%). The most commonly used daily dietary supplements were proteins (29%) and multivitamins (21%) (Table 6 ). Table 6 Type and Frequency of Dietary Supplement Use by Athletes Types of dietary supplement Never used Daily When it is needed When I am sick Occasionally Calcium 289 (67) 55 (13) 65 (15) 12 (3
Hanan A. Alfawaz, Soundararajan Krishnaswamy, Latifah Al-Faifi, Halima Ali Bin Atta, Mohammad Al-Shayaa, Saad A. Alghanim and Nasser M. Al-Daghri
Mark Messina, Heidi Lynch, Jared M. Dickinson and Katharine E. Reed
For a variety of reasons, dietary protein has gained increased research attention in recent years. Evidence shows that consuming protein in excess of the U.S. recommended dietary allowance has health benefits and that for many population groups, the recommended dietary allowance of protein (0.8 g
Luc J.C. van Loon, Arie K. Kies and Wim H.M. Saris
With the increasing knowledge about the role of nutrition in increasing exercise performance, it has become clear over the last 2 decades that amino acids, protein, and protein hydrolysates can play an important role. Most of the attention has been focused on their effects at a muscular level. As these nutrients are ingested, however, it also means that gastrointestinal digestibility and absorption can modulate their effcacy significantly. Therefore, discussing the role of amino acids, protein, and protein hydrolysates in sports nutrition entails holding a discussion on all levels of the metabolic route. On May 28–29, 2007, a small group of researchers active in the field of exercise science and protein metabolism presented an overview of the different aspects of the application of protein and protein hydrolysates in sports nutrition. In addition, they were asked to share their opinions on the future progress in their fields of research. In this overview, an introduction to the workshop and a short summary of its outcome is provided.
Amy J. Hector and Stuart M. Phillips
restriction, strategies to promote high-quality weight loss (i.e., the loss of fat mass while maintaining LBM) are of importance for elite athletes. The normal maintenance of LBM is determined by continuously opposing and fluctuating rates of muscle protein synthesis (MPS) and muscle protein breakdown (MPB
Oliver C. Witard, Ina Garthe and Stuart M. Phillips
Dietary protein is widely regarded as a key nutrient for allowing optimal training adaptation ( Tipton, 2008 ) and optimizing body composition ( Hector & Phillips, 2018 ; Murphy et al., 2015 ) in athletes including track and field athletes. Track and field athletics encompasses a broad spectrum of
Luc J.C. van Loon
Protein, protein hydrolysates, and amino acids have become popular ingredients in sports nutrition. The use of protein, protein hydrolysates, and amino acid mixtures has multiple applications when aiming to improve post exercise recovery. After exhaustive endurance-type exercise, muscle glycogen repletion is the most important factor determining the time needed to recover. Coingestion of relatively small amounts of protein and/or amino acids with carbohydrate can be used to augment postprandial insulin secretion and accelerate muscle glycogen synthesis rates. Furthermore, it has been well established that ingesting protein, protein hydrolysates, and amino acid can stimulate protein synthesis and inhibit protein breakdown and, as such, improve net muscle protein balance after resistance- or endurance-type exercise. The latter has been suggested to lead to a more effective adaptive response to each successive exercise bout. To augment net muscle protein accretion, athletes involved in resistance-type exercise generally ingest both protein and carbohydrate during post exercise recovery. However, carbohydrate ingestion after resistance-type exercise does not seem to be warranted to further stimulate muscle protein synthesis or improve whole-body protein balance when ample protein has already been ingested. Because resistance-type exercise is also associated with a substantial reduction in muscle glycogen content, it would be preferred to coingest some carbohydrate when aiming to accelerate glycogen repletion. More research is warranted to assess the impact of ingesting different proteins, protein hydrolysates, and/or amino acids on muscle protein accretion after exercise.
Christina Tsitsimpikou, Nastasia Chrisostomou, Peter Papalexis, Konstantinos Tsarouhas, Aristidis Tsatsakis and Athanasios Jamurtas
Although the use of nutritional supplements by professional athletes and the benefits thereof have been extensively studied, information on recreational athletes’ use of supplements is limited. This study investigated the consumption of nutritional supplements, source of information and supply of supplements, and level of awareness with regard to the relevant legislation among individuals who undertake regular exercise in Athens, Greece. A closed-ended, anonymous questionnaire was answered by 329 subjects (180 men, 149 women), age 30.6 ± 12.1 yr, from 11 randomly selected gym centers. Preparations declared as anabolic agents by the users were submitted to a gas chromatographic analyzer coupled to a mass spectrometric detector. Consumption of nutritional supplements was reported by 41% of the study population, with proteins/amino acids and vitamins being the most popular. Age (r = .456, p = .035), sex (χ2 = 14.1, df = 1, p < .001), level of education (χ2 = 14.1, df = 3, p < .001), and profession (χ2 = 11.4, df = 4, p = .022) were associated with the subjects’ decision to consume nutritional supplements. Most (67.1%) purchased products from health food stores. Only 17.1% had consulted a physician or nutritionist, and one third were aware of the relevant legislation. Two preparations were detected containing synthetic anabolic steroids not stated on the label. In conclusion, use of nutritional supplements was common among recreational athletes in Athens, Greece. A low level of awareness and low involvement of health care professionals as sources of information and supply were observed.
Megan Colletto and Nancy Rodriguez
; Paddon-Jones & Rasmussen, 2009 ). Physical activity, strength training in particular, improves whole body protein balance (WBPB) in older individuals ( Timmerman et al., 2012 ; Walker et al., 2011 ). Of significance to this investigation is the potential of yoga as an alternative exercise option for the
William Abbott, Adam Brett, Emma Cockburn and Tom Clifford
to accelerate the remodeling process. 3 One of the most frequently recommended strategies to stimulate the latter is immediate protein feeding. 3 , 4 Indeed, a number of recent reviews on the topic recommend that players consume 20 to 40 g or 0.25 to 0.4 g/kg of high-quality protein as soon as
Mads S. Larsen, Dagmar Clausen, Astrid Ank Jørgensen, Ulla R. Mikkelsen and Mette Hansen
overuse injuries, efficient muscle recovery is of special importance during such periods. Although the cellular mechanisms driving the acute regenerative processes are not well elucidated, a growing number of studies have unveiled the benefits of protein feeding strategies in regard to optimizing recovery