The Effects of Amorphous Calcium Carbonate (ACC) Supplementation on Resistance Exercise Performance in Women.

The effects of 9 weeks of amorphous calcium carbonate (ACC) supplementation (1000 mg/day) and resistance exercise training (RT) on one repetition maximum (1-RM) values were tested. Thirty-one women (33.1 ± 7.3 y) were randomly assigned into a supplement (ACC, n = 14) or a placebo (PL, n = 17) group. On day 1 and following 9 weeks of intervention, the participants underwent anthropometric measurements and filled out a food frequency questionnaire (FFQ) and sports injuries questionnaires. 1-RM values were measured for the back squat and bench press exercises. All the participants significantly (p = 0.01) improved their mean back squat and bench press 1-RM values (time effect). While no between-group difference was observed in the bench press 1-RM values, the ACC groups' mean post-pre bench press 1-RM differences (Δ1-RM) were significantly higher than in the PL group, expressed in kg (p = 0.049), per body mass (p = 0.042), or per lean body mass (p = 0.035). No significant interaction was observed for time X group effect (p = 0.421). No differences (within- or between-groups) were observed in the anthropometric values or in the questionnaires' results. ACC supplementation revealed an ergogenic effect by augmenting the improvement of maximum amount generated force, which can possibly be attributed to the calcium and/or the carbonate components.

The effect of probiotic supplementation on performance, inflammatory markers and gastro-intestinal symptoms in elite road cyclists.

BACKGROUND: Elite athletes may suffer from impaired immune function and gastro-intestinal (GI) symptoms, which may affect their health and may impede their performance. These symptoms may be reduced by multi-strain probiotic supplementation. Therefore, the aim of the current study is to examine the effects of probiotic supplementation on aerobic fitness characteristics, inflammatory markers and incidence and severity of GI symptoms in elite cyclists. METHODS: Twenty-seven male cyclists, ranked elite or category 1 level competitions, were randomly assigned to a multi-strain probiotic-supplemented group (E, n = 11) or placebo group (C, n = 16). All participants visited the laboratory at the beginning of the study and following 90 d of supplementation/placebo. Prior to testing, all participants completed a GI symptoms questionnaire and underwent physical and medical examination, and anthropometric measurements. Venous blood was drawn for inflammatory markers analysis. The cyclists then underwent maximal oxygen consumption (VO2max) test and time-to-fatigue (TTF) test at 85 % of maximal power, 3 h following the VO2max test. All testing procedures were repeated after 90 d of probiotic / placebo treatment (double blind design). RESULTS: Lower incidence of nausea, belching, and vomiting (P < 0.05) at rest, and decreased incidence of GI symptoms during training were found in E group vs. C Group, respectively (∆GI -0.27 ± 0.47 % vs. 0.08 ± 0.29 %, P = 0.03), no significant changes were observed in the incidence of total overall GI symptoms (∆GI -5.6 ± 14.7 % vs. 2.6 ± 11.6 %, P = 0.602) Mean rate of perceived exertion (RPE) values during the TTF were lower in E group (∆RPE: -0.3 ± 0.9 vs. 0.8 ± 1.5, P = 0.04). No significant changes were measured between and within groups in VO2max and TTF values, mean levels of C-reactive protein (CRP), IL-6-and tumor necrosis factor alpha (TNFα) values following treatment. CONCLUSIONS: Probiotics supplementation may have beneficial effects on GI symptoms in elite cyclists. Future studies, using higher doses and during different training seasons, might help understanding the effects of probiotic supplementation on elite athletes' health and performance. TRIAL REGISTRATION: NIH clinicaltrial.gov #NCT02756221 Registered 25 April 2016.

A study on the relationship between exercise addiction, abnormal eating attitudes, anxiety and depression among athletes in Israel.

BACKGROUND AND AIMS: The aim of this study was to investigate the relationship between exercise addiction, abnormal eating attitudes, anxiety, and depression among competitive and amateur athletes. METHODS: Participants were 100 athletes of mean age 28.3 years (18-62), of which there were 67 males and 35 females. The sample consisted of competitive and amateur athletes who participated in individual and group sports. They filled in the Exercise Addiction Inventory, Body Shape Questionnaire, a questionnaire assessing Eating Attitudes Test, Spielberger State-Trait Anxiety Inventory, and Beck Depression Inventory (BDI). RESULTS: Ratings of exercise addiction were positively correlated with BDI scores across the study sample. Exercise addiction ratings were associated with abnormal eating attitudes, but not with trait or state anxiety. Athletes engaging in individual sports scored marginally higher on depression scores than group athletes but there was no difference in depression scores between competitive and amateur athletes. Multiple regression analysis revealed that abnormal eating attitudes contributed significantly to ratings of exercise addiction and explained 7.7% of the variance. According to the Sobel test, the difference in the association between exercise addiction and eating disorder was significant. Therefore, body shape was a mediating factor between eating disorder and exercise addiction. DISCUSSION AND CONCLUSIONS: This study extends our preliminary findings of an association between exercise addiction and depression. Second, abnormal eating attitudes may explain most of the variance of exercise addiction. This is a further support for previous evidence of comorbidity between exercise addiction and eating disorders.

