Functional food for exercise performance: fact or foe?

Compact food bar improves cardiopulmonary function in men military athletes: A randomized, placebo-controlled, single-blind clinical trial

BACKGROUND

This study aimed to evaluate the effects of compact food bar (CFB) designed on cardiopulmonary function in men athletes who serve in military service.

MATERIALS AND METHODS

In this randomized, single-blind, controlled clinical trial, 46 men of military staff were arranged into 2 groups and studied for 28 days; one branch used 3 packs daily, 700 kcal each, of CFB with Functional compounds (Caffeine and L-arginine) and the other group used regular food during training course. Maximal oxygen uptake (VO₂ Max) in vitro with cardiopulmonary exercise test, body composition, and physical activity were assessed and recorded at baseline and end of the study period.

RESULTS

VO₂ Max (P = 0.05) significantly increased in CFB group compared with baseline. Moreover, VO₂ Max (P = 0.01), VO₂/HR (P = 0.04), oxygen uptake/heart rate (VO₂/HR) (P = 0.03), and ventilation per minute/oxygen uptake (VE/VO₂) (P = 0.03) significantly increased in CFB group compared with control group. In comparison, there was no significant difference in mean ventilation per minute/carbon dioxide production (VE/VCO₂) (P = 0.41), ventilation per minute (VE) (P = 0.69), and breathing frequency (P = 0.056). No significant effect of CFB was found on weight, body mass index (P = 0.23), lean body mass (P = 0.91), and body fat mass (P = 0.91).

CONCLUSION

Our results show that intervention with CFB is more effective than regular diet in improving cardiopulmonary function in men athletes who serve in military service.

Effects of daily ingestion of sodium bicarbonate on acid-base status and anaerobic performance during an altitude sojourn at high altitude: a randomized controlled trial

Background

The present study investigated the effects of chronic sodium bicarbonate (NaHCO₃) ingestion on a single bout of high-intensity exercise and on acid-base balance during 7-day high-altitude exposure.

Methods

Ten recreationally active subjects participated in a pre-test at sea level and a 7-day hiking tour in the Swiss Alps up to 4554 m above sea level. Subjects received either a daily dose of 0.3 g/kg NaHCO₃ solution (n = 5) or water as a placebo (n = 5) for 7 days. Anaerobic high-intensity exercise performance was assessed using the portable tethered sprint running (PTSR) test under normoxic and hypoxic conditions (3585 m). PTSR tests assessed overall peak force, mean force, and fatigue index. Blood lactate levels and blood gas parameters were assessed pre- and post-PTSR. Urinary pH and blood gas parameters were further analyzed daily at rest in early morning samples under normoxic and hypoxic conditions.

Results

There were no significant differences between the bicarbonate and control group in any of the PTSR-related parameters. However, urinary pH (p = 0.003, ηp² = 0.458), early morning blood bicarbonate concentration (p < 0.001, ηp² = 0.457) and base excess (p = 0.002, ηp² = 0.436) were significantly higher in the bicarbonate group compared with the control group under hypoxic conditions.

Conclusions

These results indicate that oral NaHCO₃ ingestion does not ameliorate the hypoxia-induced impairment in anaerobic, high-intensity exercise performance, represented by PTSR-related test parameters, under hypobaric, hypoxic conditions, but the maximal performance measurements may have been negatively affected by other factors, such as poor implementation of PTSR test instructions, pre-acclimatization, the time course of hypoxia-induced renal [HCO₃⁻] compensation, changes in the concentrations of intra- and extracellular ions others than [H⁺] and [HCO₃⁻], or gastrointestinal disturbances caused by NaHCO₃ ingestion. However, chronic NaHCO₃ ingestion improves blood bicarbonate concentration and base excess at altitude, which partially represent the blood buffering capacity.

Enhanced 400-m sprint performance in moderately trained participants by a 4-day alkalizing diet: a counterbalanced, randomized controlled trial

Background

Sodium bicarbonate (NaHCO₃) is an alkalizing agent and its ingestion is used to improve anaerobic performance. However, the influence of alkalizing nutrients on anaerobic exercise performance remains unclear. Therefore, the present study investigated the influence of an alkalizing versus acidizing diet on 400-m sprint performance, blood lactate, blood gas parameters, and urinary pH in moderately trained adults.

Methods

In a randomized crossover design, eleven recreationally active participants (8 men, 3 women) aged 26.0 ± 1.7 years performed one trial under each individual’s unmodified diet and subsequently two trials following either 4 days of an alkalizing (BASE) or acidizing (ACID) diet. Trials consisted of 400-m runs at intervals of 1 week on a tartan track in a randomized order.

Results

We found a significantly lower 400-m performance time for the BASE trial (65.8 ± 7.2 s) compared with the ACID trial (67.3 ± 7.1 s; p = 0.026). In addition, responses were significantly higher following the BASE diet for blood lactate (BASE: 16.3 ± 2.7; ACID: 14.4 ± 2.1 mmol/L; p = 0.32) and urinary pH (BASE: 7.0 ± 0.7; ACID: 5.5 ± 0.7; p = 0.001).

Conclusions

We conclude that a short-term alkalizing diet may improve 400-m performance time in moderately trained participants. Additionally, we found higher blood lactate concentrations under the alkalizing diet, suggesting an enhanced blood or muscle buffer capacity. Thus, an alkalizing diet may be an easy and natural way to enhance 400-m sprint performance for athletes without the necessity of taking artificial dietary supplements.

