The term “food first” has been widely accepted as the preferred strategy within sport nutrition, although there is no agreed definition of this and often limited consideration of the implications. We propose that food first should mean “where practically possible, nutrient provision should come from whole foods and drinks rather than from isolated food components or dietary supplements.” There are many reasons to commend a food first strategy, including the risk of supplement contamination resulting in anti-doping violations. However, a few supplements can enhance health and/or performance, and therefore a food only approach could be inappropriate. We propose six reasons why a food only approach may not always be optimal for athletes: (a) some nutrients are difficult to obtain in sufficient quantities in the diet, or may require excessive energy intake and/or consumption of other nutrients; (b) some nutrients are abundant only in foods athletes do not eat/like; (c) the nutrient content of some foods with established ergogenic benefits is highly variable; (d) concentrated doses of some nutrients are required to correct deficiencies and/or promote immune tolerance; (e) some foods may be difficult to consume immediately before, during or immediately after exercise; and (f) tested supplements could help where there are concerns about food hygiene or contamination. In these situations, it is acceptable for the athlete to consider sports supplements providing that a comprehensive risk minimization strategy is implemented. As a consequence, it is important to stress that the correct terminology should be “food first but not always food only.”
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“Food First but Not Always Food Only”: Recommendations for Using Dietary Supplements in Sport
Graeme L. Close, Andreas M. Kasper, Neil P. Walsh, and Ronald J. Maughan
The Protective Role of Physical Fitness on Cardiometabolic Risk During Pregnancy: The GESTAtion and FITness Project
Pedro Acosta-Manzano, Francisco M. Acosta, Marta Flor-Alemany, Blanca Gavilán-Carrera, Manuel Delgado-Fernández, Laura Baena-García, Víctor Segura-Jiménez, and Virginia A. Aparicio
Physical fitness (PF) is a cornerstone of metabolic health. However, its role in maternal–fetal metabolism during pregnancy is poorly understood. The present work investigates: (i) the association of PF with maternal and fetal cardiometabolic markers, and with clustered cardiometabolic risk during pregnancy, and (ii) whether being fit counteracts cardiometabolic abnormalities associated with overweight/obesity. Several PF components (flexibility, lower and upper body strength, and cardiorespiratory fitness [CRF]) were objectively assessed in 151 pregnant women at gestational weeks 16 and 33, and an overall PF cluster score calculated. At the same times, maternal glycemic and lipid markers, cortisol, and C-reactive protein were assessed with standard biochemical methods, along with blood pressure and a proxy for insulin resistance, and a cardiometabolic risk cluster score determined. These analytes were also measured in maternal and umbilical cord arterial and venous blood collected at delivery. PF was found to be associated with several maternal and a small number of fetal cardiometabolic markers (p < .05). Lower and upper body muscle strength, CRF, overall PF (week 16), and CRF changes (weeks 16–33) were inversely associated with clustered cardiometabolic risk (p < .05). Normal weight fit women had lower values for insulin level, insulin resistance, triglycerides, low-density lipoprotein cholesterol, C-reactive protein, and diastolic blood pressure than did overweight/obese unfit women at week 16 (p < .05). In conclusion, greater PF, especially muscle strength and CRF in early–middle pregnancy, appears to be associated with a better metabolic phenotype, and may protect against maternal cardiometabolic risk. “Keep yourself fit and normal weight before and during early pregnancy” should be a key public health message.
A Food First Approach to Carbohydrate Supplementation in Endurance Exercise: A Systematic Review
Kirsty M. Reynolds, Tom Clifford, Stephen A. Mears, and Lewis J. James
This systematic review analyzed whether carbohydrate source (food vs. supplement) influenced performance and gastrointestinal (GI) symptoms during endurance exercise. Medline, SPORTDiscus, and citations were searched from inception to July 2021. Inclusion criteria were healthy, active males and females aged >18 years, investigating endurance performance, and GI symptoms after ingestion of carbohydrate from a food or supplement, <60 min before or during endurance exercise. The van Rosendale scale was used to determine risk of bias, with seven studies having low risk of bias. A total of 151 participants from 15 studies were included in the review. Three studies provided 0.6–1 g carbohydrate/kg body mass during 5–45 min precycling exercise (duration 60–70 min) while 12 studies provided 24–80 g/hr carbohydrate during exercise (60–330 min). Except one study that suggested a likely harmful effect (magnitude-based inferences) of a bar compared to a gel consumed during exercise on cycling performance, there were no differences in running (n = 1) or cycling (n = 13) performance/capacity between food and supplemental sources. Greater GI symptoms were reported with food compared with supplemental sources. Highly heterogenous study designs for carbohydrate dose and timing, as well as exercise protocol and duration, make it difficult to compare findings between studies. A further limitation results from only one study assessing running performance. Food choices of carbohydrate consumed immediately before and during endurance exercise result in similar exercise performance/capacity responses to supplemental carbohydrate sources, but may slightly increase GI symptoms in some athletes, particularly with exercise >2 hr.