Recovery of upper-body muscle power after short intensive exercise: comparing boys and men.

PURPOSE: Boys' lower-body muscle power generation (PO) recovers faster than men's following intensive exercise. The purpose of this study was to examine whether boys differ from adult men in recovering from upper-body muscle power generation following intensive exercise. METHODS: Fifteen prepubertal boys (M ± SD age 10.6 ± 1.0 years) and 13 men (31.1 ± 5.0 years) performed two upper-body Wingate Anaerobic Tests (WAnT), separated by either 2-min or 10-min recovery intervals. WAnT parameters, pre-and post-WAnT heart rates (HR), and blood lactate ([La]) were measured during recovery from the WAnTs. RESULTS: Boys' mean power (MP) of the repeated WAnT (WAnT2) following 2- and 10-min recoveries was 97.3 ± 7.2% and 99.4 ± 3.9%, respectively, compared to MP of the first test (WAnT1) (p > 0.05 for both tests). In contrast, in men's MP of the WAnT2 following the 2-min recovery, was significantly lower than that of the WAnT1 (84.4 ± 6.7%, p = 0.0001). While boys' and men's HR recovery after 2 min differed significantly (p = 0.046), no between-group differences were found following the 10-min recovery. Peak [La] in boys was 37-44% lower than that in men (p = 0.002). CONCLUSIONS: The faster recovery of PO in boys after supra-maximal upper-body exercise is partially explained by the lower power generated by boys, attributed in part to a lower anaerobic capacity and to the greater relative contribution of aerobic processes to performance and recovery from anaerobic-type tasks. Further research is needed to determine the physiologic, neurologic and biochemical basis of the rapid muscle power recovery in children.

The choice of freely preferred cadence by trained nonprofessional cyclists may not be characterized by mechanical efficiency.

BACKGROUND: Most cycling studies involve professional cyclists. Because training may affect riding style, it is of interest to determine the physiological basis for the personal choice of cycling cadence in nonprofessional cyclists. METHODS: Eleven nonprofessional (5.2±1.7-year-riding experience) male road cyclists, aged 35.0±11.0 years, underwent four separate laboratory test sessions. The first two sessions included habituation, anthropometry, V˙O2max,$\dot V{{\text{O}}_{\text{2}}}{\text{max}},$ and lactate threshold (LaTH) measurements. Freely preferred cadence at LaTH was determined during the second session (mean±SD=94.7±2.9 rev·min-1). During the third and fourth sessions participants performed LaTH tests at 60 and 95 rev·min-1 in a randomized order, with power output (PO) increments of 25 W every 4 min, up to ~90% of V˙O2max.$\dot V{{\text{O}}_{\text{2}}}{\text{max}}{\text{.}}$ Results: V˙O2,$\dot V{{\text{O}}_{\text{2}}},$ expired ventilation (V˙E),$({\dot V_E}),$ blood lactate (La), and calculated net mechanical efficiency (MEnet) rose with increased PO. At 95 rev·min-1, V˙O2, V˙E,$\dot V{{\text{O}}_2},{\text{ }}{\dot V_{\text{E}}},$ and La were significantly higher than at 60 rev·min-1 at all POs. MEnet at 95 rev·min-1 was lower than at 60 rev·min-1. Mean PO attained at LaTh did not differ significantly between 60 and 95 rev·min-1 (220.9±29.0 and 214.5±9.2 W, respectively). La values at LaTH were higher at 95 rev·min-1 than at 60 rev·min-1 (3.01±0.17 vs. 2.10±0.13 mM, p<0.05, respectively). CONCLUSIONS: Our findings indicate that mechanical and physiological efficiencies may not determine the choice of cycling cadence by nonprofessional cyclists. This choice may reflect the need to maintain endurance at the expense of riding at a lower than optimal riding efficiency.

The effect of caffeine on energy balance.

