Daniel A. Judelson

Prevalence of body art (body piercing and tattooing) in university undergraduates and incidence of medical complications.

OBJECTIVES To survey the prevalence of body art (body piercing and tattooing) in university undergraduate students and to determine the incidence of medical complications from these procedures. SUBJECTS AND METHODS Between February and May 2001, students were offered the opportunity to complete an anonymous, voluntary survey at the beginning of class or organizational meetings. The survey instrument requested information concerning body piercing and tattooing (current or removed) by body site, age, sex, height, weight, body mass index, undergraduate class, athletic status, and the occurrence of medical complications. RESULTS Four hundred fifty-four (94.4%) of 481 students completed the survey (14.7% of total campus enrollment). The prevalence of body piercing was 51%, and that of tattooing was 23%. The chi2 analysis showed female students were more likely to be pierced than males (P=.002); there was no significant difference in the prevalence of tattooing by sex. Male athletes were more likely to be tattooed than male nonathletes (P=.02). No relationships were shown between piercing/tattooing and age or measures of body somatotype. The incidence of medical complications of piercing was 17%, and these complications included bleeding, tissue trauma, and bacterial infections. Pierced navels were particularly prone to infection. There were no reported medical complications from tattooing. Eighteen percent of piercings (58/315) and 4% of tattoos (6/149) had been removed. CONCLUSIONS Body art is prevalent among undergraduate university students, and there is a significant incidence of medical complications among students with piercing. Male athletes were significantly more likely to be tattooed than male nonathletes.

Hydration and Muscular Performance Does Fluid Balance Affect Strength, Power and High-Intensity Endurance?

Significant scientific evidence documents the deleterious effects of hypohydration (reduced total body water) on endurance exercise performance; however, the influence of hypohydration on muscular strength, power and high-intensity endurance (maximal activities lasting >30 seconds but <2 minutes) is poorly understood due to the inconsistent results produced by previous investigations. Several subtle methodological choices that exacerbate or attenuate the apparent effects of hypohydration explain much of this variability. After accounting for these factors, hypohydration appears to consistently attenuate strength (by ≈2%), power (by ≈3%) and high-intensity endurance (by ∼10%), suggesting alterations in total body water affect some aspect of force generation. Unfortunately, the relationships between performance decrement and crucial variables such as mode, degree and rate of water loss remain unclear due to a lack of suitably uninfluenced data. The physiological demands of strength, power and high-intensity endurance couple with a lack of scientific support to argue against previous hypotheses that suggest alterations in cardiovascular, metabolic and/or buffering function represent the performance-reducing mechanism of hypohydration. On the other hand, hypohydration might directly affect some component of the neuromuscular system, but this possibility awaits thorough evaluation. A critical review of the available literature suggests hypohydration limits strength, power and highintensity endurance and, therefore, is an important factor to consider when attempting to maximise muscular performance in athletic, military and industrial settings.

Comparison of energy-restricted very low-carbohydrate and low-fat diets on weight loss and body composition in overweight men and women

