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1.
Abstract

There is a paucity of dietary data in football referees. In this study, 23 elite main and assistant referees (34.4 ± 5.6 years) completed a 7-day dietary record during the competitive season. No nutritional intake differences were observed between main and assistant referees. Referees’ mean daily energy intake (DEI) was 2819 ± 279 kcal. The intake of proteins (1.7 ± 0.2 g · kg?1), carbohydrates (4.1 ± 0.8 g · kg?1) and fats (1.4 ± 0.2 g · kg?1) represented, respectively, 18.4 ± 1.5%, 44.4 ± 4.4% and 34.6 ± 4.1% of the DEI. Carbohydrate intakes before, during and after exercise were 66 ± 42, 7 ± 15 and 120 ± 62 g. Daily carbohydrate, fibre, polyunsaturated fat and water intakes were below recommendations, while fat, saturated fat, cholesterol and sodium intakes were above recommended values. The prevalence of inadequate intake was high for vitamin E (96%), folate (74%), vitamin A (61%), vitamin C (39%), magnesium (26%) and calcium (22%). Carbohydrate intake before, during and after exercise were far from achieving the minimum recommended values. Most referees demonstrated a negligent behaviour of hydration during exercise. Referees would benefit from dietary education in order to optimise performance and health.  相似文献   

2.
The main determinants of an athlete's protein needs are their training regime and habitual nutrient intake. Most athletes ingest sufficient protein in their habitual diet. Additional protein will confer only a minimal, albeit arguably important, additional advantage. Given sufficient energy intake, lean body mass can be maintained within a wide range of protein intakes. Since there is limited evidence for harmful effects of a high protein intake and there is a metabolic rationale for the efficacy of an increase in protein, if muscle hypertrophy is the goal, a higher protein intake within the context of an athlete's overall dietary requirements may be beneficial. However, there are few convincing outcome data to indicate that the ingestion of a high amount of protein (2–3?g?·?kg?1 BW?·?day?1, where BW?=?body weight) is necessary. Current literature suggests that it may be too simplistic to rely on recommendations of a particular amount of protein per day. Acute studies suggest that for any given amount of protein, the metabolic response is dependent on other factors, including the timing of ingestion in relation to exercise and/or other nutrients, the composition of ingested amino acids and the type of protein.  相似文献   

3.
Low energy availability, defined as low caloric intake relative to exercise energy expenditure, has been linked to endocrine alterations frequently observed in chronically energy-deficient exercising women. Our goal was to determine the endocrine effects of low energy availability in exercising men. Six exercising men (VO2peak: 49.3 ± 2.4 ml · kg?1 · min?1) underwent two conditions of low energy availability (15 kcal · kg?1 fat-free mass [FFM] · day?1) and two energy-balanced conditions (40 kcal · kg?1 FFM · day?1) in randomised order. During one low energy availability and one balanced condition, participants exercised to expend 15 kcal · kg?1 FFM · day?1; no exercise was conducted during the other two conditions. Metabolic hormones were assessed before and after each 4-day period. Following both low energy availability conditions, leptin (?53% to ?56%) and insulin (?34% to ?38%) were reduced (P < 0.05). Reductions in leptin and insulin were independent of whether low energy availability was attained with or without exercise (P > 0.80). Low energy availability did not significantly impact ghrelin, triiodothyronine, testosterone and IGF-1 (all P > 0.05). The observed reductions in leptin and insulin were in the same magnitude as changes previously reported in sedentary women. Further research is needed to understand why other metabolic hormones are more robust against low energy availability in exercising men than those in sedentary and exercising women.  相似文献   