The global prevalence of obesity has increased considerably in the last two decades. Obesity is caused by an imbalance between energy intake (EI) and energy expenditure (EE), and thus negative energy balance is required to bring about weight loss, which can be achieved by either decreasing EI or increasing EE. Caffeine has been found to influence the energy balance by increasing EE and decreasing EI, therefore, it can potentially be useful as a body weight regulator. Caffeine improves weight maintenance through thermogenesis, fat oxidation, and EI. The sympathetic nervous system is involved in the regulation of energy balance and lipolysis (breakdown of lipids to glycerol and free fatty acids) and the sympathetic innervation of white adipose tissue may play an important role in the regulation of total body fat. This article reviews the current knowledge on the thermogenic properties of caffeine, and its effects on appetite and EI in relation to energy balance and body weight regulation.

A study on the relationship between compulsive exercise, depression and anxiety.

BACKGROUND AND AIMS: Exercise and physical activity are beneficial both physically and psychologically but a few individuals use exercise excessively resulting in physical and even psychological damage. There is evidence for bi-directional relationship between exercise with depression and anxiety showing that exercise can reduce anxiety and depression, whereas a lack of exercise is associated with higher levels of anxiety and depression. METHODS: This study used questionnaires assessing compulsive exercise, anxiety and depression among 20 professional regular exercisers and 51 recreational regular exercisers. RESULTS: Results showed that ratings of compulsive exercise were associated with ratings of anxiety and depression among individuals who exercise for professional and recreational purpose. Secondly, individuals who exercise for professional purpose were more depressed than individuals who exercise for recreational purpose, but did not exhibit higher trait anxiety ratings. Thirdly, individuals who exercise for recreational purpose showed an association between ratings of compulsive exercise and depression but not with ratings of trait anxiety. DISCUSSION: Individuals who exercise for professional and recreational purpose may use it as a means for alleviating depression and anxiety although this small sample of recreational and professional sportsmen showed clinical levels of anxiety and depression that may require further clinical treatment.

Exercise addiction- diagnosis, bio-psychological mechanisms and treatment issues.

Exercise and sports activity are beneficial both physically and psychologically but excessive exercise may have adverse physiological and psychological effects. There are methodological issues in the definition, diagnosis and etiology of exercise addiction. Several questionnaires and diagnostic tools have been developed and validated and they show high validity and reliability. Exercise addiction has been suggested as having an obsessive-compulsive dimension as well as rewarding aspects that may include it among the behavioral addictions. Biological studies show that in rodents, exercise such as wheel running activates the dopamine reward system and thus contributing to stress reduction. Further evidence suggests that running is associated with endorphins and cannabinoids thus explaining the "runners high" or euphoric feelings that may lead to exercise addiction. Genetic studies suggest that genes which control preference for drugs also control the preference for naturally rewarding behaviors such as exercise. Psychological studies also explain exercise addiction in terms of reward, habituation, social support, stress-relief, avoidance of withdrawal and reduction of anxiety. It has been suggested that exercise addiction is a part of a continuum of sportive activity that develops in stages from the recreational exercise to at-risk exercise, problematic exercise and finally into exercise addiction. Assessment and treatment should take into account the various stages of exercise addiction development, its comorbidity with other psychiatric disorders such as eating disorders or substance use and alcohol disorders. Treatment approaches for exercise addiction are based on the cognitive-behavioral approach but little is known about their effectiveness. A single-case study shows promise of pharmacological treatment for exercise addiction and further studies are required. This review summarizes diagnostic and phenomenology of exercise addiction with emphasis on physiological and neuro-pharmacological mechanisms responsible for its rewarding and addictive properties.

[Energy balance, body composition and the female athlete triad syndrome].

With the rising participation of women in sports events, the prevalence of eating disorders and the female athlete triad (FTS), a syndrome of disordered eating, amenorrhea, and osteoporosis, have also increased in recent years. FTS is often seen in sports that emphasize thinness (e.g. gymnastics, figure skating and dancing) and also in endurance events. Elements of the FTS are pathophysiologically linked, leading to several disease risks and even to mortality. In spite of the considerable knowledge about sports nutrition, there is no consensus as to the correct nutrition regime for the female athlete. There is consensus that minimizing fluctuations in 'target-body-weight' is an indication of a long-term energy balance. Female athletes (e.g. in endurance events and gymnastics) are less likely to achieve the recommended carbohydrates (CHO) and fat consumption due to chronic or episodic constraints of total energy intake while struggling to achieve or maintain low levels of body fat. It is recommended that dietary CHO and fat content be increased to preserve fat-free mass thus enhancing health and performance. Energy balance should also be maintained during recesses. Furthermore, within-day episodes of energy deficits/surplus (measured by the frequency and/or magnitude of the episodes) should be monitored and treated closest to the time of the incidents.

