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Workers spend a large amount of time working, limiting the possibility of meeting physical activity (PA) guidelines. A better health-related quality of life (HRQoL) provides benefits for the employee and company. The aim of this study was to analyse the associations of four behavioural categories between compliance with PA guidelines (aerobic and strength training) and sedentary time with workers’ HRQoL. We classified the sample into four categories: (1) “Physically active & low sedentary”, (2) “Physically active & high sedentary”, (3) “Physically inactive & low sedentary”, and (4) “Physically inactive & high sedentary”. Student’s t-tests for two independent samples and a multiple linear regression adjusted for covariates were performed. A total of 1004 employees of the multinational company Grupo Red Eléctrica participated. Compliance with PA guidelines and a low level of sedentarism were associated with higher HRQoL (p < 0.001). Compared to “physically inactive & high sedentary”, “physically active & low sedentary” and “physically active & high sedentary” workers obtained a better HRQoL (B = 5.47; p = 0.006 and B = 4.10; p = 0.003; respectively). In this sample of Spanish workers, being physically active was associated with a better HRQoL, even in those with high sedentary time. Experimental studies are needed to confirm our results.

The effects of caffeine were investigated in judo, boxing, taekwondo and Brazilian jiu-jitsu. However, this substance was never investigated regarding traditional jiu-jitsu. Therefore, the aim of this research was to analyze the effects of caffeine in the Special Judo Fitness Test (SJFT) and technical variables during combat in traditional jiu-jitsu elite athletes. Methods: Twenty-two young professionals of traditional jiu-jitsu, 11 men and 11 women (age = 22 ± 4 (18–33) years, body mass = 66.6 ± 10.8 (46.2–86.1) kg, height = 1.70 ± 0.9 (1.55–1.85) m) with 15 ± 7 years of experience in traditional jiu-jitsu, participated in a double-blind, counterbalanced, crossover study. In two different conditions, the traditional jiu-jitsu athletes ingested 3 mg/kg body mass of caffeine or a placebo. After 60 min, they performed the SJFT test to measure throwing performance, and subsequently, combat to analyze offensive and defensive hitting techniques. Results: Caffeine had a main effect on the number of throws during the SJFT test (P < 0.01). In addition, it was effective in sets 2 (13 ± 2 vs. 14 ± 2; p = 0.01) and 3 (12 ± 2 vs. 13 ± 1; p = 0.03). There was also a main effect during the test on heart rate when caffeine was ingested (F = 12.48, p < 0.01). The effects of caffeine were similar compared to the placebo condition regarding performance during combat both in offensive and defensive fighting variables Conclusions: the pre-exercise ingestion of 3 mg/kg body mass of caffeine increased performance in the SJFT test, decreased fatigue perception, and increased power and endurance perception in professionally traditional jiu-jitsu athletes. However, it did not seem to improve offensive and defensive technical actions during combat.

The attainment of high inter-day reliability is crucial to determine changes in resting metabolic rate (RMR), respiratory exchange ratio (RER), maximal fat oxidation during exercise (MFO) and the intensity that elicits MFO (Fatmax) after an intervention. This study aimed to analyze the inter-day reliability of RMR, RER, MFO and Fatmax in healthy adults using the Ergostik gas analyzer. Fourteen healthy men (age: 24.4 ± 5.0 years, maximum oxygen uptake (VO2max): 47.5 ± 11.9 mL/kg/min) participated in a repeated-measures study. The study consisted of two identical experimental trials (Day 1 and Day 2) in which the participants underwent an indirect calorimetry assessment at resting and during an incremental exercise test. Stoichiometric equations were used to calculate energy expenditure and substrate oxidation rates. There were no significant differences when comparing RMR (1999.3 ± 273.9 vs. 1955.7 ± 362.6 kcal/day, p = 0.389), RER (0.87 ± 0.05 vs. 0.89 ± 0.05, p = 0.143), MFO (0.32 ± 0.20 vs. 0.31 ± 0.20 g/min, p = 0.776) and Fatmax (45.0 ± 8.6 vs. 46.4 ± 8.4% VO2max, p = 0.435) values in Day 1 vs. Day 2. The inter-day coefficient of variation for RMR, RER, MFO and Fatmax were 4.85 ± 5.48%, 3.22 ± 3.14%, 7.78 ± 5.51%, and 6.51 ± 8.04%, respectively. In summary, the current results show a good inter-day reliability when RMR, RER, MFO and Fatmax are determined in healthy men using the Ergostik gas analyzer., Francisco de Vitoria University, grant number UFV-18/2020