4.
Abstract

Several nutritional strategies can optimize muscle bulk and strength adaptations and enhance recovery from heavy training sessions. Adequate energy intake to meet the needs of training and carbohydrate intake sufficient to maintain glycogen stores (>7 g carbohydrate·kg?1·day?1 for women; >8 g carbohydrate·kg?1·day?1 for men) are important. Dietary protein intake for top sport athletes should include some foods with high biological value, with a maximum requirement of approximately 1.7 g·kg?1·day?1 being easily met with an energy sufficient diet. The early provision of carbohydrate (>1 g·kg?1) and protein (>10 g) early after an exercise session will enhance protein balance and optimize glycogen repletion. Creatine monohydrate supplementation over several days increases body mass through water retention and can increase high-intensity repetitive ergometer performance. Creatine supplementation can enhance total body and lean fat free mass gains during resistance exercise training; however, strength gains do not appear to be enhanced versus an optimal nutritional strategy (immediate post-exercise protein and carbohydrate). Some studies have suggested that β-OH-methyl butyric acid (β-HMB) can enhance gains made through resistance exercise training; however, it has not been compared “head to head” with optimal nutritional practices. Overall, the most effective way to increase strength and bulk is to perform sport-specific resistance exercise training with the provision of adequate energy, carbohydrate, and protein. Creatine monohydrate and β-HMB supplementation may enhance the strength gains made through training by a small margin but the trade-off is likely to be greater bulk, which may be ergolytic for any athlete participating in a weight-supported activity.  相似文献   

5.
Dietary intake, vitamin status and oxidative stress were evaluated in 17 elite male boxers. Ten of them frequently reduced body weight rapidly before competitions (Weight Loss Group) and 7 did not practice rapid weight loss (Control Group). Food record checklists, blood samples for determination of vitamin status and plasma glutathione levels were obtained during a week of weight maintenance, a pre-competition week and a post-competition week. The average dietary intakes in both groups were 33 ± 8 kcal·kg?1, 3.7 ± 1.1 g·kg?1 carbohydrates, 1.5 ± 0.4 g·kg?1 protein, 1.2 ± 0.4 g·kg?1 fat and 2.2 ± 1.0 L water per day (excluding pre-competition week in Weight Loss Group). Energy (18 ± 7 kcal·kg?1), carbohydrate (2.2 ± 0.8 g·kg?1), protein (0.8 ± 0.4 g·kg?1), fat (0.6 ± 0.3 g·kg?1) and water (1.6 ± 0.6 L) consumption (P-values <0.001) and intakes of most vitamins (P-values < 0.05) were significantly reduced during the pre-competition week in the Weight Loss Group. In both groups, the intakes of vitamins A, E and folate were below recommended values throughout the three periods; however, blood vitamin and plasma glutathione levels did not change significantly. Our findings indicate a low-caloric and low-carbohydrate diet in elite boxers, regardless of participating in rapid weight loss or not. Apparently, the pre-competitional malnutitrition in the Weight Loss Group did not induce alterations in the vitamin and glutathione status.  相似文献   

6.
ABSTRACT

Ultra-endurance athletes accumulate an energy deficit throughout their events and those competing in self-sufficient multi-stage races are particularly vulnerable due to load carriage considerations. Whilst urinary ketones have previously been noted in ultra-endurance exercise and attributed to insufficient carbohydrate (CHO) availability, not all studies have reported concomitant CHO intake. Our aim was to determine changes in blood glucose and β-hydroxybutyrate concentrations over five days (240 km) of a self-sufficient multi-stage ultramarathon in combination with quantification of energy and macronutrient intakes, estimated energy expenditure and evaluation of energy balance. Thirteen runners (8 male, 5 female, mean age 40 ± 8 years) participated in the study. Glucose and β-hydroxybutyrate were measured every day immediately post-running, and food diaries completed daily. CHO intakes of 301 ± 106 g·day?1 (4.3 ± 1.8 g·kg?1·day?1) were not sufficient to avoid ketosis (5-day mean β-hydroxybutyrate: 1.1 ± 0.6 mmol.L?1). Furthermore, ketosis was not attenuated even when CHO intake was high (9 g·kg?1·day?1). This suggests that competing in a state of ketosis may be inevitable during multi-stage events where load reduction is prioritised over energy provisions. Attenuating negative impacts associated with such a metabolic shift in athletes unaccustomed to CHO and energy restriction requires further exploration.  相似文献   

