Endocrinology and Metabolism

2015 ◽  
Vol 27 (1) ◽  
pp. 30-33
Author(s):  
Alon Eliakim
Keyword(s):  
Energy Intake ◽  
Female Athletes ◽  
Swimming Performance ◽  
Sport Performance ◽  
Energy Deficit ◽  
Energy Status ◽  
Ovarian Suppression ◽  
Metabolic Hormones ◽  
Highly Correlated ◽  
The Impact

Introduction:Competitive female athletes restrict energy intake and increase exercise energy expenditure frequently resulting in ovarian suppression. The purpose of this study was to determine the impact of ovarian suppression and energy deficit on swimming performance (400-m swim velocity).Methods:Menstrual status was determined by circulating estradiol (E2) and progesterone (P4) in ten junior elite female swimmers (15-17 yr). The athletes were categorized as cyclic (CYC) or ovarian-suppressed (OVS). They were evaluated every 2 weeks for metabolic hormones, bioenergetic parameters, and sport performance during the 12-week season.Results:CYC and OVS athletes were similar (p > .05) in age (CYC = 16.2 ± 1.8 yr, OVS = 17 ± 1.7 yr), body mass index (CYC = 21 ± 0.4 kg·m, OVS = 25 ± 0.8 kg·m), and gynecological age (CYC = 2.6 ± 1.1 yr, OVS = 2.8 ± 1.5 yr). OVS had suppressed P4 (p < .001) and E2 (p = .002) across the season. Total triiodothyronine (TT3) and insulin-like growth factor (IGF-1) were lower in OVS (TT3: CYC = 1.6 ± 0.2 nmol·L, OVS = 1.4 ± 0.1 nmol·L, p < .001; IGF-1: CYC = 243 ± 1 μg·mL, OVS = 214 μg·mL p < .001) than CYC at week 12. Energy intake (p < .001) and energy availability (p < .001) were significantly lower in OVS versus CYC. OVS exhibited a 9.8% decline in Δ400-m swim velocity compared with an 8.2% improvement in CYC at week 12.Conclusions:Ovarian steroids (P4 and E2), metabolic hormones (TT3 and IGF-1), and energy status markers (EA and EI) were highly correlated with sport performance. This study illustrates that when exercise training occurs in the presence of ovarian suppression with evidence for energy conservation (i.e., reduced TT3), it is associated with poor sport performance. These data from junior elite female athletes support the need for dietary periodization to help optimize energy intake for appropriate training adaptation and maximal sport performance

scholarly journals The Impact of Menstrual Cycle Phase on Athletes’ Performance: A Narrative Review

2021 ◽  
Vol 18 (4) ◽  
pp. 1667
Author(s):  
Mikaeli Anne Carmichael ◽  
Rebecca Louise Thomson ◽  
Lisa Jane Moran ◽  
Thomas Philip Wycherley
Keyword(s):  
Menstrual Cycle ◽  
Physical Performance ◽  
Female Athletes ◽  
Sport Performance ◽  
Performance Outcomes ◽  
Narrative Review ◽  
Cycle Phase ◽  
Menstrual Cycle Phase ◽  
Objective Performance ◽  
The Impact

The effect of the menstrual cycle on physical performance is being increasingly recognised as a key consideration for women’s sport and a critical field for further research. This narrative review explores the findings of studies investigating the effects of menstrual cycle phase on perceived and objectively measured performance in an athletic population. Studies examining perceived performance consistently report that female athletes identify their performance to be relatively worse during the early follicular and late luteal phases. Studies examining objective performance (using anaerobic, aerobic or strength-related tests) do not report clear, consistent effects of the impact of menstrual cycle phase on physical performance. Overall sport performance can be influenced by both perceived and physical factors. Hence, to optimise performance and management of eumenorrheic female athletes, there is a need for further research to quantify the impact of menstrual cycle phase on perceived and physical performance outcomes and to identify factors affecting variability in objective performance outcomes between studies.

scholarly journals Understanding female coaches’ and practitioners’ experience and support provision in relation to the menstrual cycle

