Bronwen Lundy

The Effect of Variable Doses of Inorganic Nitrate-Rich Beetroot Juice on Simulated 2000-m Rowing Performance in Trained Athletes

CONTEXT Beetroot juice is a naturally rich source of inorganic nitrate (NO(3-)), a compound hypothesized to enhance endurance performance by improving exercise efficiency. PURPOSE To investigate the effect of different doses of beetroot juice on 2000-m ergometer-rowing performance in highly trained athletes. METHODS Ten highly trained male rowers volunteered to participate in a placebo-controlled, double-blinded crossover study. Two hours before undertaking a 2000-m rowing-ergometer test, subjects consumed beetroot juice containing 0 mmol (placebo), 4.2 mmol (SINGLE), or 8.4 mmol (DOUBLE) NO(3-). Blood samples were taken before supplement ingestion and immediately before the rowing test for analysis of plasma [NO(3-)] and [nitrite (NO(2-))]. RESULTS The SINGLE dose demonstrated a trivial effect on time to complete 2000 m compared with placebo (mean difference: 0.2 ± 2.5 s). A possibly beneficial effect was found with DOUBLE compared with SINGLE (mean difference -1.8 ± 2.1 s) and with placebo (-1.6 ± 1.6 s). Plasma [NO(2-)] and [NO(3-)] demonstrated a dose-response effect, with greater amounts of ingested nitrate leading to substantially higher concentrations (DOUBLE > SINGLE > placebo). There was a moderate but insignificant correlation (r = -.593, P = .055) between change in plasma [NO(2-)] and performance time. CONCLUSION Compared with nitratedepleted beetroot juice, a high (8.4 mmol NO(3-)) but not moderate (4.2 mmol NO(3-)) dose of NO(3-) in beetroot juice, consumed 2 h before exercise, may improve 2000-m rowing performance in highly trained athletes.

A multifactorial evaluation of illness risk factors in athletes preparing for the Summer Olympic Games

OBJECTIVES Illness can disrupt training and competition performance of athletes. Few studies have quantified the relative contribution of the known medical, behavioural and lifestyle risk factors. DESIGN Cross-sectional. METHODS Olympic athletes from 11 sports (n=221) were invited to complete questionnaires administered nine months before the Rio 2016 Olympic Games. These included the Depression, Anxiety and Stress Questionnaire (DASS-21), Perceived Stress Scale (PSS), Dispositional Resilience Scale (DRS), Recovery-Stress Questionnaire (REST-Q-52 item), Low Energy in Females Questionnaire (LEAF-Q), a modified Personal and Household Hygiene questionnaire, Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index, and custom-made questionnaires on probiotic usage and travel. An illness (case) was defined as an event which limited training or competition for greater hours in the prior month. Odds ratios and attributable fractions in the population (AFP) were utilised for categorical variables with independent t-tests or Wilcoxon rank-sum for continuous variables. RESULTS Eighty-one athletes responded (male, n=26; female, n=55). There were 16 illness cases and 65 controls. Female athletes were at higher odds of illness (OR=9.4, 95%CI 1.3-410, p=0.01, AFP=0.84). Low energy availability (LEAF-Q score ≥8: OR=7.4, 95%CI 0.78-352, p=0.04, AFP=0.76), depression symptoms (DASS-21: depression score >4, OR=8.4, 95%CI 1.1-59, p<0.01; AFP=0.39) and higher perceived stress (PSS: 10-item, p=0.04) were significantly associated with illness. CONCLUSIONS Female sex, low energy availability, and mental health are associated with sports incapacity (time loss) due to illness. Low energy availability had high attributable fractions in the population and stands out as a primary association with illness.

New approaches to determine fatigue in elite athletes during intensified training: resting metabolic rate and pacing profile

Background Elite rowers complete a high volume of training across a number of modalities to prepare for competition, including periods of intensified load, which may lead to fatigue and short-term performance decrements. As yet, the influence of substantial fatigue on resting metabolic rate (RMR) and exercise regulation (pacing), and their subsequent utility as monitoring parameters, has not been explicitly investigated in elite endurance athletes. Method Ten National-level rowers completed a four-week period of intensified training. RMR, body composition and energy intake were assessed PRE and POST the four-week period using indirect calorimetry, Dual-Energy X-Ray Densitometry (DXA), and three-day food diary, respectively. On-water rowing performance and pacing strategy was evaluated from 5 km time trials. Wellness was assessed weekly using the Multicomponent Training Distress Scale (MTDS). Results Significant decreases in absolute (mean ± SD of difference, p-value: -466 ± 488 kJ.day-1, p = 0.01) and relative RMR (-8.0 ± 8.1 kJ.kg.FFM-1, p = 0.01) were observed. Significant reductions in body mass (-1.6 ± 1.3 kg, p = 0.003) and fat mass (-2.2 ± 1.2 kg, p = 0.0001) were detected, while energy intake was unchanged. On-water 5 km rowing performance worsened (p < 0.05) and an altered pacing strategy was evident. Fatigue and total mood disturbance significantly increased across the cycle (p < 0.05), and trends were observed for reduced vigour and increased sleep disturbance (p < 0.1). Conclusion Four weeks of heavy training decreased RMR and body composition variables in elite rowers and induced substantial fatigue, likely related to an imbalance between energy intake and output. This study demonstrates that highly experienced athletes do not necessarily select the correct energy intake during periods of intensified training, and this can be assessed by reductions in RMR and body composition. The shortfall in energy availability likely affected recovery from training and altered 5 km time trial pacing strategy, resulting in reduced performance.

