Lack of Effect of Typical Rapid-Weight-Loss Practices on Balance and Anaerobic Performance in Apprentice Jockeys

2015 ◽  
Vol 10 (8) ◽  
pp. 972-977 ◽  
Author(s):  
SarahJane Cullen ◽  
Eimear Dolan ◽  
Kate O Brien ◽  
Adrian McGoldrick ◽  
Giles Warrington

Balance and anaerobic performance are key attributes related to horse-racing performance, but research on the impact of making weight for racing on these parameters remains unknown. The purpose of this study was to investigate the effects of rapid weight loss in preparation for racing on balance and anaerobic performance in a group of jockeys.Methods:Twelve apprentice male jockeys and 12 age- and gender-matched controls completed 2 trials separated by 48 h. In both trials, body mass, hydration status, balance, and anaerobic performance were assessed. Between the trials, the jockeys reduced body mass by 4% using weight-loss methods typically adopted in preparation for racing, while controls maintained body mass through typical daily dietary and physical activity habits.Results:Apprentice jockeys decreased mean body mass by 4.2% ± 0.3% (P < .001) with a subsequent increase in dehydration (P < .001). The controls maintained body mass and a euhydrated state. No differences in balance, on the left or right side, or in peak power, mean power, or fatigue index were reported between the trials in either group.Conclusion:Results from this study indicate that a 4% reduction in body mass in 48 h through the typical methods employed for racing, in association with an increase in dehydration, resulted in no impairments in balance or anaerobic performance. Further research is required to evaluate performance in a sport-specific setting and to investigate the specific physiological mechanisms involved.

Author(s):  
Joseph John Matthews ◽  
Ceri Nicholas

There is a lack of research documenting the weight-making practices of mixed-martial-arts (MMA) competitors. The purpose of the investigation was to quantify the magnitude and identify the methods of rapid weight loss (RWL) and rapid weight gain (RWG) in MMA athletes preparing for competition. Seven athletes (mean ± SD, age 24.6 ± 3.5 yrs, body mass 69.9 ± 5.7 kg, competitive experience 3.1 ± 2.2 yrs) participated in a repeated-measures design. Measures of dietary intake, urinary hydration status, and body mass were recorded in the week preceding competition. Body mass decreased significantly (p < .0005) from baseline by 5.6 ± 1.4 kg (8 ± 1.8%). During the RWG period (32 ± 1 hr) body mass increased significantly (p < .001) by 7.4 ± 2.8 kg (11.7 ± 4.7%), exceeding RWL. Mean energy and carbohydrate intake were 3176 ± 482 kcal・day-1 and 471 ± 124 g・day-1, respectively. At the official weigh-in 57% of athletes were dehydrated (1033 ± 19 mOsmol・kg-1) and the remaining 43% were severely dehydrated (1267 ± 47 mOsmol・kg-1). Athletes reported using harmful dehydration-based RWL strategies, including sauna (43%) and training in plastic suits (43%). Results demonstrated RWG greater than RWL, this is a novel finding and may be attributable to the 32 hr duration from weigh-in till competition. The observed magnitude of RWL and strategies used are comparable to those which have previously resulted in fatalities. Rule changes which make RWL impractical should be implemented with immediate effect to ensure the health, safety and wellbeing of competitors.


Vaccines ◽  
2022 ◽  
Vol 10 (1) ◽  
pp. 79
Author(s):  
Mikiko Watanabe ◽  
Angela Balena ◽  
Davide Masi ◽  
Rossella Tozzi ◽  
Renata Risi ◽  
...  

