Purpose of Review
Adequate nutrition knowledge may influence dietary behaviour, and the performance and health of athletes. Assessment of the nutrition knowledge of athletes can inform practice and ...provide a quantitative way to evaluate education interventions. This article aims to review nutrition knowledge questionnaires published in the last 5 years to identify advances, possible improvements in questionnaire development and design, and challenges that remain.
Recent Findings
Twelve new or modified questionnaires were identified. All had undergone validity and reliability testing. Advancements included quantitative measures of content validity and Rasch analysis. Online questionnaires were common, with at least seven using this format. Advances included use of images (
n
= 2), automated scored feedback (
n
= 1), and use of applied questions.
Summary
While advancements have been made in validation and reliability testing and electronic delivery, new questionnaires would benefit from interactive and attractive features including images, provision of electronic feedback, and applied questions.
The primary aim of this study was to investigate the effects of increased dietary cholesterol intake through the consumption of two eggs per day on biomarkers of bone metabolism and inflammation in ...female division one cross country and track athletes.
Fifteen female Division I student-athletes from university’s women’s Cross Country/Track and Field Team (age 20.2 + 1.0 yrs.) participated in this study. Prior to the study, subjects were asked to refrain from all egg-based food products for two weeks. After this initial period, subjects were instructed to consume two eggs per day in the form of their choice for 12 weeks. Fasting venous blood samples were collected in the morning hours (0700–1000) following a 12-hour fast and absence of intense exercise training within the last 24 hrs at baseline and after 12 weeks. Serum was collected and immediately stored at -80°C until analysis. Serum bone formation markers; N-terminal propeptide of type I procollagen (PINP) and osteocalcin (OC) and bone resorption marker, C-terminal of telopeptides of type I procollagen (CTXI), and serum inflammatory biomarkers; tumor necrosis factor alpha (TNF-α), interleukin-1 beta (IL-1 β), and IL-6 were measured using ELISA kits.
There were no significant changes in any of the bone metabolism biomarkers, but they were trending in a positive direction. Mean serum CTXI levels were slightly lower at 0.36 vs 0.30 ng/mL after the intervention, but not significantly (p = 0.083). Serum OC levels didn’t change 0.35 vs 0.38 ng/mL nor did serum PINP levels, 40.89 vs 42.72 ng/mL after the intervention. For the biomarkers of inflammation we did observe a significant increase in serum IL-6, 3.82 vs 4.27 pg/mL (p = 0.037) after the intervention. However, there were no significant changes in TNF-α, 10.27 vs 9.70 pg/mL or IL-1β, 5.97 vs 6.05 pg/mL after the intervention.
The current study shows no substantial changes in serum biomarkers of bone metabolism or inflammation after intervention with consuming two eggs per day for 12 weeks. However, there was a significant increase in IL-6 after the intervention.
Supported in part by an Internal Seed Research Grant from the University of Massachusetts Lowell.
This systematic review, meta-analysis, and meta-regression aimed to determine if increasing daily protein ingestion contributes to gaining lean mass (LM), muscle strength, and physical/functional ...test performance in healthy persons.
The present review was registered on PROSPERO - CRD42020159001. A systematic search in Medline, Embase, CINAHL, and Web of Sciences databases was undertaken. Randomized controlled trials (RCT) including healthy and non-obese adult participants increasing daily protein intake were selected. Subgroup analysis, splitting the studies by participation in resistance exercise training (RE), age (< 65 or ≥ 65 y), and daily protein ingestion were also performed.
74 RCT fit our inclusion criteria. The age range of the participants was 19 to 85 y, and study protocols in the trials lasted from 6 to 108 wks (76% of the studies between 8 and 12 wks). In ∼80% of the studies, baseline protein ingestion was at least 1.2 g of protein/kg/d. Increasing daily protein ingestion may lead to small gains in LM in subjects enrolled in RE (SMD standardized mean difference = 0.22, CI95% 95% confidence interval 0.14:0.30, P < 0.01, 62 studies, moderate level of evidence). Also, ≥ 65 y subjects ingesting 1.2–1.59 g of protein/kg/d and younger subjects (< 65 y) increasing their ingestion to ≥ 1.6 g of protein/kg/d during RE showed a higher LM gain. Lower-body strength gain was slightly higher at ≥ 1.6 g of protein/kg/d during RE (SMD = 0.40, CI95% 0.09:0.35, P < 0.01, 19 studies, low level of evidence). Bench press strength was slightly increased by ingesting more protein in < 65 y subjects during RE (SMD = 0.18, CI95% 0.03:0.33, P = 0.01, 32 studies, low level of evidence). Effects on handgrip strength are unclear and only marginal for performance in physical function tests.
