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I-Min Lee, Kathleen Y. Wolin, Sarah E. Freeman, Jacob Sattlemair and Howard D. Sesso

Background:

The number of cancer survivors is increasing rapidly; however, little is known about whether engaging in physical activity after a cancer diagnosis is associated with lower mortality rates in men.

Methods:

We conducted a prospective cohort study of 1021 men (mean age, 71.3 years) who were diagnosed with cancer (other than nonmelanoma skin cancer). Men reported their physical activities (walking, stair climbing, and participation in sports and recreational activities) on questionnaires in 1988, a median of 6 years after their cancer diagnosis. Physical activity was updated in 1993 and men were followed until 2008, with mortality follow-up > 99% complete, during which 777 men died (337 from cancer, 190 from cardiovascular disease).

Results:

In multivariate analyses, the relative risks for all-cause mortality associated with expending < 2100, 2100–4199, 4200–8399, 8400–12,599, and ≥ 12,600 kJ/week in physical activity were 1.00 (referent), 0.77, 0.74, 0.76, and 0.52, respectively (P-trend < 0.0001). Higher levels of physical activity also were associated with lower rates of death from cancer and cardiovascular disease (P-trend = 0.01 and 0.002, respectively).

Conclusions:

Engaging in physical activity after cancer diagnosis is associated with better survival among men.

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Roy J. Shephard

The pediatric sports physician faces an epidemic of obesity. A preliminary triage of individual patients can be based on the body mass index (BMI). The 80th and 95th percentiles of age-specific BMI suggest overweight and obesity, respectively; the diagnosis is confirmed by measurements of triceps and subscapular skinfolds. Over the last twenty years, the proportions of overweight and obese children have increased in both indigenous populations and most developed societies. The increase in body fat content seems to be associated with a decline in daily energy expenditure. Immediate health consequences include an increased prevalence of atherosclerotic plaques, hypertension, and an adverse lipid profile; in addition, the resulting poor self-image limits sport participation. Many obese children become obese adults, facing increased risks of cardiovascular and all-cause deaths. A combination of increased lifestyle activities, behavioral modification techniques to reduce sedentary behavior, and an appropriate diet seems to be the most effective approach to both prevention and treatment of obesity. Such initiatives should be supported by quality daily physical education and changes in the urban environment that encourage an active lifestyle.

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Pedro C. Hallal, Kelly Cordeira, Alan G. Knuth, Grégore Iven Mielke and Cesar G. Victora

Background:

One-third of adults worldwide are physically inactive causing over 5.3 million deaths annually. Despite a growing focus on physical activity and health, population-based data on physical activity trends in low- and middle-income countries are still limited. To help fill the gap, this study provides trend data over a 10-year period in Pelotas, a southern Brazilian city.

Methods:

The short version of the International Physical Activity Questionnaire was used to assess the prevalence of physical inactivity in 2002 (n = 3119), 2007 (n = 2969), and 2012 (n = 2868). Levels of inactivity and trends were assessed according to sex, age, schooling, and socioeconomic position (SEP).

Results:

The prevalence of physical inactivity rose from 41.1% (95% CI: 37.4–44.9) in 2002 and 52.0% (95% CI: 49.1–53.8) in 2007 to 54.4% (95% CI: 51.8–56.9) in 2012 (P < .001). Physical inactivity significantly increased in all subgroups except in the highest SEP and 70+ year age subgroups.

Conclusions:

After a sharp increase in the prevalence of physical inactivity from 2002–2007, levels plateaued from 2007–2012. However, it is important to stress that current levels are still unacceptably high, and that efforts must be intensified to reverse the trend.

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Ray Tricker, David L. Cook and Rick McGuire

In recent years drug abuse by college athletes has received greater attention. Because of the recognition of the growing problem of drug use in athletics, the new NCAA drug testing policy, and recent deaths of elite athletes, the sport psychologist should be prepared to deal with this issue. In many college settings the sport psychologist may be expected to provide support with counseling or participate in the development of a drug abuse prevention program for student athletes. Therefore sport psychologists need to closely examine the factors that may predispose athletes toward using drugs, understand the role of prevention, and develop a thorough knowledge of positive, viable alternatives to drugs. This article addresses five important issues that relate to drug abuse in college athletics: (a) why athletes are at risk, (b) athletic leadership and its relationship to substance abuse, (c) the role of the sport psychologist, (d) issues related to the effectiveness of drug education for athletes, and (e) recommendations for athlete drug education programs.