Volume 32 (2022): Issue 2 (Mar 2022)
Celebrating the Professional Life of Professor Kevin D. Tipton (1961–2022)
Oliver C. Witard, Arny A. Ferrando, and Stuart M. Phillips
This invited editorial celebrates the distinguished professional life of Professor Kevin D. Tipton, who sadly passed away on January 9, 2022. Professor Tipton made an outstanding contribution to the scientific field of sport nutrition and exercise metabolism over an exceptional 30-year career. He dedicated his academic career to understanding the response of muscle protein metabolism to exercise and nutrition. The impact of his work is far-reaching with application to athletes in terms of promoting training adaptation, recovery, and performance, alongside clinical implications for injury management and healthy aging. Notable scientific contributions included the first in vivo human study to demonstrate the role of orally ingested essential amino acids in stimulating muscle protein synthesis during acute post-exercise recovery. This finding laid the foundation for future studies to interrogate the response of muscle protein synthesis to the ingestion of different protein types. Professor Tipton’s work also included investigating the maximally effective dose and timing (regarding exercise) of ingested protein for the stimulation of muscle protein synthesis. Kevin will be remembered fondly by academics, applied scientists, and students across the sport nutrition and exercise metabolism community as a leading researcher in the field, a critical thinker, and an inspirational teacher. His mission was to educate the next generation of exercise scientists by sharing his distinct wealth of knowledge accrued over three decades. Above all else, Kevin was kind, generous (with his time and knowledge), honest, and incredibly social. He was a unique character and will be greatly missed among our community but certainly never forgotten.
Acute Ketone Salts–Caffeine–Taurine–Leucine Supplementation but not Ketone Salts–Taurine–Leucine, Improves Endurance Cycling Performance
Manuel D. Quinones and Peter W.R. Lemon
Coingestion of ketone salts, caffeine and the amino acids, taurine, and leucine improves endurance exercise performance. However, there is no study comparing this coingestion to the same nutrients without caffeine. We assessed whether ketone salts–caffeine–taurine–leucine (KCT) supplementation was superior to caffeine-free ketone salts–taurine–leucine supplementation (KT), or to an isoenergetic carbohydrate placebo (CHO-PLAC). Thirteen recreationally active men (mean ± SD: 177.5 ± 6.1 cm, 75.9 ± 4.6 kg, 23 ± 3 years, 12.0 ± 5.1% body fat) completed a best effort 20-km cycling time-trial, followed 15 min later by a Wingate power cycle test, after supplementing with either KCT (approximately 7 g of beta-hydroxybutyrate, approximately 120 mg of caffeine, 2.1 g of leucine, and 2.7 g of taurine), KT (i.e., same supplement without caffeine), or isoenergetic CHO-PLAC (11 g of dextrose). Blood ketones were elevated (p < .001) after ingestion of both KCT (0.65 ± 0.12 mmol/L) and KT (0.72 ± 0.31 mmol/L) relative to CHO-PLAC (0.06 ± 0.05 mmol/L). Moreover, KCT improved (p < .003) 20-km cycling time-trial performance (37.80 ± 2.28 min), compared with CHO-PLAC (39.40 ± 3.33 min) but not versus KT (38.75 ± 2.87 min; p < .09). 20-km cycling time-trial average power output was greater with KCT (power output = 180.5 ± 28.7 W) versus both KT (170.9 ± 31.7 W; p = .049) and CHO-PLAC (164.8 ± 34.7 W; p = .001). Wingate peak power output was also greater for both KCT (1,134 ± 137 W; p = .031) and KT (1,132 ± 128 W; p = .039) versus CHO-PLAC (1,068 ± 127 W). These data suggest that the observed improved exercise performance effects of this multi-ingredient supplement containing beta-hydroxybutyrate salts, taurine, and leucine are attributed partially to the addition of caffeine.