Prevalence of illness, poor mental health and sleep quality and low energy availability prior to the 2016 Summer Olympic Games

Objective Establish the prevalence of illness symptoms, poor sleep quality, poor mental health symptoms, low energy availability and stress-recovery state in an Olympic cohort late in the 3 months prior to the Summer Olympic Games. Methods Olympic athletes (n=317) from 11 sports were invited to complete questionnaires administered 3 months before the Rio 2016 Olympic Games. These questionnaires included the Depression, Anxiety and Stress Questionnaire, Perceived Stress Scale, Dispositional Resilience Scale, Recovery-Stress Questionnaire (REST-Q-52 item), Low Energy Availability in Females Questionnaire (LEAF-Q), Epworth Sleepiness Scale, Pittsburgh Sleep Quality Index and custom-made questionnaires on probiotic usage and travel. Multiple illness (case) definitions were applied. ORs and attributable fractions in the population were used. Factor analyses were used to explore the relationships between variables. Results The response rate was of 42% (male, n=47, age 25.8±4.1 years; female, n=85, age 24.3±3.9 years). Low energy availability was associated with sustaining an illness in the previous month (upper respiratory, OR=3.8, 95% CI 1.2 to 12). The main factor relating to illness pertained to a combination of anxiety and stress-recovery states (as measured by the REST-Q-52 item). All participants reported at least one episode of illness in the last month (100% prevalence). Conclusions All participants reported at least one illness symptom in the previous month. Low energy availability was a leading variable associated with illness in Olympic-class athletes. The estimates duration of symptoms ranged from 2 to 7 days. Factor analyses show the interdependence of various health domains and support multidisciplinary care.

IOC consensus statement on relative energy deficiency in sport (RED-S): 2018 update

In 2014, the IOC published a consensus statement entitled ‘Beyond the Female Athlete Triad: Relative Energy Deficiency in Sport (RED-S)’. The syndrome of RED-S refers to ‘impaired physiological functioning caused by relative energy deficiency and includes, but is not limited to, impairments of metabolic rate, menstrual function, bone health, immunity, protein synthesis and cardiovascular health’. The aetiological factor of this syndrome is low energy availability (LEA).1 The publication of the RED-S consensus statement stimulated activity in the field of Female Athlete Triad science, including some initial controversy2 3 followed by numerous scientific publications addressing: 1. The health parameters identified in the RED-S conceptual model (figure 1).1 4 2. Relative energy deficiency in male athletes. 3. The measurement of LEA. 4. The performance parameters identified in the RED-S conceptual model (figure 2).1 4 The IOC RED-S consensus authors have reconvened to provide an update summary of the interim scientific progress in the field of relative energy deficiency with the ultimate goal of stimulating advances in RED-S awareness, clinical application and scientific research to address current gaps in knowledge. Figure 1 Health consequences of Relative Energy Deficiency in Sport (RED-S) showing an expanded concept of the Female Athlete Triad to acknowledge a wider range of outcomes and the application to male athletes (*Psychological consequences can either precede RED-S or be the result of RED-S).1 4 Figure 2 Potential Performance consequences of Relative Energy Deficiency in Sport (*Aerobic and anerobic performance).1 4 ### Low energy availability LEA, which underpins the concept of RED-S, is a mismatch between an athlete’s energy intake (diet) and the energy expended in exercise, leaving inadequate energy to support the functions required by the body to maintain optimal health and performance. Operationally, energy availability (EA) is defined as: ![Formula][1] where exercise energy expenditure (EEE) is calculated as the additional energy expended above that of … [1]: /embed/mml-math-1.gif

The effects of intensified training on resting metabolic rate (RMR), body composition and performance in trained cyclists