ObjectiveTo compare the effects of isocaloric, energy-restricted very low-carbohydrate ketogenic (VLCK) and low-fat (LF) diets on weight loss, body composition, trunk fat mass, and resting energy expenditure (REE) in overweight/obese men and women.DesignRandomized, balanced, two diet period clinical intervention study. Subjects were prescribed two energy-restricted (-500 kcal/day) diets: a VLCK diet with a goal to decrease carbohydrate levels below 10% of energy and induce ketosis and a LF diet with a goal similar to national recommendations (%carbohydrate:fat:protein = ~60:25:15%).Subjects15 healthy, overweight/obese men (mean ± s.e.m.: age 33.2 ± 2.9 y, body mass 109.1 ± 4.6 kg, body mass index 34.1 ± 1.1 kg/m2) and 13 premenopausal women (age 34.0 ± 2.4 y, body mass 76.3 ± 3.6 kg, body mass index 29.6 ± 1.1 kg/m2).MeasurementsWeight loss, body composition, trunk fat (by dual-energy X-ray absorptiometry), and resting energy expenditure (REE) were determined at baseline and after each diet intervention. Data were analyzed for between group differences considering the first diet phase only and within group differences considering the response to both diets within each person.ResultsActual nutrient intakes from food records during the VLCK (%carbohydrate:fat:protein = ~9:63:28%) and the LF (~58:22:20%) were significantly different. Dietary energy was restricted, but was slightly higher during the VLCK (1855 kcal/day) compared to the LF (1562 kcal/day) diet for men. Both between and within group comparisons revealed a distinct advantage of a VLCK over a LF diet for weight loss, total fat loss, and trunk fat loss for men (despite significantly greater energy intake). The majority of women also responded more favorably to the VLCK diet, especially in terms of trunk fat loss. The greater reduction in trunk fat was not merely due to the greater total fat loss, because the ratio of trunk fat/total fat was also significantly reduced during the VLCK diet in men and women. Absolute REE (kcal/day) was decreased with both diets as expected, but REE expressed relative to body mass (kcal/kg), was better maintained on the VLCK diet for men only. Individual responses clearly show the majority of men and women experience greater weight and fat loss on a VLCK than a LF diet.ConclusionThis study shows a clear benefit of a VLCK over LF diet for short-term body weight and fat loss, especially in men. A preferential loss of fat in the trunk region with a VLCK diet is novel and potentially clinically significant but requires further validation. These data provide additional support for the concept of metabolic advantage with diets representing extremes in macronutrient distribution.

Caffeine use in sports: considerations for the athlete.

The ergogenic effects of caffeine on athletic performance have been shown in many studies, and its broad range of metabolic, hormonal, and physiologic effects has been recorded, as this review of the literature shows. However, few caffeine studies have been published to include cognitive and physiologic considerations for the athlete. The following practical recommendations consider the global effects of caffeine on the body: Lower doses can be as effective as higher doses during exercise performance without any negative coincidence; after a period of cessation, restarting caffeine intake at a low amount before performance can provide the same ergogenic effects as acute intake; caffeine can be taken gradually at low doses to avoid tolerance during the course of 3 or 4 days, just before intense training to sustain exercise intensity; and caffeine can improve cognitive aspects of performance, such as concentration, when an athlete has not slept well. Athletes and coaches also must consider how a persons body size, age, gender, previous use, level of tolerance, and the dose itself all influence the ergogenic effects of caffeine on sports performance.

Effect of hydration state on resistance exercise-induced endocrine markers of anabolism, catabolism, and metabolism

Hypohydration (decreased total body water) exacerbates the catabolic hormonal response to endurance exercise with unclear effects on anabolic hormones. Limited research exists that evaluates the effect of hypohydration on endocrine responses to resistance exercise; this work merits attention as the acute postexercise hormonal environment potently modulates resistance training adaptations. The purpose of this study was to examine the effect of hydration state on the endocrine and metabolic responses to resistance exercise. Seven healthy resistance-trained men (age = 23 +/- 4 yr, body mass = 87.8 +/- 6.8 kg, body fat = 11.5 +/- 5.2%) completed three identical resistance exercise bouts in different hydration states: euhydrated (EU), hypohydrated by approximately 2.5% body mass (HY25), and hypohydrated by approximately 5.0% body mass (HY50). Investigators manipulated hydration status via controlled water deprivation and exercise-heat stress. Cortisol, epinephrine, norepinephrine, testosterone, growth hormone, insulin-like growth factor-I, insulin, glucose, lactate, glycerol, and free fatty acids were measured during euhydrated rest, immediately preceding resistance exercise, immediately postexercise, and during 60 min of recovery. Body mass decreased 0.2 +/- 0.4, 2.4 +/- 0.4, and 4.8 +/- 0.4% during EU, HY25, and HY50, respectively, supported by humoral and urinary changes that clearly indicated subjects achieved three distinct hydration states. Hypohydration significantly 1) increased circulating concentrations of cortisol and norepinephrine, 2) attenuated the testosterone response to exercise, and 3) altered carbohydrate and lipid metabolism. These results suggest that hypohydration can modify the hormonal and metabolic response to resistance exercise, influencing the postexercise circulatory milieu.