Obesity is associated with a poor COVID-19 prognosis, and it seems associated with reduced humoral response to vaccination. Public health campaigns have advocated for weight loss in subjects with obesity, hoping to eliminate this risk. However, no evidence proves that weight loss leads to a better prognosis or a stronger immune response to vaccination. We aimed to investigate the impact of rapid weight loss on the adaptive immune response in subjects with morbid obesity. Twenty-one patients followed a hypocaloric, very-low-carbohydrate diet one week before to one week after the two mRNA vaccine doses. The diet’s safety and efficacy were assessed, and the adaptive humoral (anti-SARS CoV-2 S antibodies, Abs) and cell-mediated responses (IFNγ secretion on stimulation with two different SARS CoV-2 peptide mixes, IFNγ-1 and IFNγ-2) were evaluated. The patients lost ~10% of their body weight with metabolic improvement. A high baseline BMI correlated with a poor immune response (R −0.558, p = 0.013 for IFNγ-1; R −0.581, p = 0.009 for IFNγ-2; R −0.512, p = 0.018 for Abs). Furthermore, there was a correlation between weight loss and higher IFNγ-2 (R 0.471, p = 0.042), and between blood glucose reduction and higher IFNγ-1 (R 0.534, p = 0.019), maintained after weight loss and waist circumference reduction adjustment. Urate reduction correlated with higher Abs (R 0.552, p = 0.033). In conclusion, obesity is associated with a reduced adaptive response to a COVID-19 mRNA vaccine, and weight loss and metabolic improvement may reverse the effect.


Author(s):  
Kadhiresan R. Murugappan ◽  
Ariel Mueller ◽  
Daniel P. Walsh ◽  
Shahzad Shaefi ◽  
Akiva Leibowitz ◽  
...  

Rapid weight loss or “weight cutting” is a common but potentially harmful practice used in mixed martial arts competition. Following the official weigh-in, competitors refeed and rehydrate themselves in a process known as rapid weight gain (RWG) to realize a potential competitive advantage. While data from surveys and small series have indicated the majority of mixed martial arts athletes engage in rapid weight loss, there is a lack of officially collected data from sanctioning organizations describing its prevalence. The present investigation represents a summary of the data collected between December 2015 and January 2018 by the California State Athletic Commission. In total, 512 professional mixed martial artists (455 males and 57 females) were included. Of these, 503 (98%) athletes gained body mass between weigh-in and their bouts. Total RWG between weigh-in and competition was 5.5 ± 2.5 kg, corresponding to an 8.1% ± 3.6% body mass increase. Total RWG was 5.6 ± 2.5 kg (8.1% ± 3.6%) for males and 4.5 ± 2.3 kg (8.0% ± 3.8%) for females. More than one quarter of men and one third of women gained >10% body mass between weigh-in and competition. Athletes from leading international promotions gained more absolute, but not relative, body mass than those from regional promotions. Our findings indicate RWG is nearly ubiquitous in professional , with a similar prevalence in male and female athletes. Trends based on promotion suggest a larger magnitude of RWG in presumably more experienced and/or successful mixed martial artists from leading international promotions.


Sports ◽  
2019 ◽  
Vol 7 (9) ◽  
pp. 206 ◽  
Author(s):  
John Connor ◽  
Brendan Egan

Rapid weight loss (RWL) is frequently practiced in weight category sports, including Mixed Martial Arts (MMA). The aim of the present study was to describe self-reported methods of RWL in a sample of competitive MMA athletes comprising of both amateur and professional fighters. The previously-validated Rapid Weight Loss Questionnaire, with the addition of questions on water loading and hot salt baths, was completed anonymously online by athletes (n = 30; all male, n = 15/15 professional/amateur) from MMA clubs around Dublin, Ireland. All but one (97%) of the athletes surveyed lost weight in order to compete, with the average weight loss being 7.9% ± 3.1% of habitual body mass. The RWL score (mean ± SD) for this sample was 37.9 ± 9.6, and a tendency for higher [6.0 (95%CI; −1.1, 13.1) (p = 0.093; d = 0.64)] RWL scores for professional (40.8 ± 8.9) compared to amateur (34.8 ± 9.6) athletes was observed. Frequencies of “always” or “sometimes” were reported as 90% for water loading, 76% for hot salt baths and 55% for 24 h of fasting. Fellow fighters (41%) and coaches/mentors (38%) were “very influential” on RWL practices of these athletes, with doctors (67%), dietitians (41%), and physical trainers (37%) said to be “not influential”. RWL is highly prevalent in MMA across both amateur and professional athletes, and RWL scores are higher than other combat sports. Water loading and hot salt baths are amongst the most commonly used methods of RWL despite little research on these methods for body mass reduction or effects on performance in weight category sports.