The number of studies increasing daily protein ingestion alone was too low (n = 6) to conduct a meta-analysis. The current evidence shows that increasing protein ingestion by consuming supplements or food, resulted in small additional gain in LM, and lower body muscle strength in healthy adults enrolled in RE. Effects on bench press strength and performance in physical function tests are minimal. The effect on handgrip strength was unclear.
This research received a grant from the International Life Science Institute (Europe) and CNPq.
This study aimed to examine the protective effects of Aronia melanocarna berry extract (ABE) supplementation against the acute aerobic exercise (AAE) – induced oxidative stress in healthy subjects.
A ...8-week, randomized, double-blind, parallel, placebo-controlled trial were conducted with 70 healthy middle-aged adults. We assessed a battery of AAE-induced oxidate stress biomarkers at pre-exercise, immediately post-exercise, and 30-min post-exercise. The AAE challenge model, as a treadmill exercise for 30 minutes at 60% VO2max, was applied to load oxidative stress at the end of the study. A linear mixed-effect model was used to test differences of safety and effectiveness between two groups and Pearson’s correlation coefficients assessed the statistical association.
The AAE-induced time course-dependent oxidative stress was well-observed in the placebo group regarding the glutathione peroxidase activity and glutathione availability for antioxidant defense; and erythrocyte malondialdehyde, interleukin-6, and lactate levels for oxidative damage. Meanwhile, the ABE supplementation improved the glutathione defense system by increasing glutathione availability and glutathione peroxidase activity during exercise and post-exercise recovery periods. In addition, the scatter plot and linear regression analysis revealed strong negative correlations of GSH availability with oxidized LDL and erythrocyte malonaldehyde levels.
These finding suggest ABE supplementation might affect to improve antioxidant defense mechanism in healthy adults with low fruit and vegetable intake.
This research was supported by the BK21 FOUR (Fostering Outstanding Universities for Research) funded by the Ministry of Education (MOE, Korea) and the National Research Foundation of Korea (NRF), and the Bio & Medical Technology Development Program of the National Research Foundation (NRF), funded by the Ministry of Science & ICT (2012M3A9C4048761).
Plant-based eating (PBE), emphasizing grains, legumes, and fruits and vegetables, is linked to chronic disease prevention, positive environmental impacts, and sound animal ethics. Misconceptions of ...PBE and how PBE affects performance and recovery may prevent athletes from following a dietary pattern that promotes good health and environmental sustainability. The objectives of this study were to: (1) determine if competitive athletes’ definitions of PBE are consistent with those of current North American nutrition guidelines, and (2) understand if competitive athletes’ motivations to follow PBE are related to perceived impacts on performance in their sport.
Twenty male and female athletes (18 years or older) competing in university sports at 4 Canadian post-secondary schools completed an online questionnaire consisting of open-ended questions on personal definitions, practices, and concerns with PBE. Responses were analyzed using grounded theory, and thematic and content analysis was used to find commonalities amongst responses. Data was analyzed by a research team consisting of an experienced qualitative researcher, a senior researcher, and a senior undergraduate student.
Definitions of PBE amongst athletes varied; however, the majority viewed PBE as complete omission of meat or animal products. 16 participants indicated that they did not follow PBE. A theme of uncertainty of the effects of PBE on performance emerged from the data (“I don’t know where I would get the strength to finish workouts” and “I understand that eating fruits and vegetables is important for general health, but I also think that a high protein diet, which is easily obtained by eating meat, is important as well).” A theme of openness to trying PBE was also apparent from the data, with athletes reporting that they would follow PBE if it helped them achieve their nutrition goals and induced a noticeable difference in the way they felt.
Misconceptions and lack of knowledge of PBE and its effects on performance may lead athletes to overlook PBE as a viable option. Future nutrition education for athletes should promote clear definitions of PBE and how emphasizing plant-based foods can support both athletic performance and optimal health.
This study was unfunded by an internal grant from The University of Winnipeg.
Variation in muscle damage following eccentric exercise is wide-ranging and largely unexplained. This study investigated linkages between eccentric exercise-induced increases in the muscle damage ...biomarker creatine kinase (CK) and diet quality, body composition and fitness test performance, diagnostic chemistries, oxidative stress, and inflammation.