Background Recent research has demonstrated decreases in resting metabolic rate (RMR), body composition and performance following a period of intensified training in elite athletes, however the underlying mechanisms of change remain unclear. Therefore, the aim of the present study was to investigate how an intensified training period, designed to elicit overreaching, affects RMR, body composition, and performance in trained endurance athletes, and to elucidate underlying mechanisms. Method Thirteen (n = 13) trained male cyclists completed a six-week training program consisting of a “Baseline” week (100% of regular training load), a “Build” week (~120% of Baseline load), two “Loading” weeks (~140, 150% of Baseline load, respectively) and two “Recovery” weeks (~80% of Baseline load). Training comprised of a combination of laboratory based interval sessions and on-road cycling. RMR, body composition, energy intake, appetite, heart rate variability (HRV), cycling performance, biochemical markers and mood responses were assessed at multiple time points throughout the six-week period. Data were analysed using a linear mixed modeling approach. Results The intensified training period elicited significant decreases in RMR (F(5,123.36) = 12.0947, p = <0.001), body mass (F(2,19.242) = 4.3362, p = 0.03), fat mass (F(2,20.35) = 56.2494, p = <0.001) and HRV (F(2,22.608) = 6.5212, p = 0.005); all of which improved following a period of recovery. A state of overreaching was induced, as identified by a reduction in anaerobic performance (F(5,121.87) = 8.2622, p = <0.001), aerobic performance (F(5,118.26) = 2.766, p = 0.02) and increase in total mood disturbance (F(5, 110.61) = 8.1159, p = <0.001). Conclusion Intensified training periods elicit greater energy demands in trained cyclists, which, if not sufficiently compensated with increased dietary intake, appears to provoke a cascade of metabolic, hormonal and neural responses in an attempt to restore homeostasis and conserve energy. The proactive monitoring of energy intake, power output, mood state, body mass and HRV during intensified training periods may alleviate fatigue and attenuate the observed decrease in RMR, providing more optimal conditions for a positive training adaptation.

International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S): 2018 Update

International Olympic Committee (IOC) Consensus Statement on Relative Energy Deficiency in Sport (RED-S) : 2018 Update

Bone mineral density in elite rowers

Methods Subjects (n=125) were internationally competitive. Between 2011-2014 BMD was taken at the lumbar spine (L1-L4) and left femur, by Dual-energy X-ray absorptiometry (DXA, Lunar Prodigy, GE Healthcare), using the same scanner, and a qualified technician. Ethics was approved by the Australian Institute of Sport Human Ethics committee. Subjects gave prior written informed consent. Descriptive statistics are reported as mean ± standard deviation (range), Z-score and T-score. Statistical analysis was performed using independent samples t-test, significance set at p<0.05.

A–Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance: Part 41

Vitamin preparations have been a stalwart of the supplement industry. They reflect both our understanding that they are, by definition, essential for optimal health and function, as well as our fears that either the food supply, or the way we consume it, fails to provide us with optimal amounts of these micronutrients. In the case of B-vitamins, the greatest research interest in supplementation occurred around World War II, tied to the reasonably new discovery of many of these vitamins and the interest in adequate war rations and military feeding plans. Even with the more targeted interest in sports nutrition, the topic of vitamin supplementation seems dated, with most available studies dating back to the early 1990s. The interest in vitamin K in sports nutrition, however, is more contemporary, due to its role in bone health. ### M K Ranchordas The B-vitamins are water-soluble vitamins that play crucial roles in energy metabolism. There are eight B-vitamins: thiamine (B1), riboflavin (B2), niacin (B3), pantothenic acid (B5) pyridoxine (B6), biotin (B7), involved in energy-producing pathways; folic acid (B9), cobalamin (B12) involved in synthesising new cells, red blood cells and in cell repair. The richest sources of B-vitamins are unprocessed foods such as whole grains, green leafy vegetables, nuts, dairy products and animal foods such as meat and eggs but, in many countries, foods such as cereals and bread are fortified with these vitamins. It has been reported that inadequate intake and deficiencies in B-vitamins could impair athletic performance.1 ,2 Studies examining dietary intakes of B-vitamins in …

A–Z of nutritional supplements: dietary supplements, sports nutrition foods and ergogenic aids for health and performance – Part 25

Part 25 contains a variety of topics, ranging from the sleep enhancer, melatonin, to an unlikely addition to the M section of our alphabetical series, namely melamine. It is not known how many athletes take melatonin in order to combat sleep deprivation on the necessary long-haul flights they make to compete all over the world. It is more readily available in some countries than others. Methylsulphonylmethane (MSM) has long been used as a supplement for pain relief in a variety of autoimmune diseases. Rather unexpectedly, MSM is used by athletes to combat snoring. We decided to provide a very brief article on melamine, which most of us only think of as a substance important to the manufacture of good-quality picnic ware! However, athletes need to be aware of its history as a possible contaminant of high protein products. ### B Lundy, JC Miller Melatonin ( N -acetyl-5-methoxytryptamine) is a pineal gland hormone with effects upon circadian rhythms, sleep onset and reproductive systems.1 2 Blood levels of melatonin are generally undetectable during daytime, but rise sharply during darkness. Light–dark sensations at the retina are relayed to the suprachiasmatic nucleus of the hypothalamus. Fibres from the hypothalamus descend to the spinal cord and ultimately project to the superior cervical ganglia, from which sympathetic postganglionic neurons ascend back to the pineal gland. Melatonin peak amplitudes decrease with age,3 which may explain the flattening of the circadian rhythm also associated with ageing. Melatonin is well known as an antioxidant, immunomodulator and anticancer agent.2 Melatonin is of …