7.
Carbohydrate (CHO) availability during endurance exercise seems to attenuate exercise-induced perturbations of cellular homeostasis and might consequently diminish the stimulus for training adaptation. Therefore, a negative effect of CHO intake on endurance training efficacy seems plausible. This study aimed to test the influence of carbohydrate intake on the efficacy of an endurance training program on previously untrained healthy adults. A randomized cross-over trial (8-week wash-out period) was conducted in 23 men and women with two 8-week training periods (with vs. without intake of 50g glucose before each training bout). Training intervention consisted of 4x45 min running/walking sessions/week at 70% of heart rate reserve. Exhaustive, ramp-shaped exercise tests with gas exchange measurements were conducted before and after each training period. Outcome measures were maximum oxygen uptake (VO2max) and ventilatory anaerobic threshold (VT). VO2max and VT increased after training regardless of CHO intake (VO2max: Non-CHO 2.6 ± 3.0 ml*min?1*kg?1 p = 0.004; CHO 1.4 ± 2.5 ml*min?1*kg?1 p = 0.049; VT: Non-CHO 4.2 ± 4.2 ml*min?1*kg?1 p < 0.001; CHO 3.0 ± 4.2 ml*min?1*kg?1 p = 0.003). The 95% confidence interval (CI) for the difference between conditions was between +0.1 and +2.1 ml*min?1*kg?1 for VO2max and between ?1.2 and +3.1 for VT. It is concluded that carbohydrate intake could potentially impair the efficacy of an endurance training program.  相似文献   

8.
Abstract

Maternal dietary habits influence maternal and foetal health, representing a pathway for intervention to maximise pregnancy outcomes. Advice on energy intake is provided on a trimester basis, with no additional calories required in the first trimester and an additional 340?kcal?d?1 and 452?kcal?d?1 needed for the second and third trimesters. Energy intake depends on pre-gravid body mass index (BMI); underweight women are recommended an increase of 150, 200 and 300?kcal?d?1 during the first, second and third trimester, normal weight women an increase of 0, 350 and 500?kcal?d?1 and obese women an increase of 0, 450 and 350?kcal?day?1. The recommendations for carbohydrate and protein intake are 175?g?d?1 and 0.88–1.1?g?kgBM?d?1, with no change to fat intake. The number of pre-gravid obese women is rising; therefore, we need to regulate weight in women of childbearing age and limit gestational weight gain to within the recommended ranges [overweight women 6.8–11.3?kg and obese women 5.0–9.1?kg]. This can be achieved using nutritional interventions, as dietary changes have been shown to help with gestational weight management. As pregnancy has been identified as a risk factor for the development of obesity, normal weight women should gain 11.5–16.0?kg during pregnancy. While some research has shown that dietary interventions help to regulate gestational weight gain and promote postpartum weight loss to some extent, future research is needed to provide safe and effective guidelines to maximise these effects, while benefitting maternal and foetal health.  相似文献   

9.
Abstract

The purpose of this study was to examine macronutrient intake, energy density and energy intake distribution that may be associated with low energy availability (EA) in Division I female soccer players. The energy intake, exercise energy expenditure and EA of 19 participants (18–21 years) was assessed during the pre-, mid- and postseasons. Repeated measures analysis of variance was performed to examine the changes across the season. Chi-square analysis was performed to examine the distribution of participants meeting the American College of Sports Medicine recommendations for carbohydrate and protein consumption. Independent t-tests were used to compare differences between groups. The proportion of athletes who did not meet the American College of Sports Medicine recommendations for carbohydrate intake (6–10 g . kg–1 BW) was significantly greater in the low (<30 kcal . kg–1 LBM) than higher (≥30 kcal . kg–1 LBM) EA group (χ2 (1) = 7.5; P = 0.006). Participants with low compared to higher EA consumed a lower energy dense dinner (0.8 ± 0.1 vs. 1.4 ± 0.1 kcal . g–1; P = 0.004) after a soccer match during midseason. No differences in the percentage (%) of kilocalories from food (84.5 ± 2.0% vs. 84.7 ± 2.6%), sports drinks (7.3 ± 1.4% vs. 6.0 ± 3.2%), other drinks (7.6 ± 1.5 % vs. 6.0 ± 1.5%) or bars/gels/beans (1.7 ± 0.6 vs. 3.0 ± 1.5) were observed in participants with low compared to higher EA (P > 0.05) during the pre- and midseasons. Identifying inadequate carbohydrate intake and the practice of consuming lower energy dense meals may be important in preventing low EA conditions and consequently the Female Athlete Triad.  相似文献   