Participants included 53 healthy, non-obese male (n = 30) and female adults (n = 23) (20–55 y, BMI < 30 kg/m2) who were not engaged in regular resistance training. After familiarization, participants engaged in a 90-min bout of whole-body eccentric exercise (90-EE) (17 exercises). Changes in muscle soreness (DOMS, 1–10 scale) and damage biomarkers (serum CK, myoglobin), exercise performance, oxidative stress (4-hydroxynonenal or 4HNE), inflammation (CRP, IL-18, IL-16, IL-10), serum cortisol, and diagnostic chemistries were monitored immediately post-90-EE, and then each morning during a 4-d recovery period. Blood samples were collected in an overnight fasted state, with serum CK, myoglobin, cortisol, and diagnostic chemistries measured at a clinical lab. IL-18, IL-6, IL-10, and 4HNE were assayed by ELISA. Participants entered food and beverage intake in 3-d food records with nutrient and flavonoid intake assessed and the Food Nutrient Index (FNI) calculated using eight under-consumed nutrients.
The 90-EE bout induced significant DOMS and muscle damage, inflammation and oxidative stress, and decreases in strength and anaerobic power. CK increased throughout the 4-d recovery period, with the highest levels measured on the 4th day (range, 60–17,040 U/L; mean ± SD, 1,565 ± 3,132 U/L). CK was correlated with other tissue damage biomarkers including aspartate aminotransferase (r = 0.946), lactate dehydrogenase (r = 0.884), and myoglobin (r = 0.763). Under linear regression analysis with non-tissue damage outcomes including FNI (68.7 ± 15.7), DOMS and serum cortisol emerged as the best predictors of post-90-EE CK variance R2 = 0.367, F(2,50) = 14.48, p < 0.001.
The CK response to 90-EE varied widely between participants with 37% of the variance related to perceptions of muscle soreness and the stress hormone cortisol, but not diet quality, inflammation, oxidative stress, or fitness test performance.
MegaFood.
This study with untrained adults determined if 4-weeks supplementation with almonds compared to a matched calorie, common snack (cereal bars) had an influence on exercise performance, muscle soreness ...and damage, and mood states during a 4-d period after engaging in an acute, 90-min bout of eccentric exercise (90-EE).
Participants included 64 healthy, non-obese male and female adults (30–65 years, BMI 23–30 kg/m2) who were not engaged in regular resistance training. Participants were randomized to almond (57 g/d) (AL) and cereal bar (324 kcal/d) (CB) groups for 4 weeks prior to engaging in 90-EE (17 exercises). Changes in muscle soreness and damage biomarkers, exercise performance tests, and mood states were monitored before and after the 4-week supplementation period, immediately post-90-EE, and then each morning during a 4-d recovery period.
The 90-EE caused significant delayed onset of muscle soreness that peaked 1–2-d post-exercise with no group differences (time, p < 0.001, interaction, p = 0.187). Serum muscle damage biomarkers increased strongly in both groups but were significantly lower in AL vs. CB immediately post-90-EE (creatine kinase, p = 0.034, myoglobin, p = 0.036) and after 1-d recovery (creatine kinase, p = 0.013). Several measures of performance were negatively affected by 90-EE including the 60-yard shuttle run time, leg-back strength, bench press repetitions, and peak- and mean-power during the 30-sec Wingate test (all p < 0.01). AL vs. CB had higher levels of leg-back strength during recovery (interaction, p = 0.029), but the groups did not differ in other performance measures. Total mood disturbance (TMD) and fatigue increased post-90-EE, but the magnitude of these changes tended to be lower in AL vs. CB (interaction, p = 0.130, p = 0.051, respectively). Vigor was higher immediately post-90-EE in AL vs. CB (p = 0.060).
The 90-EE protocol induced significant muscle damage, muscle soreness, reduced strength and power performance, and mood disturbance. AL vs. CB ingestion (4 weeks) was linked to reduced serum levels of muscle damage, higher levels of leg/back strength, and a lower magnitude of mood disturbance. Thus, chronic almond ingestion may help mitigate negative physiological and mental responses to unaccustomed exercise by untrained individuals.
Almond Board of California.
Current literature suggests law enforcement officers have high rates of obesity. With diet as a leading risk factor, early career nutrition interventions could be beneficial in establishing long-term ...healthy eating habits. Thus, the purpose of this study was to determine the diet quality (DQ) and performance nutrition adequacy of a state police academy’s dining facility menu.