2019 ◽  
Vol 3 (Supplement_1) ◽  
Author(s):  
David Benton ◽  
Alecia Cousins ◽  
Hayley Young

Abstract Objectives Reviews consistently find that a loss of about 2% of body mass was needed before either athletic or psychological functioning is disrupted. However, although it is usually assumed that the minor changes in hydration status, that occur during normal life, do not impact on performance, experimentally the topic has been virtually ignored. The impact of everyday variations in hydration was therefore examined. Methods 168 subjects were randomly allocated to drinking water, or not drinking, and in addition consume capsules containing either 300 mg of sodium chloride or a placebo. Subjects were monitored over a three-hour period, during which urine osmolality, loss of body mass and urine production were monitored. Repeatedly subjects reported their mood. Results Subjects came having consumed their normal diet, without any restriction on fluid intake: on average 0.5% body mass was lost during the study. The major finding was that the hydration status on arrival had a greater influence, than subsequent fluid intake and changes in osmolality during the study. With ratings of being agreeable rather than hostile, those with lower baseline osmolality who drank water had better mood than if baseline osmolality was high. As another example, the mood of those who did not drink water only declined during the study when baseline osmolality was high rather than low. With measures of being composed rather than anxious, and being confidence rather than unsure, those who had lower baseline osmolality had a better mood, irrespective of whether water was consumed. Thus, baseline osmolality had an impact greater than drink induced changes in osmolality. Traditionally the normal range of urine osmolality has been said to be 200–800 mOsmoles/kg, yet the critical point at which the response to fluid intake changed was 600 mOsmoles/kg: 61% had a baseline osmolality over 600 and 38% over 800 mOsmoles/kg. Conclusions Some individuals are in a state of dehydration that adversely influences mood; a state not reversed by acute fluid consumption. The pattern of consumption associated with mild-dehydration and its functional consequences needs to be established. Funding Sources There was no funding external other than provided by ** University.


2013 ◽  
Vol 38 (6) ◽  
pp. 621-625 ◽  
Author(s):  
Vahur Ööpik ◽  
Saima Timpmann ◽  
Andres Burk ◽  
Innar Hannus

We assessed the urinary indexes of hydration status of Greco-Roman wrestlers in an authentic precompetition situation at the time of official weigh-in (OWI). A total of 51 of 89 wrestlers competing in the Estonian Championship in 2009 donated a urine sample. Questionnaire responses revealed that 27 wrestlers (body mass losers (BMLs)) reduced body mass before the competition, whereas 24 wrestlers (those who do not lose body mass (n-BMLs)) did not. In 42 wrestlers, values of urine specific gravity ≥1.020 and urine osmolality ≥700 mOsmol·kg−1 revealed a hypohydrated status. The prevalence of hypohydration in the BMLs (96%) was higher than in the n-BMLs (67%) (χ2 = 7.68; p < 0.05). The prevalence of serious hypohydration (urine specific gravity >1.030) was 5.3 times greater (χ2 = 8.32; p < 0.05) in the BMLs than in the n-BMLs. In the BMLs, the extent of body mass gain during the 16-h recovery (2.5 ± 1.2 kg) was associated (r = 0.764; p < 0.05) with self-reported precompetition body mass loss (4.3 ± 2.0 kg) and exceeded the body mass gain observed in the n-BMLs (0.7 ± 1.2 kg; p < 0.05). We conclude that hypohydration is prevalent among Greco-Roman wrestlers at the time of OWI. The prevalence of hypohydration and serious hypohydration is especially high among wrestlers who are accustomed to reducing body mass before competition. These results suggest that an effective rehydration strategy is needed for Olympic-style wrestlers, and that changes in wrestling rules should be considered to reduce the prevalence of harmful body mass management behaviours.