10.
Strenuous bouts of prolonged exercise and heavy training are associated with depressed immune cell function. Furthermore, inadequate or inappropriate nutrition can compound the negative influence of heavy exertion on immunocompetence. Dietary deficiencies of protein and specific micronutrients have long been associated with immune dysfunction. An adequate intake of iron, zinc and vitamins A, E, B6 and B12 is particularly important for the maintenance of immune function, but excess intakes of some micronutrients can also impair immune function and have other adverse effects on health. Immune system depression has also been associated with an excess intake of fat. To maintain immune function, athletes should eat a well-balanced diet sufficient to meet their energy requirements. An athlete exercising in a carbohydrate-depleted state experiences larger increases in circulating stress hormones and a greater perturbation of several immune function indices. Conversely, consuming 30–60?g carbohydrate?·?h?1 during sustained intensive exercise attenuates rises in stress hormones such as cortisol and appears to limit the degree of exercise-induced immune depression. Convincing evidence that so-called ‘immune-boosting’ supplements, including high doses of antioxidant vitamins, glutamine, zinc, probiotics and Echinacea, prevent exercise-induced immune impairment is currently lacking.  相似文献   

11.
Acute ingestion of ketone salts induces nutritional ketosis by elevating β-hydroxybutyrate (βHB), but few studies have examined the metabolic effects of ingestion prior to exercise. Nineteen trained cyclists (12 male, 7 female) undertook graded exercise (8 min each at ～30%, 40%, 50%, 60%, 70%, and 80% VO2peak) on a cycle ergometer on two occasions separated by either 7 or 14 days. Trials included ingestion of boluses of either (i) plain water (3.8?mL?kg?body mass?1) (CON) or (ii) βHB salts (0.38?g?kg?body mass?1) in plain water (3.8?mL?kg body mass?1) (KET), at both 60 min and 15 min prior to exercise. During KET, plasma [βHB] increased to 0.33?±?0.16?mM prior to exercise and 0.44?±?0.15?mM at the end of exercise (both p?.05). Plasma glucose was 0.44?±?0.27?mM lower (p?.01) 30?min after ingestion of KET and remained ～0.2?mM lower throughout exercise compared to CON (p?.001). Respiratory exchange ratio (RER) was higher during KET compared to CON (p?.001) and 0.03–0.04 higher from 30%VO2peak to 60%VO2peak (all p?.05). No differences in plasma lactate, rate of perceived exertion, or gross or delta efficiency were observed between trials. Gastrointestinal symptoms were reported in 13 out of 19 participants during KET. Acute ingestion of βHB salts induces nutritional ketosis and alters the metabolic response to exercise in trained cyclists. Elevated RER during KET may be indicative of increased ketone body oxidation during exercise, but at the plasma βHB concentrations achieved, ingestion of βHB salts does not affect lactate appearance, perceived exertion, or muscular efficiency.  相似文献   

12.
This study investigated the effect of a single session of resistance exercise on postprandial lipaemia. Eleven healthy normolipidaemic men with a mean age of 23 (standard error = 1.4) years performed two trials at least 1 week apart in a counterbalanced randomized design. In each trial, participants consumed a test meal (1.2?g fat, 1.1?g carbohydrate, 0.2?g protein and 68 kJ?·?kg?1 body mass) between 08.00 and 09.00?h following a 12?h fast. The afternoon before one trial, the participants performed an 88?min bout of resistance exercise. Before the other trial, the participants were inactive (control trial). Resistance exercise was performed using free weights and included four sets of 10 repetitions of each of 11 exercises. Sets were performed at 80% of 10-repetition maximum with a 2?min work and rest interval. Venous blood samples were obtained in the fasted state and at intervals for 6?h postprandially. Fasting plasma triacylglycerol (TAG) concentration did not differ significantly between control (1.03?±?0.13?mmol?·?l?1) and exercise (0.94?±?0.09?mmol?·?l?1) trials (mean?± standard error). Similarly, the 6?h total area under the plasma TAG concentration versus time curve did not differ significantly between the control (9.84?±?1.40?mmol?·?l?1?·?6?h?1) and exercise (9.38?±?1.12?mmol?·?l?1?·?6?h?1) trials. These findings suggest that a single session of resistance exercise does not reduce postprandial lipaemia.  相似文献   