Exercise with and without an insulin pump among children and adolescents with type 1 diabetes mellitus.

BACKGROUND: The use of insulin pumps is becoming a popular technique for insulin delivery among patients with type 1 diabetes mellitus (T1DM), but there is no consensus regarding the guidelines for proper pump use during exercise. OBJECTIVE: To investigate the physiologic responses and risk of hypoglycemia among children and adolescents with T1DM when exercising with the pump on (PO) (50% of the basal rate) or pump off (PF). METHODS: Ten subjects with T1DM (6 female subjects and 4 male subjects), 10 to 19 years of age, performed prolonged exercise (40-45 minutes) on a cycle ergometer approximately 2 hours after a standard breakfast and an insulin (Lispro) bolus. Complex carbohydrates (20 g) were provided before and after the exercise. Each patient exercised once with PO and once with PF, in a randomized, crossover (single-blind) manner. During exercise and 45 minutes of recovery, subjects were monitored for cardiorespiratory, metabolic, and hormonal responses. Blood glucose concentrations were recorded for 24 hours after exercise, with a continuous glucose monitoring system, to document late hypoglycemic events. RESULTS: During exercise, blood glucose concentrations decreased by 59 +/- 58 mg/dL (mean +/- SD: 29 +/- 24%) with PF and by 74 +/- 51 mg/dL (35.5 +/- 18%) with PO (not significant). No significant differences were found in cortisol, growth hormone, or noradrenaline levels between PO and PF. There were no differences in cardiorespiratory parameters, blood lactate concentrations, or free fatty acids concentrations between pump modes. Hypoglycemic events during exercise were asymptomatic and occurred for 2 subjects with PO and 2 with PF. Nine subjects had late hypoglycemia after PO, compared with 6 after PF (not significant). CONCLUSIONS: We found no advantage for subjects with either PO or PF during exercise, and we noted that late hypoglycemia was more common than hypoglycemia during exercise. However, PO was associated with a trend of increased risk for late hypoglycemia. We recommend that the pump be removed or turned off during prolonged exercise and that blood glucose concentrations be monitored for several hours after exercise, regardless of the pump mode.

Mechanical efficiency of normal-weight prepubertal boys predisposed to obesity.

PURPOSE: To compare 1) energy expenditure during rest and during submaximal exercise, and 2) the mechanical efficiency of normal-weight boys liable to obesity with normal-weight boys who are not liable to obesity. METHODS: Two groups of prepubertal boys, aged 9-12 yr were compared, one with both parents of normal weight (NP, 20 < or = BMI < or = 27, N = 20) and the other (N = 20) with one obese parent (OP, BMI > or = 30). RESULTS: No significant differences were found between the two groups in the anthropometric measurements (means +/- SD): body mass (32.9 +/- 5.4 and 31.5 +/- 3.1 kg, NP and OP, respectively), stature (141.0 +/- 6.2 and 140.0 +/- 5.5 cm, NP and OP, respectively), and body fat (16.6 +/- 3.5 and 15.1 +/- 3.5%, NP and OP, respectively). Likewise, there were no differences in the reported physical activity habits. No differences were observed in the resting metabolic rate values between the two groups (5.071 +/- 0.351 and 4.956 +/- 0.386 MJ x d(-1) , NP and OP, respectively). Submaximal VO2 at 30, 45, and 60 W was similar in the two groups (0.63 +/- 0.05, 0.78 +/- 0.06, and 0.92 +/- 0.08; and 0.63 +/- 0.06, 0.78 +/- 0.08, and 0.95 +/- 0.08 L x min(-1), NP and OP, respectively). Likewise, the mechanical efficiency, calculated at 30, 45, and 60 W was similar in both groups (19.5 +/- 2.3, 21.8 +/- 2.2, 23.4 +/- 2.5%; and 19.5 +/- 3.0, 21.9 +/- 2.9, 22.6 +/- 2.5%, NP and OP, respectively. No differences were found between groups in their VO2peak (38.4 +/- 3.8 and 40.4 +/- 4.9 mL x kg(-1) x min(-1), NP and OP, respectively). CONCLUSION: These data suggest that energy expenditure during rest and exercise may not be used to predict future obesity in normal-weight prepubertal boys predisposed to obesity.