High-affinity growth hormone binding protein and acute heavy resistance exercise

PURPOSE The purpose of this investigation was to examine the influence of resistance training on circulating concentrations of growth hormone binding protein (GHBP) in response to acute heavy resistance exercise. METHODS Using a cross-sectional experimental design, a group of resistance-trained men (RT, N=9, 7.9+/-1.3 yr resistance training experience) and a group of untrained men (UT, N=10) performed an acute heavy resistance exercise protocol (AHREP) consisting of 6 sets of 10 repetition maximum parallel squats. Blood samples were obtained 72 h before exercise, immediately before exercise, and 0, 15, 30, 45, and 60 min after exercise. RESULTS Significant increases (P<0.05) in GHBP, immunoreactive growth hormone (iGH), and IGF-1 were observed in both subject groups after AHREP. There were no differences (P>0.05) between groups in GHBP at rest or after AHREP. However, RT exhibited a significantly greater iGH response to AHREP than UT subjects, and significantly higher IGF-1 values at rest and after exercise. Significant positive correlations were found between GHBP and BMI, body fat, and leptin in both groups. A significant positive correlation also was observed between resting leptin and GHBP values in UT but not RT subjects. CONCLUSIONS In summary, these data indicate that resistance training does not increase blood GHBP. Nevertheless, the increases observed with IGF-1 concentrations in the resistance-trained subjects do suggest an apparent adaptation with the regulation of this hormone. If there was in fact an increase in GH sensitivity and GH receptor expression at the liver that was not detected by blood GHBP in this study, it may be possible that factors contributing to the circulating concentration of GHBP other than hepatocytes (e.g., leptin and adipocytes) may serve to mask training-induced increases in circulating GHBP of a hepatic origin, thus masking any detectable increase in GH receptor expression.

INFLUENCE OF RECOVERY DURATION AFTER A POTENTIATING STIMULUS ON MUSCULAR POWER IN RECREATIONALLY TRAINED INDIVIDUALS

Jo, E, Judelson, DA, Brown, LE, Coburn, JW, and Dabbs, NC. Influence of recovery duration after a potentiating stimulus on muscular power in recreationally trained individuals. J Strength Cond Res 24(2): 343-347, 2010-Research examining postactivation potentiation (PAP) in recreationally trained individuals (RTI) shows mixed results. Because the balance of PAP and fatigue after heavy-load exercise influences performance outcomes, recovery duration after the stimulus might explain inconsistent results noted in RTI. The purpose of this study was to investigate the effect of recovery duration after a potentiating stimulus on muscular power in RTI. Twelve healthy RTI males (age = 23 ± 1 yr, height = 174.6 ± 2.5 cm, mass = 86.3 ± 6.6 kg, 1 repetition maximum [1RM]:mass = 1.4 ± 0.1, body fat = 15.1 ± 2.5 %) minimally possessing 1 year of back squat experience participated. A control session assessed baseline measures on a 30-second Wingate Test. During experimental sessions, subjects performed a back squat exercise (1 set of 5 repetitions at 85% 1RM), rested for 5, 10, 15, or 20 minutes, and performed the Wingate Test. No significant differences existed among control and experimental conditions in all outcome variables; however, maximal values (regardless of rest duration) for absolute peak power (APpwr) (+7.1%), relative peak power (RPpwr) (+7.1%), and fatigue index (FI) (+8.9%) significantly differed from respective control values. The rest duration eliciting maximal PAP significantly correlated (r = −0.771) with relative 1RM. Although recovery duration failed to influence performance after a heavy-load exercise in RTI, discrepancies in individual strength might have influenced the time subjects potentiated. These results suggest stronger subjects might potentiate with less rest after a stimulus (5-10 min), whereas weaker subjects require longer rest durations (15-20 min).

Body composition and physical performance during a National Collegiate Athletic Association Division I men's soccer season.