This cross-sectional content analysis included six weeks (three daily meals, Monday–Friday) of a state police academy’s dining facility menu. Nutrient content was determined by meeting with the dining facility manager, portioning menus, gathering food specifications from purchase orders, and then performing nutrient analysis. DQ was assessed using the Healthy Eating Index-2015 (HEI). Independent t-test and Cohen’s d determined differences between menu nutrient content and performance nutrient needs.
The mean (±SD) total HEI score for the six-week menu was 54 ± 9.55 out of 100. Subcomponent scores of total protein (4.97 out of 5) and whole fruits (4.77 out of 5) indicate adequacy. Total fruit (3.19 out of 5), whole grains (6.10 out of 10), total vegetable (3.77 out of 5), and dark greens and legumes (3.51 out of 5) scores could be improved. Seafood and plant proteins (0.33 out of 5), fatty acid ratio (1.31 out of 5), and dairy (1.59 out of 10) scores were low. The menu met recommended intake for 13 of 19 subcomponents investigated. Subcomponents that did not meet adequacy were calories (% mean difference, needs – menu = 36.7%), carbohydrates (% mean difference = 52.3%), vitamins D (% mean difference = 82.5%) and E (% mean difference = 66.7%), magnesium (% mean difference = 44.1%), and potassium (% mean difference = 41.8%).
The academy menu is adequate in most performance-related nutrients, but also leaves room for improvement in DQ and shortfall nutrients. By focusing on increasing low HEI subcategory scores, overall DQ of the menu will increase and could potentially simultaneously make up for inadequate nutrients. To optimize current and future performance and health, police academies should consider evaluating their menus and ensuring adequacy and high DQ.
None.
Key points
Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support.
Adaptation to a ketogenic low ...carbohydrate, high fat (LCHF) diet markedly increases rates of whole‐body fat oxidation during exercise in race walkers over a range of exercise intensities.
The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real‐life race performance in elite race walkers.
In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity.
We investigated the effects of adaptation to a ketogenic low carbohydrate (CHO), high fat diet (LCHF) during 3 weeks of intensified training on metabolism and performance of world‐class endurance athletes. We controlled three isoenergetic diets in elite race walkers: high CHO availability (g kg−1 day−1: 8.6 CHO, 2.1 protein, 1.2 fat) consumed before, during and after training (HCHO, n = 9); identical macronutrient intake, periodised within or between days to alternate between low and high CHO availability (PCHO, n = 10); LCHF (< 50 g day−1 CHO; 78% energy as fat; 2.1 g kg−1 day−1 protein; LCHF, n = 10). Post‐intervention, V̇O2 peak during race walking increased in all groups (P < 0.001, 90% CI: 2.55, 5.20%). LCHF was associated with markedly increased rates of whole‐body fat oxidation, attaining peak rates of 1.57 ± 0.32 g min−1 during 2 h of walking at ∼80% V̇O2 peak . However, LCHF also increased the oxygen (O2) cost of race walking at velocities relevant to real‐life race performance: O2 uptake (expressed as a percentage of new V̇O2 peak ) at a speed approximating 20 km race pace was reduced in HCHO and PCHO (90% CI: −7.047, −2.55 and −5.18, −0.86, respectively), but was maintained at pre‐intervention levels in LCHF. HCHO and PCHO groups improved times for 10 km race walk: 6.6% (90% CI: 4.1, 9.1%) and 5.3% (3.4, 7.2%), with no improvement (−1.6% (−8.5, 5.3%)) for the LCHF group. In contrast to training with diets providing chronic or periodised high‐CHO availability, and despite a significant improvement in V̇O2 peak , adaptation to the topical LCHF diet negated performance benefits in elite endurance athletes, in part due to reduced exercise economy.
Key points
Three weeks of intensified training and mild energy deficit in elite race walkers increases peak aerobic capacity independent of dietary support.
Adaptation to a ketogenic low carbohydrate, high fat (LCHF) diet markedly increases rates of whole‐body fat oxidation during exercise in race walkers over a range of exercise intensities.
The increased rates of fat oxidation result in reduced economy (increased oxygen demand for a given speed) at velocities that translate to real‐life race performance in elite race walkers.
In contrast to training with diets providing chronic or periodised high carbohydrate availability, adaptation to an LCHF diet impairs performance in elite endurance athletes despite a significant improvement in peak aerobic capacity.
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