Aim Oral caffeine intake has been deemed as an effective supplementation strategy to enhance fat oxidation during aerobic exercise with a steady-state intensity. However, in real exercise scenarios, individuals habitually train with autoregulation of exercise intensity. This study aimed to analyze the effect of oral caffeine intake during self-paced cycling on autoregulated exercise intensity and substrate oxidation. Methods Fifteen young and healthy participants (11 men and 4 women) participated in a double-blind, randomized, cross-over investigation. Each participant took part in 2 experimental days consisting of pedaling for 1 h with a self-selected wattage. Participants were told that they had to exercise at a moderate intensity to maximize fat oxidation. On one occasion participants ingested 3 mg/kg of caffeine and on the other occasion ingested a placebo. Energy expenditure, fat oxidation rate, and carbohydrate oxidation rate were continuously measured during exercise by indirect calorimetry. Results In comparison to the placebo, caffeine intake increased the self-selected wattage (on average, 105 ± 44 vs 117 ± 45 W, respectively, P

By using deceptive experiments in which participants are informed that they received caffeine when, in fact, they received an inert substance (i.e., placebo), several investigations have demonstrated that exercise performance can be enhanced to a similar degree as a known caffeine dose. This ‘placebo effect’ phenomenon may be part of the mechanisms explaining caffeine’s ergogenicity in exercise. However, there is no study that has established whether the placebo effect of caffeine is also present for other benefits obtained with acute caffeine intake, such as enhanced fat oxidation during exercise. Therefore, the aim of this investigation was to investigate the placebo effect of caffeine on fat oxidation during exercise. Twelve young men participated in a deceptive double-blind cross-over experiment. Each participant completed three identical trials consisting of a step incremental exercise test from 30 to 80% of V.O2max. In the two first trials, participants ingested either 3 mg/kg of cellulose (placebo) or 3 mg/kg of caffeine (received caffeine) in a randomized order. In the third trial, participants were informed that they had received 3 mg/kg of caffeine, but a placebo was provided (informed caffeine). Fat oxidation rates were derived from stoichiometric equations. In received caffeine, participants increased their rate of fat oxidation over the values obtained with the placebo at 30%, 40%, 50%, and 60% of V.O2max (all p &lt, 0.050). In informed caffeine, participants increased their rate of fat oxidation at 30%, 40%, 50% 60%, and 70% of V.O2max (all p &lt, 0.050) over the placebo, while there were no differences between received versus informed caffeine. In comparison to placebo (0.32 ± 0.15 g/min), the rate of maximal fat oxidation was higher in received caffeine (0.44 ± 0.22 g/min, p = 0.045) and in informed caffeine (0.41 ± 0.20 g/min, p = 0.026) with no differences between received versus informed caffeine. However, the intensity at which maximal fat oxidation rate was obtained (i.e., Fatmax) was similar in placebo, received caffeine, and informed caffeine trials (42.5 ± 4.5, 44.2 ± 9.0, and 41.7 ± 10.5% of V.O2max, respectively, p = 0.539). In conclusion, the expectancy of having received caffeine produced similar effects on fat oxidation rate during exercise than actually receiving caffeine. Therefore, the placebo effect of caffeine is also present for the benefits of acute caffeine intake on substrate oxidation during exercise and it may be used to enhance fat oxidation during exercise in participants while reducing any risks to health that this substance may have.

The p-synephrine is the principal phytochemical found in bitter orange (Citrus aurantium). This substance is widely included in dietary supplements for weight loss/body fat reduction due to its potential benefits of increasing fat oxidation. For years, p-synephrine-containing dietary supplements have been marketed without proper knowledge of their true effectiveness to enhance fat utilization, especially when combined with exercise. However, the effects of p-synephrine on fat oxidation during exercise have been investigated in the last few years. The aim of the current discussion is to summarize the evidence on the effects of p-synephrine intake on fat oxidation and performance during exercise. Previous investigations have demonstrated that the acute intake of p-synephrine does not modify running sprint performance, jumping capacity, or aerobic capacity. However, the acute intake of p-synephrine, in a dose of 2–3 mg/kg of body mass, has been effective to enhance the rate of fat oxidation during incremental and continuous exercise. This effect has been observed in a range of exercise workloads between 30% and 80% of peak oxygen uptake (VO2peak). The p-synephrine has the ability to increase the maximal rate of fat oxidation during exercise of increasing intensity without affecting the workload at which maximal fat oxidation is obtained (Fatmax). The effect of p-synephrine on fat oxidation is normally accompanied by a concomitant reduction of carbohydrate utilization during exercise, without modifying the energy expended during exercise. The shifting in substrate oxidation is obtained without any effect on heart rate during exercise and the prevalence of adverse effects is negligible. Thus, the acute use of p-synephrine, or p-synephrine-containing products, might offer some benefits for those individuals seeking higher fat utilization during exercise at low to moderate intensities. However, more research is still necessary to determine if the effect of p-synephrine on fat oxidation during exercise is maintained with chronic ingestion, in order to ascertain the utility of this substance in conjunction with exercise programs to produce an effective body fat/weight loss reduction.