2021 ◽  
pp. 174795412110585
Author(s):  
Natalie Brown ◽  
Camilla J Knight
Keyword(s):  
Menstrual Cycle ◽  
Female Athletes ◽  
Sport Performance ◽  
Structured Interviews ◽  
Support Provision ◽  
Supportive Environment ◽  
Personal Experiences ◽  
Ethical Approval ◽  
The Impact ◽  
Female Coaches

The study aimed to develop an understanding of female coaches’ and sport science practitioners’ experience and support provision in relation to the menstrual cycle when working with female athletes. Following receipt of institutional ethical approval, 14 female coaches and practitioners (32.9 ± 6.9 years) participated in individual semi-structured interviews. Following analysis, two themes were developed: (1) Knowledge and awareness and (2) Support and management. Overall, it appeared that participants varied in their understanding and awareness of the impact of the menstrual cycle on sport performance, somewhat influenced by their own personal experiences. Participants’ knowledge and awareness subsequently impacted the support they provided to female athletes. Additionally, individual experiences and perceived secrecy relating to the menstrual cycle impacted on the informational and emotional support participants provided. Together, the findings highlight the importance of all coaches and practitioners enhancing their knowledge and understanding regarding the menstrual cycle and proactively providing support to athletes. Education to enhance coaches’ and practitioners’ knowledge and understanding will help to create a more open and supportive environment in sport, hopefully allowing for personal discomfort regarding the menstrual cycle to be addressed.

Nutritional intervention promoting Mediterranean diet improves dietary intake and enhances score adherence in adolescent athletes

2020 ◽  
Vol 13 (3) ◽  
pp. 237-253
Author(s):  
Rokia Sahnoune ◽  
Malika Bouchenak
Keyword(s):  
Mediterranean Diet ◽  
Energy Intake ◽  
Nutritional Intervention ◽  
Fiber Intake ◽  
Adequate Intake ◽  
Total Proteins ◽  
Adolescent Athletes ◽  
24 Hour Recall ◽  
The Impact ◽  
Kidmed Index

BACKGROUND: Appropriate nutrition is important to maintain health, growth, and development of adolescent athlete performance. OBJECTIVE: To evaluate the impact of nutritional intervention (NI) promoting Mediterranean diet (MD), on food consumption, and adherence to MD, in scholar adolescent athletes. METHODS: Eighty athletes (Females/Males, 39/41) aged 15±1 years participated to NI. MD Adherence was assessed, using Kidmed index, at baseline, and at 6 months. Food intake was evaluated by 24-hour recall at baseline, and at four NI times. RESULTS: At baseline, 61% of athletes had poor MD adherence, and after NI, this value decreased to 10%. At 6 months of NI, 73% of males vs 46% of females had good MD adherence (≥8). Energy intake represented 2369 Kcal/d, at baseline, and was less than recommended value. After NI, significant increase was observed in energy intake (p = 0.001). Mean fiber intake (19 and 21 g/d in females and males, respectively) was less than adequate intake (26/38 g/d), but increased after NI (p = 0.000). Enhancement was noted in total, and complex carbohydrates, and total proteins, and values were increased with time (p = 0.000, p = 0.000, p = 0.003). CONCLUSION: Nutritional intervention, based on Mediterranean diet, improves total energy, and macronutrients intake, and increases MD adherence scores in adolescents athletes.

Adolescent athletes and nutrition – analysis of two groups of children

2020 ◽  
pp. 1-6
Author(s):  
Tatyana Dzimbova
Keyword(s):  
Energy Expenditure ◽  
Energy Intake ◽  
Eating Habits ◽  
Energy Deficit ◽  
Young Athletes ◽  
Adolescent Athletes ◽  
Basketball Players ◽  
Calcium Magnesium ◽  
The Right