13.
ABSTRACT

For the first time we aimed to: (1) assess fat-free mass (FFM) and RMR in youth soccer players, (2) compare measured RMR to estimated RMR using previously published prediction equations, and (3) develop a novel population-specific prediction equation. In a cross-sectional design, 99 males from a Premier League academy underwent assessments of body composition (DXA) and RMR (indirect-calorimetry). Measured RMR was compared to estimated values from five prediction equations. A novel RMR prediction equation was developed using stepwise multiple regression. FFM increased (P<0.05) between U12 (31.6±4.2 kg) and U16 (56.3±5.3 kg) after which no further increases occurred (P>0.05). RMR in the U12s (1655±195 kcal.day?1), U13s (1720±205 kcal.day?1) and U14s (1846±218kcal.day?1) was significantly lower than the U15s (1957±128 kcal.day?1), U16s (2042±155 kcal.day?1), U18s (1875±180 kcal.day?1) and U23s (1941±197 kcal.day?1) squads (P>0.05). FFM was the single best predictor of RMR (r2=0.43; P<0.01) and was subsequently included in the novel prediction equation: RMR (kcal.day?1) = 1315 + (11.1 x FFM in kg). Both FFM and RMR increase from 12-16 years old, thus highlighting the requirement to adjust daily energy intake to support growth and maturation. The novel prediction RMR equation developed may help to inform daily energy requirements.  相似文献   

14.
ABSTRACT

Prior exercise can negatively affect movement economy of a subsequent task. However, the impact of cycling exercise on the energy cost of subsequent running is difficult to ascertain, possibly because of the use of different methods of calculating economy. We examined the influence of a simulated cycling bout on running physiological cost (running economy, heart rate and ventilation rates) and perceptual responses (ratings of perceived exertion and effort) by comparing two running bouts, performed before and after cycling using different running economy calculation methods. Seventeen competitive male triathletes ran at race pace before and after a simulated Olympic-distance cycling bout. Running economy was calculated as V?O2 (mL?kg?1?min?1), oxygen cost (EO2, mL?kg?1?m?1) and aerobic energy cost (Eaer, J?kg?1?m?1). All measures of running economy and perceptual responses indicated significant alterations imposed by prior cycling. Despite a good level of agreement with minimal bias between calculation methods, differences (p < 0.05) were observed between Eaer and both V?O2 and EO2. The results confirmed that prior cycling increased physiological cost and perceptual responses in a subsequent running bout. It is recommended that Eaer be calculated as a more valid measure of running economy alongside perceptual responses to assist in the identification of individual responses in running economy following cycling.  相似文献   

15.
Physical inactivity is a major contributor to low-grade systemic inflammation. Most of the studies characterizing interleukin-6 (IL-6) and tumour necrosis factor-α (TNF-α) release from exercising legs have been done in young, healthy men, but studies on inactivity in older people are lacking. The impact of 14 days of one-leg immobilization (IM) on IL-6 and TNF-α release during exercise in comparison to the contralateral control (CON) leg was investigated. Fifteen healthy men (age 68.1?±?1.1?year (mean?±?SEM); BMI 27.0?±?0.4 kg·m2; VO2max 33.3?±?1.6 ml·kg?1·min?1) performed 45?min of two-leg dynamic knee extensor exercise at 19.5?±?0.9 W. Arterial and femoral venous blood samples from the CON and the IM legs were collected every 15?min during exercise, and thigh blood flow was measured with ultrasound Doppler. Arterial plasma IL-6 concentration increased with exercise (rest vs. 45?min, main effect p?p?p?=?.085, effect size 0.28) higher in the IM leg compared to the CON leg (288 (95% CI: 213–373) vs. 220 (95% CI: 152–299) pg·min?1, respectively). There was no release of TNF-α in either leg and arterial concentrations remained unchanged during exercise (p?>?.05). In conclusion, exercise induces more pronounced IL-6 secretion in healthy older men. Two weeks of unilateral immobilization on the other hand had only a minor influence on IL-6 release. Neither immobilization nor exercise had an effect on TNF-α release across the working legs in older men.  相似文献   