2018 ◽  
Vol 13 (10) ◽  
pp. 1371-1377 ◽  
Author(s):  
Jose Morales ◽  
Carla Ubasart ◽  
Mónica Solana-Tramunt ◽  
Israel Villarrasa-Sapiña ◽  
Luis-Millán González ◽  
...  

Balance, reaction time, and strength are key factors affecting judo performance. Although ample research has been done examining potential strength changes caused by weight loss prior to competition, changes in balance and reaction time have been overlooked. Purpose: To examine the effects of rapid and progressive weight loss (RWL and PWL) on balance, reaction time, and strength in a group of elite judo athletes. Methods: A total of 38 female and male judo athletes (age = 20.6 [2.6] y) completed balance, reaction-time, and strength assessments 1 wk prior to an official weigh-in (pretest) and immediately after the weigh-in (posttest). The athletes were divided into 3 groups, 1 control group who maintained regular training and eating habits, 1 experimental group who engaged in PWL (<3% reductions in body mass), and a second experimental group who used RWL techniques (>3% reductions in body mass). Results: The RWL group showed significant decreases (P < .05) in balance performance (ellipse area: 4.83 [0.87] vs 6.31 [1.39] mm2 with eyes closed; mean mediolateral velocity: 2.07 [0.2] vs 2.52 [0.45] mm·s−1 with eyes closed; and mean anteroposterior velocity: 2.25 [0.20] vs 2.51 [0.32] mm·s−1 with eyes open and 2.44 [0.26] vs 3.06 [0.56] mm·s−1 with eyes closed) and reaction time (0.38 [0.04] vs 0.42 [0.06] s) with no changes in strength from pretesting to posttesting. The athletes in the PWL and control groups maintained performance in all variables. Conclusion: These findings demonstrate negative effects on perceptual motor-skill performance in judo athletes engaging in RWL strategies prior to competition.


2020 ◽  
pp. 2000454
Author(s):  
Jin Hwa Song ◽  
Bong Seong Kim ◽  
Nakwon Kwak ◽  
Kyung-do Han ◽  
Jae-Joon Yim

The incidence and prevalence of nontuberculous mycobacterial pulmonary disease (NTM-PD) have been increasing worldwide. The risk of NTM-PD may be higher in undernourished populations. We tried to elucidate the impact of body mass index (BMI) and its change on development of NTM-PD in this study.We performed a retrospective cohort study including South Koreans age >40 years who underwent biennial National Health Insurance System (NHIS) health checkups in both 2005 and 2009 or 2006 and 2010. We monitored eligible individuals from the study initiation date (NHIS health checkup date on 2009 or 2010) until the diagnosis of NTM-PD or December 31, 2017. Enrolled individuals were classified based on BMI at initiation date. We compared NTM-PD incidence per 100 000 person-years by BMI group as well as by BMI change by calculating hazard ratio (HR).A total of 5 670 229 individuals were included in the final analysis. Compared with the BMI <18.5 kg·m−2 group, the incidence of NTM-PD gradually decreased with increased BMI: adjusted HR (aHR) 0.38 (95% confidence interval [CI] 0.35–0.42) for BMI 18.5–22.9, 0.17 (0.15–0.19) for BMI 23–24.9, 0.1 (0.09–0.11) for BMI 25–29.9, and 0.01 (0.07–0.13) for BMI ≥30. A BMI decrease of ≥1 kg/m2 over 4 years increased the incidence of NTM-PD (aHR 1.08, 95% CI 1.01–1.16) whereas a BMI increase of ≥1 decreased the NTM-PD incidence (0.77, 95% CI 0.71–0.83).In conclusion, BMI was inversely related to development of NTM-PD and weight loss increased the risk of NTM-PD.


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