Ergogenic effect of a traditional natural powder: ghavoot

Ghavoot is a traditional natural energizer in Iran. It is a mixture of different plant seeds that is traditionally used for its energogenic, analgesic, anti-inflammatory, and anti-anxiety properties. Nevertheless, its ergogenic effect has never been studied. Twenty two healthy male students were randomly assigned to the experimental (n = 11) and control (n = 11) groups. Participants in the experimental group received ghavoot (34 g/dl) dissolved in 400 ml milk and the control group received 400 ml milk after 8 hr of fasting at 8 am on three days. Pretest measurements were taken one day before the supplementation and posttest carried out 1 hr after the last drink. The participants performed handgrip force, standing vertical jump, pull-up test, and 60-m speed tests. ANCOVA was carried out to find any differences between the two groups. In the experimental group, we found significant improvements in the handgrip force (p < 0.01), vertical jump (p < 0.001), pull-up test (p < 0.001), and 60-m speed test (p < 0.001). The effects of caffeine, antioxidants, and unsaturated fatty acids were previously investigated, but no supporting evidence is in accordance with our findings to prove the ergogenic effect of each component. However, the synergistic effect of the natural chemicals is expected to be responsible.

Consumption patterns of sweetened food and drink products in a Catholic Middle Eastern Canadian community

OBJECTIVE

The present study describes the consumption patterns of sweetened food and drink products in a Catholic Middle Eastern Canadian community and examines its associations with physical activity, sedentary behaviours and BMI.

DESIGN

A two-stage cross-sectional design was used. In Stage 1 (n 42), 24 h recalls enabled the identification of sweetened products. In Stage 2 (n 192), an FFQ was administered to measure the daily consumption of these products and to collect sociodemographic and behavioural data. Sweetened products were defined as processed culinary ingredients and ultra-processed products for which total sugar content exceeded 20% of total energy.

SETTING

Three Catholic Middle Eastern churches located in Montreal, Canada.

SUBJECTS

Normoglycaemic men and women (18-60 years old).

RESULTS

Twenty-six sweetened products represented an average consumption of 75·4 g total sugars/d or 15·1% of daily energy intake (n 190, 56% women). Soft drinks, juices, sweetened coffee, chocolate, cookies, cakes and muffins were the main sources of consumption and mostly consumed between meals. Age (exp (β) = 0·99; P < 0·01), physical activity (exp (β) = 1·08; P < 0·01) and recreational computer use (exp (β) = 1·17; P < 0·01) were independently associated with sweetened product consumption. The association between sweetened product consumption and physical activity was U-shaped. BMI was not significantly associated with sweetened product consumption but all participants regardless of BMI were above the WHO recommendation for free sugars.

CONCLUSIONS

Being physically active and spending less time using a computer may favour a reduced consumption of sweetened products. Very active individuals may, however, overconsume such products.

Adverse effects of excessive leucine intake depend on dietary protein intake: a transcriptomic analysis to identify useful biomarkers

The present study was conducted to identify reliable gene biomarkers for the adverse effects of excessive leucine (Leu) in Sprague-Dawley rats by DNA microarray. It has long been known that the adverse effects of excessive amino acid intake depend on dietary protein levels. Male rats were divided into 12 groups (n=6) and fed for 1 wk a diet containing low (6%), moderate (12%) or high (40%) protein. Different levels of Leu (0, 2, 4, and 8%) were added to the diets. Consumption of diets containing more than 4% Leu in 6% protein resulted in growth retardation and reduced liver weight, whereas the administration of the same dose of Leu with 12% or 40% protein did not affect them. By a process of systematic data extraction, 6 candidate gene markers were identified. The liver gene expression data obtained from another experiment with 0, 2, 3, 4, and 8% Leu in a low-protein diet was used to examine the validity of these biomarker candidates with receiver operating characteristic (ROC) curve analysis. All of AUC values of the biomarker candidates were more than 0.700, suggesting the effectiveness of the marker candidates as the indices of Leu excess. The cut-off value for the ROC curve of the gene-marker panel, which was obtained by multiple regression analysis of gene markers, indicated that Leu levels higher than 3% have adverse effects. In conclusion, the gene-marker panel suggested that for male rats dietary Leu supplementation of 2% is the NOAEL dose in low-protein (6%) diets.

Sports drinks and energy drinks for children and adolescents: are they appropriate?

Sports and energy drinks are being marketed to children and adolescents for a wide variety of inappropriate uses. Sports drinks and energy drinks are significantly different products, and the terms should not be used interchangeably. The primary objectives of this clinical report are to define the ingredients of sports and energy drinks, categorize the similarities and differences between the products, and discuss misuses and abuses. Secondary objectives are to encourage screening during annual physical examinations for sports and energy drink use, to understand the reasons why youth consumption is widespread, and to improve education aimed at decreasing or eliminating the inappropriate use of these beverages by children and adolescents. Rigorous review and analysis of the literature reveal that caffeine and other stimulant substances contained in energy drinks have no place in the diet of children and adolescents. Furthermore, frequent or excessive intake of caloric sports drinks can substantially increase the risk for overweight or obesity in children and adolescents. Discussion regarding the appropriate use of sports drinks in the youth athlete who participates regularly in endurance or high-intensity sports and vigorous physical activity is beyond the scope of this report.