The p-synephrine is the principal phytochemical found in bitter orange (Citrus aurantium). This substance is widely included in dietary supplements for weight loss/body fat reduction due to its potential benefits of increasing fat oxidation. For years, p-synephrine-containing dietary supplements have been marketed without proper knowledge of their true effectiveness to enhance fat utilization, especially when combined with exercise. However, the effects of p-synephrine on fat oxidation during exercise have been investigated in the last few years. The aim of the current discussion is to summarize the evidence on the effects of p-synephrine intake on fat oxidation and performance during exercise. Previous investigations have demonstrated that the acute intake of p-synephrine does not modify running sprint performance, jumping capacity, or aerobic capacity. However, the acute intake of p-synephrine, in a dose of 2–3 mg/kg of body mass, has been effective to enhance the rate of fat oxidation during incremental and continuous exercise. This effect has been observed in a range of exercise workloads between 30% and 80% of peak oxygen uptake (VO2peak). The p-synephrine has the ability to increase the maximal rate of fat oxidation during exercise of increasing intensity without affecting the workload at which maximal fat oxidation is obtained (Fatmax). The effect of p-synephrine on fat oxidation is normally accompanied by a concomitant reduction of carbohydrate utilization during exercise, without modifying the energy expended during exercise. The shifting in substrate oxidation is obtained without any effect on heart rate during exercise and the prevalence of adverse effects is negligible. Thus, the acute use of p-synephrine, or p-synephrine-containing products, might offer some benefits for those individuals seeking higher fat utilization during exercise at low to moderate intensities. However, more research is still necessary to determine if the effect of p-synephrine on fat oxidation during exercise is maintained with chronic ingestion, in order to ascertain the utility of this substance in conjunction with exercise programs to produce an effective body fat/weight loss reduction.

Aims: In male athletes, caffeine is considered an ergogenic aid to increase anaerobic performance during the Wingate anaerobic test (WANT). However, information about the effect of caffeine on WANT performance in female athletes is contradictory. Furthermore, it is unknown whether the ergogenicity of caffeine is present during all the phases of the menstrual cycle. The aim of this study was to investigate the effects of caffeine intake on WANT performance during 3 phases of the menstrual cycle. Methods: Thirteen well-trained eumenorrhoeic triathletes participated in a double-blind, placebo-controlled, cross-over experimental trial. On 2 different days in each phase, and in randomized order, participants ingested caffeine (3 mg kg−1 ) or a placebo (cellulose). The menstrual cycle phases were individually characterized as follows: (i) early follicular; (ii) preovulatory; and (iii) midluteal. In each trial, participants performed a 15-s adapted version of the WANT. Results: In comparison to the placebo, caffeine increased peak power during the WANT in the early follicular (8.6 ± 0.8 vs 8.9 ± 0.9 W/kg, P = .04; effect size [d] = 0.45), preovulatory (8.6 ± 0.9 vs 8.9 ± 0.9 W/kg, P = .04; d = 0.23) and mid-luteal phases (8.6 ± 0.8 vs 8.9 ± 0.9 W/kg, P < .01; d = 0.52). Conclusion: The ergogenic effect of caffeine on WANT peak cycling power was of a similar magnitude in the follicular, preovulatory, and mid-luteal phases. These results suggest that caffeine increases performance in the 15-s Wingate test in women athletes and it might be considered an ergogenic aid to increase anaerobic performance in eumenorrhoeic women during their menstrual cycle. post-print 486 KB

p-Synephrine, the principal alkaloid of bitter orange (Citrus aurantium), is widely used in dietary supplements for weight loss due to its purported effect of increasing fat oxidation. However, there is a paucity of scientific information about its effectiveness in enhancing fat oxidation during exercise. The aim of this investigation was to determine the effect of an acute dose of p-synephrine on substrate oxidation during prolonged and constant intensity exercise.In a double-blind and randomized experiment, 14 healthy subjects performed two acute experimental trials after ingesting either p-synephrine (3 mg kgIn comparison to the placebo, energy expenditure during 1 h of cycling remained unchanged with p-synephrine (698 ± 129 vs. 686 ± 123 kcal, P = 0.08). However, p-synephrine increased whole-body fat oxidation (33.6 ± 10.4 vs. 37.3 ± 9.8 g, P 0.01) while also reducing carbohydrate oxidation (99.5 ± 30.4 vs. 85.0 ± 28.4 g, P 0.01). However, the magnitude of the shift on substrate oxidation induced by p-synephrine was small.Acute ingestion of p-synephrine augments fat oxidation during prolonged and constant-intensity exercise.

