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Eric R. Helms, Caryn Zinn, David S. Rowlands and Scott R. Brown

Caloric restriction occurs when athletes attempt to reduce body fat or make weight. There is evidence that protein needs increase when athletes restrict calories or have low body fat.

Purpose:

The aims of this review were to evaluate the effects of dietary protein on body composition in energy-restricted resistance-trained athletes and to provide protein recommendations for these athletes.

Methods:

Database searches were performed from earliest record to July 2013 using the terms protein, and intake, or diet, and weight, or train, or restrict, or energy, or strength, and athlete. Studies (N = 6) needed to use adult (≥ 18 yrs), energy-restricted, resistance-trained (> 6 months) humans of lower body fat (males ≤ 23% and females ≤ 35%) performing resistance training. Protein intake, fat free mass (FFM) and body fat had to be reported.

Results:

Body fat percentage decreased (0.5–6.6%) in all study groups (N = 13) and FFM decreased (0.3–2.7kg) in nine of 13. Six groups gained, did not lose, or lost nonsignificant amounts of FFM. Five out of these six groups were among the highest in body fat, lowest in caloric restriction, or underwent novel resistance training stimuli. However, the one group that was not high in body fat that underwent substantial caloric restriction, without novel training stimuli, consumed the highest protein intake out of all the groups in this review (2.5–2.6g/kg).

Conclusions:

Protein needs for energy-restricted resistance-trained athletes are likely 2.3–3.1g/kg of FFM scaled upwards with severity of caloric restriction and leanness.

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Mohamad S. Motevalli, Vincent J. Dalbo, Reza S. Attarzadeh, Amir Rashidlamir, Patrick S. Tucker and Aaron T. Scanlan

Purpose:

To evaluate anthropometric measures and serum markers of myostatin-pathway activity after different weight-reduction protocols in wrestlers.

Methods:

Subjects were randomly assigned to a gradual-weight-reduction (GWR) or rapid-weight-reduction (RWR) group. Food logs were collected for the duration of the study. Anthropometric measurements and serum samples were collected after an 8-h fast at baseline and after the weight-reduction intervention. Subjects reduced body mass by 4%. The GWR group restricted calories over 12 d, while the RWR group restricted calories over 2 d. A series of 2 × 5 repeated-measures (RM) ANOVAs was conducted to examine differences in nutrient consumption, while separate 2 × 2 RM ANOVAs were conducted to examine differences in anthropometric measures and serum markers. When applicable, Tukey post hoc comparisons were conducted. Significance for all tests was set at P < .05.

Results:

There were no between-groups differences for any anthropometric measure (P > .05). Subjects in both groups experienced a significant reduction in body mass, fat mass, lean mass, and percent body fat (P < .05). There were no between-groups differences in serum markers of myostatin-pathway activity (P > .05), but subjects in the RWR condition experienced a significant increase in serum myostatin (P < .01), a decrease in follistatin (P < .01), and an increase in myostatin-to-follistatin ratio (P < .001).

Conclusion:

Although there were no between-groups differences for any outcome variables, the serum myostatin-to-follistatin ratio was significantly increased in the RWR group, possibly signaling the early stages of skeletal-muscle catabolism.

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Andreas M. Kasper, Ben Crighton, Carl Langan-Evans, Philip Riley, Asheesh Sharma, Graeme L. Close and James P. Morton

The aim of the present case study was to quantify the physiological and metabolic impact of extreme weight cutting by an elite male mixed martial arts athlete. Throughout an 8-week period, we obtained regular assessments of body composition, resting metabolic rate, peak oxygen uptake, and blood clinical chemistry to assess endocrine status, lipid profiles, hydration, and kidney function. The athlete adhered to a “phased” weight loss plan consisting of 7 weeks of reduced energy (ranging from 1,300 to 1,900 kcal/day) intake (Phase 1), 5 days of water loading with 8 L/day for 4 days followed by 250 ml on Day 5 (Phase 2), 20 hr of fasting and dehydration (Phase 3), and 32 hr of rehydration and refueling prior to competition (Phase 4). Body mass declined by 18.1% (80.2 to 65.7 kg) corresponding to changes of 4.4, 2.8, and 7.3 kg in Phases 1, 2, and 3, respectively. We observed clear indices of relative energy deficiency, as evidenced by reduced resting metabolic rate (−331 kcal), inability to complete performance tests, alterations to endocrine hormones (testosterone: <3 nmol/L), and hypercholesterolemia (>6 mmol/L). Moreover, severe dehydration (reducing body mass by 9.3%) in the final 24 hr prior to weigh-in-induced hypernatremia (plasma sodium: 148 mmol/L) and acute kidney injury (serum creatinine: 177 μmol/L). These data, therefore, support publicized reports of the harmful (and potentially fatal) effects of extreme weight cutting in mixed martial arts athletes and represent a call for action to governing bodies to safeguard the welfare of mixed martial arts athletes.

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George T. Baker III and George R. Martin

Aging is characterized by numerous physical, physiological, biochemical, and molecular changes. The rates at which aging processes occur are highly variable among individuals and are thought to be governed by both environmental and genetic factors. Lifestyle factors such as exercise, dietary, and smoking habits have been demonstrated to alter many of the changes usually associated with human aging. However, at present caloric restriction is the only experimental paradigm that has consistently been demonstrated in animal models to extend not only physiological vigor but also life span. The positive effects of exercise on physiological fitness and the reduction in the risks of certain diseases have been well documented. However, its effects on life span are not as clear. This article explores some of the basic mechanisms thought to be involved causally in the processes of aging, and outlines current and potential interventive strategies to retard or ameliorate the rates of decline in physiological function with advancing age.

