Department of Biology, College of Science, University of Bahrain, 4 Sakhir Campus P.O. Box 32038 Kingdom of Bahrain; Endocrinology and Nutrition Unit, Azienda di Servizi alla Persona “Istituto Santa Margherita”, University of Pavia, 5 Pavia, 27100, Italy; General Management, Azienda di Servizi alla Persona ‘‘Istituto 6 Santa Margherita’’, Pavia, 27100 Italy; Neurology, Public Health and Disability Unit, Scientific Directorate, IRCCS Foundation Neurological Institute Carlo Besta, Milan, 20133, Italy ABSTRACT Introduction: Rice germ (RG) could be a safe and effective dietary supplement for swimmers. Methods: This randomised, parallel, placebo controlled pilot study investigated the effect of a five-week RG supplementation (25 grams/two times/day) in moderately trained swimmers on 50-m and 200-m front crawl at maximal speed, as primary outcome, and body composition, muscle function, post-concussion assessment, cognitive testing (ImPACT) and lactic acid levels, as secondary outcomes. Twenty seven moderately trained swimmers (7 women and 20 men) participated in the study. Results: For primary outcome on 200-m front crawl at maximal speed, a significant average decrease of 2.98 seconds (p=0.022) was detected in RG group, but it was not significant compared to placebo. On 50-m front crawl at maximal speed, no statistically significant intra- or inter-group differences were detected. Regarding secondary outcomes, no difference was demonstrated between pre- performance and post-performance lactic acid levels. Comparing the treatment with placebo across follow-up, mean mid-arm muscle circumference (MAC) increased weekly and significantly by 0.23 cm (p=0.026), as well as 0.36% for gynoid fat (p=0.005). In addition, a decrease of 0.13kg in fat-free mass (p=0.067) was also detected. No statistically significant intra- or inter-group differences were detected for secondary outcomes. Conclusion: This pilot study provided early evidence that RG supplementation may positively affect nutritional status and partially, the performance of moderately trained swimmers. Further research is needed to clarify the mechanisms of action, the optimal timing of supplementation, as well as the most effective dose. Keywords: Rice germ, swimmers, nutritional supplement, lactic acid, fat-free mass __________________________ *Corresponding author: Dr. Vittoria Infantino Department of Public Health, Experimental and Forensic Medicine, Unit of Human and Clinical Nutrition c/o Azienda di Servizi alla Persona “Istituto Santa Margherita”, University of Pavia, Pavia, 27100, Italy Tel: +39-0382-381706; E-mail: viriainfantino@hotmail.it doi: https://doi.org/10.31246/mjn-2019-0071 216 Rondanelli M, Perna S, Peroni G et al. INTRODUCTION fields, considering the potential value In order to enhance the effects of training of nutrients they contain (Perretti et al., and improve performance, athletes 2003). A recent study (Rondanelli et al., often turn to nutritional supplements 2019) demonstrated that RG has a high (Knapik et al., 2016). According to the protein content (18 g per 100 g of edible American College of Sports Medicine product) with considerable amounts of (ACSM), adequate selection of nutrients essential amino acids (mainly lysine, and supplements, and adjusting intake histidine and valine, respectively), fatty according to the exercise performed, acids (mainly monounsaturated and are necessary for optimal performance polyunsaturated fatty acids at 5.65g/100g in athletes (Rodriguez et al., 2009). and 7.65g/100g, respectively), and fibre The most recent consensus from the (7 g per 100 g). Regarding water-soluble International Society for Sports Nutrition vitamins, RG has high amounts of (ISSN), American Dietetic Association thiamine (vitamin B1) and pyridoxine (ADA) and ACSM on sports nutrition (vitamin B6), while vitamin E is the main have been reviewed by Potgieter, stating fat-soluble vitamin present. Iron [77% of that a single guideline is not sufficient to Recommended Dietary Allowance (RDA)] elaborate an individualised and focused and magnesium (108% of RDA) are the nutritional management for athletes. two main minerals found in RG. The Moreover, apart from the above mentioned nutritional composition of RG is shown guidelines, sport-specific