Purpose p-Synephrine, the principal alkaloid of bitter orange (Citrus aurantium), is widely used in dietary supplements for weight loss due to its purported effect of increasing fat oxidation. However, there is a paucity of scientific information about its effectiveness in enhancing fat oxidation during exercise. The aim of this investigation was to determine the effect of an acute dose of p-synephrine on substrate oxidation during prolonged and constant intensity exercise. Methods In a double-blind and randomized experiment, 14 healthy subjects performed two acute experimental trials after ingesting either p-synephrine (3 mg kg−1) or a placebo (cellulose). Energy expenditure and fat oxidation rates were continuously measured by indirect calorimetry during 1 h of continuous cycling at Fatmax, the intensity that induces maximal fat oxidation rate. Results In comparison to the placebo, energy expenditure during 1 h of cycling remained unchanged with p-synephrine (698 ± 129 vs. 686 ± 123 kcal, P = 0.08). However, p-synephrine increased whole-body fat oxidation (33.6 ± 10.4 vs. 37.3 ± 9.8 g, P

Background: Homozygosity for the X-allele in the ACTN3 R577X (rs1815739) polymorphism results in the complete absence of &alpha, actinin-3 in sarcomeres of fast-type muscle fibers. In elite athletes, the ACTN3 XX genotype has been related to inferior performance in speed and power-oriented sports, however, its influence on exercise phenotypes in recreational athletes has received less attention. We sought to determine the influence of ACTN3 genotypes on common exercise phenotypes in recreational marathon runners. Methods: A total of 136 marathoners (116 men and 20 women) were subjected to laboratory testing that included measurements of body composition, isometric muscle force, muscle flexibility, ankle dorsiflexion, and the energy cost of running. ACTN3 genotyping was performed using TaqMan probes. Results: 37 runners (27.2%) had the RR genotype, 67 (49.3%) were RX and 32 (23.5%) were XX. There was a difference in body fat percentage between RR and XX genotype groups (15.7 &plusmn, 5.8 vs. 18.8 &plusmn, 5.5%, effect size, ES, = 0.5 &plusmn, 0.4, p = 0.024), whereas the distance obtained in the sit-and-reach-test was likely lower in the RX than in the XX group (15.3 &plusmn, 7.8 vs. 18.4 &plusmn, 9.9 cm, ES = 0.4 &plusmn, 0.4, p = 0.046). Maximal dorsiflexion during the weight-bearing lunge test was different in the RR and XX groups (54.8 &plusmn, 5.8 vs. 57.7 &plusmn, 5.1 degree, ES = 0.5 &plusmn, 0.5, p = 0.044). Maximal isometric force was higher in the RR than in the XX group (16.7 &plusmn, 4.7 vs. 14.7 &plusmn, 4.0 N/kg, ES = &minus, 0.5 &plusmn, 0.3, p = 0.038). There was no difference in the energy cost of running between genotypes (~4.8 J/kg/min for all three groups, ES ~0.2 &plusmn, 0.4). Conclusions: The ACTN3 genotype might influence several exercise phenotypes in recreational marathoners. Deficiency in &alpha, actinin-3 might be accompanied by higher body fatness, lower muscle strength and higher muscle flexibility and range of motion. Although there is not yet a scientific rationale for the use of commercial genetic tests to predict sports performance, recreational marathon runners who have performed such types of testing and have the ACTN3 XX genotype might perhaps benefit from personalized strength training to improve their performance more than their counterparts with other ACTN3 genotypes.

The ergogenic effect of acute caffeine ingestion has been widely investigated; however, scientific information regarding tolerance to the performance benefits of caffeine, when ingested on a day-to-day basis, is scarce. The aim of this investigation was to determine the time course of tolerance to the ergogenic effects of a moderate dose of caffeine. Eleven healthy active participants took part in a cross-over, double-blind, placebo-controlled experiment. In one treatment, they ingested 3 mg/kg/day of caffeine for 20 consecutive days while in another they ingested a placebo for 20 days. Each substance was administered daily in an opaque unidentifiable capsule, and the experimental trials started 45 min after capsule ingestion. Two days before, and three times per week during each 20-day treatment, aerobic peak power was measured with an incremental test to volitional fatigue (25 W/min) and aerobic peak power was measured with an adapted version of the Wingate test (15 s). In comparison to the placebo, the ingestion of caffeine increased peak cycling power in the incremental exercise test by ~4.0 ±1.3% for the first 15 days (P