Introduction. Proper nutrition is crucial for child and adolescent athletes to maintain growth and development and to achieveoptimal results in sports. It is very important to balance the energy expenditure with the energy intake in order to prevent the energy deficit or excess.Materials and methods. Subjects involved in two different sports participated in the study: 13 gymnasts (age 13.8 ± 4.1 years, height 153.4 ± 11.3 cm, weight 47.1 ± 10.5 kg) and 15 basketball players (age 15.5 ± 1.1 years, height 176.7 ± 7.9 cm, weight 65.2 ± 10.7 kg). Determination of total energy expenditure was made by prediction equations. The subjects maintained a food records for 5 consecutive days, which were processed in the ASA24 system of the NCI. Results and discussion. Energy intake in both groups is sufficient to meet the daily needs, development of young athletes andprovide the energy needed in training. The intake of three minerals (calcium, magnesium and potassium) and three vitamins (D, E and A) was lower than recommended values in both groups.Conclusion. As a result of the busy schedule of adolescent athletes, their main meals are out of home, and the proportion of highly processed foods containing small amounts of important vitamins and minerals is high. The main recommendations include dairy products, fruits, vegetables and whole grains. The idea behind the changes is to give young athletes the right diet and the right eating habits.

scholarly journals Influence of Menstrual Cycle or Hormonal Contraceptive Phase on Energy Intake and Metabolic Hormones—A Pilot Study

Endocrines ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 79-90
Author(s):  
Johanna K. Ihalainen ◽  
Ida Löfberg ◽  
Anna Kotkajuuri ◽  
Heikki Kyröläinen ◽  
Anthony C. Hackney ◽  
...  
Keyword(s):  
Menstrual Cycle ◽  
Energy Intake ◽  
Hormonal Contraceptive ◽  
Group Differences ◽  
Metabolic Hormones ◽  
Recreational Athletes ◽  
Total Ghrelin ◽  
17Β Estradiol ◽  
The Mean ◽  
And Training

Sex hormones are suggested to influence energy intake (EI) and metabolic hormones. This study investigated the influence of menstrual cycle (MC) and hormonal contraceptive (HC) cycle phases on EI, energy availability (EA), and metabolic hormones in recreational athletes (eumenorrheic, NHC = 15 and monophasic HC-users, CHC = 9). In addition, 72-h dietary and training logs were collected in addition to blood samples, which were analyzed for 17β-estradiol (E2), progesterone (P4), leptin, total ghrelin, insulin, and tri-iodothyronine (T3). Measurements were completed at four time-points (phases): Bleeding, mid-follicular (FP)/active 1, ovulation (OVU)/active 2, mid-luteal (LP)/inactive in NHC/CHC, respectively. As expected, E2 and P4 fluctuated significantly in NHC (p < 0.05) and remained stable in CHC. In NHC, leptin increased significantly between bleeding and ovulation (p = 0.030) as well as between FP and OVU (p = 0.022). No group differences in other measured hormones were observed across the MC and HC cycle. The mean EI and EA were similar between phases, with no significant differences observed in macronutrient intake over either the MC or HC. While the MC phase might have a small, but statistically significant effect on leptin, the findings of the present study suggest that the MC or HC phase does not significantly alter ad libitum EI or EA in recreational athletes.

Energy Intakes of Ultraendurance Cyclists During Competition, an Observational Study

2012 ◽  
Vol 22 (1) ◽  
pp. 19-23 ◽  
Author(s):  
Katherine E. Black ◽  
Paula M.L. Skidmore ◽  
Rachel C. Brown
Keyword(s):  
Observational Study ◽  
Energy Intake ◽  
Energy Requirement ◽  
Negative Relationship ◽  
Computer Software ◽  
High Energy ◽  
Energy Deficit ◽  
Food Diary ◽  
Food And Drink ◽  
And Performance