16.
Abstract

Ingesting carbohydrate plus protein following prolonged exercise may restore exercise capacity more effectively than ingestion of carbohydrate alone. The objective of the present study was to determine whether this potential benefit is a consequence of the protein fraction per se or simply due to the additional energy it provides. Six active males participated in three trials, each involving a 90-min treadmill run at 70% maximal oxygen uptake (run 1) followed by a 4-h recovery. At 30-min intervals during recovery, participants ingested solutions containing: (1) 0.8 g carbohydrate · kg body mass (BM)?1 · h?1 plus 0.3 g · kg?1 · h?1 of whey protein isolate (CHO-PRO); (2) 0.8 g carbohydrate · kg BM?1 · h?1 (CHO); or (3) 1.1 g carbohydrate · kg BM?1 · h?1 (CHO-CHO). The latter two solutions matched the CHO-PRO solution for carbohydrate and for energy, respectively. Following recovery, participants ran to exhaustion at 70% maximal oxygen uptake (run 2). Exercise capacity during run 2 was greater following ingestion of CHO-PRO and CHO-CHO than following ingestion of CHO (P ≤ 0.05) with no significant difference between the CHO-PRO and CHO-CHO treatments. In conclusion, increasing the energy content of these recovery solutions extended run time to exhaustion, irrespective of whether the additional energy originated from sucrose or whey protein isolate.  相似文献   

17.
There is a paucity of studies that have evaluated substrate utilisation and protein catabolism during multiday strenuous exercise in athletes. Eleven well-trained male cyclists completed 3 h of race-simulated cycling on 4 consecutive days. Cyclist exercised 2 h postprandially and with carbohydrate supplementation (~50 g · h?1) during exercise. Whole body substrate utilisation was measured by indirect calorimetry, protein catabolism from sweat and urine urea excretion, and blood metabolite concentration was evaluated. Protein catabolism during exercise was significantly greater on days 2–4 (29.9 ± 8.8; 34.0 ± 11.2; 32.0 ± 7.3 g for days 2, 3, and 4, respectively) compared to day 1 (23.3 ± 7.6 g), P < 0.05. Fat oxidation was greater at 21 km (~45 min) on days 2–4 (1.06 ± 0.23; 1.08 ± 0.25; 1.12 ± 0.29 g · min?1) compared to day 1 (0.74 ± 0.23 g · min?1, P < 0.05), but the rate of carbohydrate and fat oxidation was similar between days at 50 and 80 km. Whole body substrate utilisation is altered on subsequent days of multiday prolonged strenuous cycling that includes a quicker transition to greater fat utilisation from exercise onset and a 28–46% greater reliance on endogenous protein catabolism on all successive days.  相似文献   