Dietary Supplements for Athletic Performance in Women: Beta-Alanine, Caffeine, and Nitrate
Molly J. Murphy, Blake R. Rushing, Susan J. Sumner, and Anthony C. Hackney
Beta-alanine, caffeine, and nitrate are dietary supplements generally recognized by the sport and exercise science community as evidence-based ergogenic performance aids. Evidence supporting the efficacy of these supplements, however, is greatly skewed due to research being conducted primarily in men. The physiological differences between men and women, most notably in sex hormones and menstrual cycle fluctuations, make generalizing male data to the female athlete inappropriate, and potentially harmful to women. This narrative review outlines the studies conducted in women regarding the efficacy of beta-alanine, caffeine, and nitrate supplementation for performance enhancement. Only nine studies on beta-alanine, 15 on caffeine, and 10 on nitrate in healthy women under the age of 40 years conducted in normoxia conditions were identified as relevant to this research question. Evidence suggests that beta-alanine may lower the rate of perceived exertion and extend training bouts in women, leading to greater functional adaptations. Studies of caffeine in women suggest the physiological responder status and caffeine habituation may contribute to caffeine’s efficacy, with a potential plateau in the dose–response relationship of performance enhancement. Nitrate appears to vary in influence based on activity type and primary muscle group examined. However, the results summarized in the limited literature for each of these three supplements provide no consensus on dosage, timing, or efficacy for women. Furthermore, the literature lacks considerations for hormonal status and its role in metabolism. This gap in sex-based knowledge necessitates further research on these ergogenic supplements in women with greater considerations for the effects of hormonal status.
Erratum: Hurst, Saunders, & Coleman (2020)
James A. Betts
Methodology Review: A Protocol to Audit the Representation of Female Athletes in Sports Science and Sports Medicine Research
Ella S. Smith, Alannah K.A. McKay, Kathryn E. Ackerman, Rachel Harris, Kirsty J. Elliott-Sale, Trent Stellingwerff, and Louise M. Burke
Female-specific research on sports science and sports medicine (SSSM) fails to mirror the increase in participation and popularity of women’s sport. Females have historically been excluded from SSSM research, particularly because their physiological intricacy necessitates more complex study designs, longer research times, and additional costs. Consequently, most SSSM practices are based on research with men, despite potential problems in translation to females due to sexual dimorphism in biological and phenotypical parameters as well as differences in event characteristics (e.g., race distances/durations). Recognition that erroneous extrapolations may hamper the efforts of females to maximize their athletic potential has created an impetus to acknowledge and readdress the sex disparity in SSSM research. To direct the priorities for future research, it is prudent to first develop a comprehensive understanding of the gaps in current knowledge by systematically “auditing” the literature. By conducting audits of the literature to highlight underdeveloped topics or identify potential problems with the quality of research, this information can then be used to expediently direct new research activities. This paper therefore presents a standardized audit methodology to establish the representation of female athletes in subdisciplines of existing SSSM research, including a template for reporting the results of key metrics. This standardized audit process will enable comparisons over time and between research subdisciplines. This working guide provides an important step toward achieving sex equity across SSSM research, with the eventual goal of providing evidence-based recommendations specific to the female athlete.
Repeated-Sprint Exercise in the Heat Increases Indirect Markers of Gastrointestinal Damage in Well-Trained Team-Sport Athletes
Alice Wallett, Andrew McKune, David Pyne, David Bishop, Olivier Girard, Philo Saunders, and Julien Périard
Introduction: Athletes engaged in repeated-sprint training in the heat can be at an increased risk of gastrointestinal ischemia and damage in response to a redistribution of blood to working skeletal muscles and the skin. This study investigated the effects of repeated sprinting in hot and cool conditions on markers of gastrointestinal damage. Methods: Twenty-five, well-trained, nonheat acclimated male team-sport athletes completed a five-session, repeated-sprint training regimen over 7 days in either HOT (40 °C and 40% relative humidity [RH]) or COOL (20 °C and 40% RH) conditions. Participants underwent a 20-min warm-up and four sets of 5 × 6-s maximal cycling sprints, with 24-s rest and 5-min recovery between sets. Venous blood was collected pre-, post-, and 1 hr postexercise and analyzed for intestinal fatty acid binding protein, lipopolysaccharide binding protein, soluble CD14, and heat-shock protein. Results: Intestinal fatty acid binding protein concentrations were significantly increased (p < .004) postexercise (593 and 454 pg/ml) and 1 hr postexercise (466 and 410 pg/ml) on both Days 1 and 5 in HOT. Soluble CD14 increased by 398 and 308 ng/ml postexercise (p = .041), and lipopolysaccharide binding protein increased by 1,694 ng/ml postexercise on Day 1 in HOT (p < .05) and by 1,520 ng/ml on Day 5 in COOL (p = .026). Core and skin temperature, rating of perceived exertion, and thermal sensation were higher (p < .05) in HOT on Days 1 and 5 during sprinting. Conclusions: Repeated sprinting in the heat induced greater thermal strain and mild changes in gastrointestinal damage, likely attributable to the combination of environmental conditions and maximal-intensity exercise.