Endurance events >10 hr are becoming increasingly popular but provide numerous physiological challenges, several of which can be attenuated with optimal nutritional intakes. Previous studies in ultraendurance races have reported large energy deficits during events. The authors therefore aimed to assess nutritional intakes in relation to performance among ultraendurance cyclists. This observational study included 18 cyclists in a 384-km cycle race. At race registration each cyclist’s support crew was provided with a food diary for their cyclist. On completion of the race, cyclists were asked to recall their race food and drink intakes. All food and fluids were analyzed using a computer software package. Mean (SD) time to complete the race was 16 hr 21 min (2 hr 2 min). Mean (SD) energy intake was 18.7 (8.6) MJ, compared with an estimated energy requirement for the race of 25.5 (7.4) MJ. There was a significant negative relationship between energy intake and time taken to complete the race (p = .023, r2 = −.283). Mean (SD) carbohydrate, fat, and protein intakes were 52 (27), 15.84 (56.43), and 2.94 (7.25) g/hr, respectively. Only carbohydrate (p = .015, r2 = −.563) and fat intake (p = .037, r2 = −.494) were associated with time taken to complete the race. This study demonstrates the difficulties in meeting the high energy demands of ultraendurance cycling. The relationship between energy intake and performance suggests that reducing the energy deficit may be advantageous. Given the high carbohydrate intakes of these athletes, increasing energy intake from fat should be investigated as a means of decreasing energy deficits.

scholarly journals Urinary and anal incontinence among female gymnasts and cheerleaders—bother and associated factors. A cross-sectional study

2021 ◽  
Author(s):  
Kristina Lindquist Skaug ◽  
Marie Ellström Engh ◽  
Helena Frawley ◽  
Kari Bø
Keyword(s):  
Pelvic Floor ◽  
Anal Incontinence ◽  
Female Athletes ◽  
Cross Sectional Study ◽  
Sport Performance ◽  
Sports Performance ◽  
International Consensus ◽  
Cross Sectional ◽  
Negative Effect ◽  
Female Gymnasts

Abstract Introduction and hypothesis Artistic gymnastics, team gymnastics and cheerleading are sports including high-impact activities. It is presumed that the athletes’ pelvic floor must be functioning well to prevent urinary (UI) and anal incontinence (AI) during sports. The aim of this study was to investigate the prevalence and risk factors for UI and AI in female artistic gymnasts, team gymnasts and cheerleaders; the influence of UI and AI on daily living and sport performance; and the athletes’ knowledge about the pelvic floor muscles (PFM). Methods All female athletes ≥ 12 years of age competing in ≥ 1 National Championship in artistic gymnastics, team gymnastics or cheerleading in 2018/2019 were invited. International Consensus on Incontinence Questionnaires were used to assess the prevalence/bother of UI and AI. Results Among the 319 gymnasts and cheerleaders who participated, the prevalence of UI and AI was 67% and 84%, respectively. Age, training ≥ 4 days/week and straining to void were significantly associated with stress urinary incontinence (SUI) and years of training with AI. Eighty-three percent of athletes with SUI reported a negative effect on sports performance, 22% would occasionally avoid training or specific exercises because of leakage, and 28% used pads for protection. Forty-one percent of the athletes had never heard about the PFM, and 74% reported an interest in PFM training to prevent/treat UI or AI. Conclusions UI and AI were prevalent in female gymnasts and cheerleaders, and SUI negatively influenced sport performance. The athletes’ knowledge about the PFM was limited.

scholarly journals Climatic Analysis of Wind Patterns to Enhance Sailors’ Performance during Races

Climate ◽  
2021 ◽  
Vol 9 (5) ◽  
pp. 80
Author(s):  
Pietro Masino ◽  
Roberto Bellasio ◽  
Roberto Bianconi ◽  
Angelo Besana ◽  
Alessandro Pezzoli
Keyword(s):  
Support Service ◽  
Sport Performance ◽  
Meteorological Conditions ◽  
Meteorological Variables ◽  
Wind Data ◽  
Weather Research And Forecasting ◽  
Innovative Method ◽  
Combined Use ◽  
The Impact ◽  
Wind Patterns