nutritional in Table 1, based on an evaluation done strategies, including quantity, structure by Chelab (Treviso, Italy). Given its great and timing of food (or supplement) nutritional value, it will be of interest intake should also be followed in for future studies to explore ways to order to maximise sports performance incorporate RG into dietary supplements and recovery (Potgieter, 2013). The aimed at increasing nutritional intake for importance of dietary supplementation a specific population, such as athletes. is of particular interest in swimming, In fact, all these nutrients contribute where athletes usually undertake a synergistically to muscle activity and training approach characterised by a play important roles in maintaining high volume of training during aerobic the health of athletes (Manore, Meyer development and high intensity training & Thompson, 2009). Currently, despite during the competition phase, coupled these characteristics, no study has with strength training (Stellingwerff, evaluated the potential beneficial effects Maughan & Burke, 2011). of RG supplementation on athletes. The size and market value of We chose swimmers as the athletes the sports supplement industry is for this study because an analysis continuing to grow, with health, safety of the mechanics and energetics of and contamination concerns (Prosser swimming revealed that different et al., 2009) becoming more pressing. factors play key roles in the success of Therefore, it is important to identify competitive swimming events (Toussaint dietary supplements that are safe and & Hollander, 1994). The reasons beyond effective in supporting swimmers. Rice the participation of master athletes in germ (RG) could be a safe and effective competitions and/or in regular exercise dietary supplement for swimmers. In are the enjoyment and its health benefits the last few years, scientific research (Tantrum & Hodge, 1993), as well as is trying to use rice waste products in the will to enhance their performance the pharmaceutical and nutraceutical (Maharam et al., 1999). With an increase Rice germ supplementation of swimmers 217 Table 1. Nutritional composition of RG Variable Rice Germ Humidity (g/100g) 10.5 Protein (g/100g) 18.2 Fats (g/100g) 17.5 Dietary fibres (g/100g) 7.0 Ashes (g/100g) 5.7 Carbohydrates (g/100g) 41.2 Energy value (kcal/100g) 409 Energy value (kJ/100g) 1711 Starch (g/100g) 25.5 Vitamin B1 (mg/100g) 5.8 Vitamin B6 (mg/100g) 0.5 Vitamin E (mg/100g) 31.9 Cadmium (mg/kg) 0.02 Iron (mg/100g) 6.2 Magnesium (mg/100g) 347.0 Lead(mg/100g) n.r. Sodium (mg/kg) 1.9 Aspartic acid (mg/100g) 95.8 Asparagine (mg/100g) 74.1 Glutamic acid (mg/100g) 130.3 Alanine (mg/100g) 41.5 Arginine (mg/100g) 115.4 Cystine (mg/100g)10 days) led to a modest time improvement and was an efficient nutritional strategy higher blood lactate concentrations in (Fouré & Bendahan, 2017). Given only half of the swimmers, while chronic this background, the purpose of this sodium citrate supplementation did not investigation was to ascertain whether provide any ergogenic effect in a group performance and nutritional status in of adolescent swimmers (Russell et al., swimmers could be improved by a five- 2014). Gao et al. (1988) and Siegler et week RG supplementation. Regarding al. (2010, 2012) have demonstrated primary outcome, performance was -1 that swimmers ingesting 0.3g·kg body evaluated by a 50-m and 200-m front mass of sodium bicarbonate (SB) one crawl at maximal speed in order to assess hour before performance enhanced both the anaerobic and aerobic energy their blood buffering potential and this contribution to swimming performance positively influenced their interval swim (Toussaint & Hollander, 1994). performance. Lindh et al. (2008) have also shown that SB supplementation MATERIALS AND METHODS (0.3g·kg-1 body mass) can improve a Study design and randomisation single 200-m freestyle performance This pilot study was parallel and placebo time in elite male competitors, most controlled, and sample size was not likely by increasing the extra-cellular determined a priori because the subjects buffering capacity. SB supplementation were >12 per arm as suggested by Julious prior to performing maximal sprint
no reviews yet
Please Login to review.