The purpose of this study was to examine changes in body composition (BC) and physical performance tests (PT) resulting from a competitive season in soccer. Twenty-five male collegiate players (age = 19.9 ± 1.3 years; height = 177.6 ± 6.4 cm; body mass = 77.6 ± 8.6 kg, and percentage body fat = 12.8 ± 5.2%) were tested before (PRE) and after (POST) the 2003–2004 National Collegiate Athletic Association season. The following tests were performed: BC (anthropometric and dual energy x-ray absorptiometry measurements), vertical jump (VJ), 9.1-m (9 m) and 36.5-m (36 m) sprint, lower-body power (LP), total body power (TP), and cardiorespiratory endurance (&OV0312;O2max). Training was divided into soccer-specific training: field warm-up drills, practices, games, and additional conditioning sessions. A daily, unplanned, nonlinear periodization model was used to assign session volume and intensity for strength sessions (total repetitions ≤96 and workload was ≥80% of 1 repetition maximum). For the entire team, body mass significantly increased by 1.5 ± 0.4 kg from PRE to POST due to a significant increase in total lean tissue (0.9 ± 0.2 kg). Regionally, lean tissue mass significantly increased in the legs (0.4 ± 0.0 kg) and trunk (0.3 ± 0.1 kg). Physical performance variables were very similar for the entire team at PRE and POST; VJ (cm) = 61.9 ± 7.1 PRE vs. 63.3 ± 8.0 POST, 9.1-m (s) = 1.7 ± 0.1 PRE and POST, 36.5-m (s) = 5.0 ± 0.2 PRE and POST, predicted &OV0312;O2max (ml·kg·min−1)= 59.8 ± 3.3 PRE vs. 60.9 ± 3.4 POST. The only significant improvements across the season were for TP (17.3%) and for LP (10.7%). In conclusion, soccer athletes who begin a season with a high level of fitness can maintain, and in some cases improve, body composition and physical performance from before to after a competitive season. A correct combination of soccer-specific practices and strength and conditioning programs can maintain and develop physical performance, allowing a soccer athlete to perform optimally throughout pre-, in-, and postseason play.

A comparison of muscle activation between a Smith machine and free weight bench press

Schick, EE, Coburn, JW, Brown, LE, Judelson, DA, Khamoui, AV, Tran, TT, and Uribe, BP. A comparison of muscle activation between a Smith machine and free weight bench press. J Strength Cond Res 24(3): 779-784, 2010-The bench press exercise exists in multiple forms including the machine and free weight bench press. It is not clear though how each mode differs in its effect on muscle activation. The purpose of this study was to compare muscle activation of the anterior deltoid, medial deltoid, and pectoralis major during a Smith machine and free weight bench press at lower (70% 1 repetition maximum [1RM]) and higher (90% 1RM) intensities. Normalized electromyography amplitude values were used during the concentric phase of the bench press to compare muscle activity between a free weight and Smith machine bench press. Participants were classified as either experienced or inexperienced bench pressers. Two testing sessions were used, each of which entailed either all free weight or all Smith machine testing. In each testing session, each participants 1RM was established followed by 2 repetitions at 70% of 1RM and 2 repetitions at 90% of 1RM. Results indicated greater activation of the medial deltoid on the free weight bench press than on the Smith machine bench press. Also, there was greater muscle activation at the 90% 1RM load than at the 70% 1RM load. The results of this study suggest that strength coaches should consider choosing the free weight bench press over the Smith machine bench press because of its potential for greater upper-body muscular development.

Heat Acclimatization and Hydration Status of American Football Players During Initial Summer Workouts

This investigation evaluated the new National Collegiate Athletic Association model of heat acclimatization for football players using physiological, psychological, fluid balance, anthropometric, and nutritional variables. Eleven football players (20 ± 1 year, 1.88 ± 0.05 m, and 115.36 ± 18.85 kg) from a Division I football team were observed for the first 8 days of preseason practices. Measurements such as heart rate and gastrointestinal temperature (TGI) via telemetric sensor were taken before, 3 times during, and after practice daily. An average 1.39-kg (1.2%) decrease of body mass occurred from prepractice to postpractice (p ≤ 0.01). Consistent with mild body mass losses, urinary indices of hydration status (i.e., color, specific gravity, and osmolality) indicated mild fluid deficits. A significant increase (p ≤ 0.05) from pre-to postpractice was observed in urine color and urine specific gravity, but chronic hypohydration over the 8 days was not noted. The Environmental Symptoms Questionnaire (ESQ) postpractice score was significantly higher (p ≤ 0.05) than the prepractice score was, but averages did not differ across practice days. There was no difference in postpractice TGI measurements across days (p ≤ 0.05). Heart rate, TGI, and ESQ measurements indicated that football players experienced gradual heat acclimatization and enhanced heat tolerance, despite progressive increases of exercise variables, clothing, and environmental stressors.