18.
Abstract

Excess protein intake can adversely affect the bone via an increase in calcium excretion, while suitable mechanical loading promotes osteogenesis. We therefore investigated whether vibration exposure could alleviate the bone mineral losses associated with a metabolic acidosis. Ten healthy individuals aged 22 – 29 years (median = 25) underwent three 5-day study periods while monitoring their dietary intake. The study consisted of recording the participants' usual dietary intake for 5 consecutive days. Participants were then randomly divided into two groups, one of which received a protein supplement (2 g · kg?1 body mass · day?1; n = 5) and the other whole-body low-magnitude (3.5 g), low-frequency (30 Hz) mechanical vibration (WBV) delivered through a specially designed vibrating plate for 10 min each day (n = 5). Finally, for the third treatment period, all participants consumed the protein supplement added to their normal diet and were exposed to WBV exercise for 10 min per day. Daily urine samples were collected throughout the experimental periods to determine the excretion of calcium, phosphate, titratable acid, urea, and C-telopeptide. As expected, when the participants underwent the high protein intake, there was an increase in urinary excretion rates of calcium (P < 0.001), phosphate (P < 0.003), urea (P < 0.001), titratable acid (P < 0.001), and C-telopeptide (P < 0.05) compared with baseline values. However, high protein intake coupled with vibration stimulation resulted in a significant reduction in urinary calcium (P = 0.006), phosphate excretion (P = 0.021), and C-telopeptide (P < 0.05) compared with protein intake alone, but did not affect titratable acid and urea output. The participants showed no effect of WBV exercise alone on urinary excretion of calcium, phosphate, urea, titratable acid, or C-telopeptide. The results indicate that vibration stimulation can moderate the increase in bone resorption and reduction in bone formation caused by a metabolic acidosis.  相似文献   

19.
Dietary analysis of Academy soccer players highlights that total energy and carbohydrate intakes are less than optimal, especially, on match-days. As UK Academy matches predominantly kick-off at ～11:00?h, breakfast is likely the last pre-exercise meal and thus may provide an intervention opportunity on match-day. Accordingly, the physiological and performance effects of an increased calorie breakfast consumed ～135-min before soccer-specific exercise was investigated. English Premier League Academy soccer players (n?=?7) repeated a 90-min soccer match simulation on two occasions after consumption of habitual (Bhab; ～1100?kJ) or increased (Binc; ～2100?kJ) energy breakfasts standardised for macronutrient contributions (～60% carbohydrates, ～15% proteins and ～25% fats). Countermovement jump height, sprint velocities (15-m and 30-m), 30-m repeated sprint maintenance, gut fullness, abdominal discomfort and soccer dribbling performances were measured. Blood samples were taken at rest, pre-exercise, half-time and every 15-min during exercise. Although dribbling precision (P?=?.522; 29.9?±?5.5?cm) and success (P?=?.505; 94?±?8%) were unchanged throughout all time-points, mean dribbling speed was faster (4.3?±?5.7%) in Binc relative to Bhab (P?=?.023; 2.84 vs 2.75?m?s?1). Greater feelings of gut fullness (67?±?17%, P?=?.001) were observed in Binc without changes in abdominal discomfort (P?=?.595). All other physical performance measures and blood lactate and glucose concentrations were comparable between trials (all P?>?.05). Findings demonstrate that Academy soccer players were able to increase pre-match energy intake without experiencing abdominal discomfort; thus, likely contributing to the amelioration of energy deficits on match-days. Furthermore, whilst Binc produced limited benefits to physical performance, increased dribbling speed was identified, which may be of benefit to match-play.  相似文献   

20.
This study compares test-retest reliability and peak exercise responses from ramp-incremented (RAMP) and maximal perceptually-regulated (PRETmax) exercise tests during arm crank exercise in individuals reliant on manual wheelchair propulsion (MWP). Ten untrained participants completed four trials over 2-weeks (two RAMP (0–40 W + 5–10 W · min?1) trials and two PRETmax. PRETmax consisted of five, 2-min stages performed at Ratings of Perceived Exertion (RPE) 11, 13, 15, 17 and 20). Participants freely changed the power output to match the required RPE. Gas exchange variables, heart rate, power output, RPE and affect were determined throughout trials. The V?O2peak from RAMP (14.8 ± 5.5 ml · kg?1 · min?1) and PRETmax (13.9 ± 5.2 ml · kg?1 · min?1) trials were not different (P = 0.08). Measurement error was 1.7 and 2.2 ml · kg?1 · min?1 and coefficient of variation 5.9% and 8.1% for measuring V?O2peak from RAMP and PRETmax, respectively. Affect was more positive at RPE 13 (P = 0.02), 15 (P = 0.01) and 17 (P = 0.01) during PRETmax. Findings suggest that PRETmax can be used to measure V?O2peak in participants reliant on MWP and leads to a more positive affective response compared to RAMP.  相似文献   

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