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Ellen Weissinger, Terry J. Housh, Glen O. Johnson and Sharon A. Evans

Self-reports of weight loss knowledge, attitudes, and methods in a sample of 125 high school wrestlers are described. These responses are compared to perceptions of 88 wrestlers’ parents regarding their son’s weight loss behaviors. Responses to survey questionnaires indicated that wrestlers were highly likely to deliberately lose weight for wrestling and that they most commonly used increased exercise, caloric restriction, and fluid restriction as weight loss techniques. Wrestlers reported use of extreme weight loss techniques (fasting, vomiting, diuretics) in higher proportions than the general adolescent male population, despite their reports of detrimental effects of such methods. Compared to their sons, parents significantly underestimated the use of extreme methods and were more realistic about the potential harmful effects of severe weight loss. Wrestlers and parents alike felt that weight loss is overemphasized in wrestling competition. These findings indicate a need for improved adult monitoring of high school wrestling programs.

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Mathieu L. Maltais, Karine Perreault, Alexandre Courchesne-Loyer, Jean-Christophe Lagacé, Razieh Barsalani and Isabelle J. Dionne

The decrease in resting energy expenditure (REE) and fat oxidation with aging is associated with an increase in fat mass (FM), and both could be prevented by exercise such as resistance training. Dairy consumption has also been shown to promote FM loss in different subpopulations and to be positively associated with fat oxidation. Therefore, we sought to determine whether resistance exercise combined with dairy supplementation could have an additive impact on FM and energy metabolism, especially in individuals with a deficit in muscle mass. Twenty-six older overweight sarcopenic men (65 ± 5 years old) were recruited for the study. They participated in 4 months of resistance exercise and were randomized into three groups for postexercise shakes (control, dairy, and nondairy isocaloric and isoprotein supplement with 375 ml and ~280 calories per shake). Body composition was measured by dual X-ray absorptiometry and REE by indirect calorimetry. Fasting glucose, insulin, leptin, inflammatory profile, and blood lipid profile were also measured. Significant decreases were observed with FM only in the dairy supplement group; no changes were observed for any other variables. To conclude, FM may decrease without changes in metabolic parameters during resistance training and dairy supplementation with no caloric restriction without having any impact on metabolic properties. More studies are warranted to explain this significant decrease in FM.

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Joan Khoo, Subbiah Dhamodaran, Dan-Dan Chen, Siew-Yoon Yap, Richard Yuan-Tud Chen and Roger Ho-Heng Tian

The adipokines chemerin and adiponectin are reciprocally related in the pathogenesis of insulin resistance and inflammation in obesity. Weight loss increases adiponectin and reduces chemerin, insulin resistance, and inflammation, but the effects of caloric restriction and physical activity are difficult to separate in combined lifestyle modification. We compared effects of diet- or exercise-induced weight loss on chemerin, adiponectin, insulin resistance, and inflammation in obese men. Eighty abdominally obese Asian men (body mass index [BMI] ≥ 30 kg/m2, waist circumference [WC] ≥ 90 cm, mean age 42.6 years) were randomized to reduce daily intake by ~500 kilocalories (n = 40) or perform moderate-intensity aerobic and resistance exercise (200–300 min/week) (n = 40) to increase energy expenditure by a similar amount for 24 weeks. The diet and exercise groups had similar decreases in energy deficit (−456 ± 338 vs. −455 ± 315 kcal/day), weight (−3.6 ± 3.4 vs. −3.3 ± 4.6 kg), and WC (−3.4 ± 4.4 vs. −3.6 ± 3.2 cm). The exercise group demonstrated greater reductions in fat mass (−3.9 ± 3.5 vs. −2.7 ± 5.3 kg), serum chemerin (−9.7 ± 11.1 vs. −4.3 ± 12.4 ng/ml), the inflammatory marker high-sensitivity C-reactive protein (−2.11 ± 3.13 vs. −1.49 ± 3.08 mg/L), and insulin resistance as measured by homeostatic model assessment (−2.45 ± 1.88 vs. −1.38 ± 3.77). Serum adiponectin increased only in the exercise group. Exercise-induced fat mass loss was more effective than dieting for improving adipokine profile, insulin resistance, and systemic inflammation in obese men, underscoring metabolic benefits of increased physical activity.

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Sang-Ho Lee, Steven D. Scott, Elizabeth J. Pekas, Jeong-Gi Lee and Song-Young Park

improving cholesterol and oxidative stress that occur from sports that require excessive weight change and high-intensity exercise have not been examined. Therefore, the purpose of this study was to examine the effects of octacosanol supplementation during rapid weight loss through caloric restriction with

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Amy J. Hector and Stuart M. Phillips

dietary caloric restriction for the reduction of body fat, which may be advantageous in a variety of sports including aesthetic and weight class sports to improve power-to-weight ratios as well as to improve overall athletic performance ( Sundgot-Borgen & Garthe, 2011 ). However, there can be an

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Todd Miller, Stephanie Mull, Alan Albert Aragon, James Krieger and Brad Jon Schoenfeld

of RT and AE had a greater impact on improving body composition than diet alone. In a study specific to resistance training, Bouchard, Soucy, Senechal, Dionne, and Brochu ( 2009 ) compared the effects of caloric restriction (CR), resistance training (RT), or a combination of the two (CR + RT) in a