The impact of environmental and meteorological conditions when dealing with sport performance has been demonstrated by several studies carried out in recent years. Among the meteorological variables with the greatest effect are temperature, humidity, precipitation, and wind direction and speed. This research focused on analyzing and forecasting the wind patterns occurring in Enoshima Bay (Japan). In particular, the objective of this study was to provide support and guidance to sailors in the preparation of the race strategy, thanks to an in-depth knowledge of these meteorological variables. To do this, an innovative method was used. First, through the combined use of Weather Research and Forecasting (WRF) and CALMET models, a simulation was performed, in order to reconstruct an offshore database of a recent 10-year period (2009–2018) over the race area, inside the bay. Subsequently, the verification of hind-cast was performed: the wind data measured at sea were compared with the data extracted from the CALMET database to verify the validity of the model. The verification was performed through three statistical indexes: BIAS, MAE, and PCC. The analysis showed mixed results, depending on the examined pattern, but made it possible to identify the days that best simulated the reality. Then, the wind data from the selected days were summarized and collected in plots, tables, and maps to design a decision support service (DSS), in order to provide athletes with the necessary information in a simple and effective way. In conclusion, we state that the application of this method extends beyond the sports field. Indeed, the study of wind patterns may be necessary in the design of actions to contrast and adapt to climate change, particularly in coastal areas.

scholarly journals The Influence of Trading Locations on Equity Returns

2016 ◽  
Vol 12 (12) ◽  
pp. 188
Author(s):  
Nguyen N.T. Vo
Keyword(s):  
Risk Premium ◽  
Stock Price ◽  
Listed Companies ◽  
Equity Returns ◽  
Stock Exchanges ◽  
Home Market ◽  
Trade Effect ◽  
Market Index ◽  
Highly Correlated ◽  
The Impact

This paper evaluates the impact of trading locations on equity returns by examining the stock price behaviour of three Anglo-Dutch dual-listed companies which result from mergers where two corporations agree to function as a single operating business, but maintain separate identities. The shares of these stocks are traded not only in their home market but also on several US stock exchanges in the form of American Depository Receipts. Regressing the return differentials on these dual-listed and cross-listed stocks on the relative market index returns and currency changes provides evidence of an apparent violation of the Law of One Price. The regression results show that the return on each part of dual-listed companies is highly correlated with the market on which it is most intensively traded. Similarly, returns on cross-listed stocks have considerably higher co-movement with US market indices and considerably lower co-movement with home-market indices than their home-market counterparts. Market risk premium is not a significant explanatory variable of the location of trade effect.

scholarly journals The effect of breakfast on appetite regulation, energy balance and exercise performance

2015 ◽  
Vol 75 (3) ◽  
pp. 319-327 ◽  
Author(s):  
David J. Clayton ◽  
Lewis J. James
Keyword(s):  
Energy Balance ◽  
Energy Expenditure ◽  
Energy Intake ◽  
Exercise Performance ◽  
Intervention Studies ◽  
Precise Determination ◽  
Positive Energy ◽  
Cross Sectional ◽  
Positive Energy Balance ◽  
The Impact

The belief that breakfast is the most important meal of day has been derived from cross-sectional studies that have associated breakfast consumption with a lower BMI. This suggests that breakfast omission either leads to an increase in energy intake or a reduction in energy expenditure over the remainder of the day, resulting in a state of positive energy balance. However, observational studies do not imply causality. A number of intervention studies have been conducted, enabling more precise determination of breakfast manipulation on indices of energy balance. This review will examine the results from these studies in adults, attempting to identify causal links between breakfast and energy balance, as well as determining whether consumption of breakfast influences exercise performance. Despite the associations in the literature, intervention studies have generally found a reduction in total daily energy intake when breakfast is omitted from the daily meal pattern. Moreover, whilst consumption of breakfast supresses appetite during the morning, this effect appears to be transient as the first meal consumed after breakfast seems to offset appetite to a similar extent, independent of breakfast. Whether breakfast affects energy expenditure is less clear. Whilst breakfast does not seem to affect basal metabolism, breakfast omission may reduce free-living physical activity and endurance exercise performance throughout the day. In conclusion, the available research suggests breakfast omission may influence energy expenditure more strongly than energy intake. Longer term intervention studies are required to confirm this relationship, and determine the impact of these variables on weight management.

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