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Priscila M. Nakamura, Grégore I. Mielke, Bernardo L. Horta, Maria Cecília Assunção, Helen Gonçalves, Ana M.B. Menezes, Fernando C. Barros, Ulf Ekelund, Soren Brage, Fernando C. Wehrmeister, Isabel O. Oliveira and Pedro C. Hallal

Background:

Physical inactivity is responsible for 7% of diabetes deaths worldwide, but little is known whether low levels of physical activity (PA) during adolescence increase the risk of diabetes in early adulthood. We evaluated the cross-sectional and longitudinal associations between PA throughout adolescence and HbA1c concentration in early adulthood.

Methods:

HbA1c was measured by high performance liquid chromatography. PA was assessed by self-report at the ages of 11, 15, and 18 years and by accelerometry at the ages of 13 (subsample) and 18 years. The loss percentages of follow up were 12.5% at 11 years, 14.4% at 15 years, and 18.7% at 18 years.

Results:

At 18 years, boys showed higher HbA1c than girls. At age 18 years, accelerometrybased PA at 18 years was inversely related to HbA1c levels in boys. Self-reported leisure-time PA at ages 11, 15, and 18 were unrelated to HbA1c in both genders. PA at 13 years of age was unrelated to HbA1c among both genders. In trajectory analysis, PA and accelerometer PA trajectories were not associated with later HbA1c.

Conclusions:

Objectively measured PA at 18 years was cross-sectionally inversely associated with HbA1c in boys only. No prospective associations were identified.

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Megan L. Keen and Kevin C. Miller

Clinical Scenario:

Exercise performed in hot and humid environments increases core body temperature (TC). If TC exceeds 40.5°C for prolonged periods of time, exertional heat stroke (EHS) may occur. EHS is a leading cause of sudden death in athletes. Mortality and morbidity increase the longer the patient’s TC remains above 40.5°C; thus, it is imperative to initiate cooling as quickly as possible. Acceptable cooling rates in EHS situations are 0.08–0.15°C/min, while ideal cooling rates are above 0.16°C/min. Cooling vests are popular alternatives for cooling hyperthermic adults. Most vests cover the anterior and posterior torso and have varying numbers of pouches for phase-change materials (eg, gel packs); some vests only use circulating water to cool. While cooling vests offer several advantages (eg, portability), studies demonstrating their effectiveness at rapidly reducing TC in EHS scenarios are limited.

Clinical Question:

Are TC cooling rates acceptable (ie, >0.08°C/min) when hyperthermic humans are treated with cooling vests postexercise?

Summary of Findings:

No significant differences in TC cooling rates occurred between cooling vests and no cooling vests. Cooling rates across all studies were ≤0.053°C/min.

Clinical Bottom Line:

Cooling vests do not provide acceptable cooling rates of hyperthermic humans postexercise and should not be used to treat EHS. Instead, EHS patients should be treated with cold-water immersion within 30 min of collapse to avoid central nervous system dysfunction and organ failure.

Strength of Recommendation:

Strong evidence (eg, level 2 studies with PEDro scores ≥5) suggests that cooling vests do not reduce TC quickly and thus should not be used in EHS scenarios.

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Tyler T. Truxton and Kevin C. Miller

Clinical Scenario:

Exertional heat stroke (EHS) is a medical emergency which, if left untreated, can result in death. The standard of care for EHS patients includes confirmation of hyperthermia via rectal temperature (Trec) and then immediate cold-water immersion (CWI). While CWI is the fastest way to reduce Trec, it may be difficult to lower and maintain water bath temperature in the recommended ranges (1.7°C–15°C [35°F–59°F]) because of limited access to ice and/or the bath being exposed to high ambient temperatures for long periods of time. Determining if Trec cooling rates are acceptable (ie, >0.08°C/min) when significantly hyperthermic humans are immersed in temperate water (ie, ≥20°C [68°F]) has applications for how EHS patients are treated in the field.

Clinical Question:

Are Trec cooling rates acceptable (≥0.08°C/min) when significantly hyperthermic humans are immersed in temperate water?

Summary of Findings:

Trec cooling rates of hyperthermic humans immersed in temperate water (≥20°C [68°F]) ranged from 0.06°C/min to 0.19°C/min. The average Trec cooling rate for all examined studies was 0.11±0.06°C/min.

Clinical Bottom Line:

Temperature water immersion (TWI) provides acceptable (ie, >0.08°C/min) Trec cooling rates for hyperthermic humans post-exercise. However, CWI cooling rates are higher and should be used if feasible (eg, access to ice, shaded treatment areas).

Strength of Recommendation:

The majority of evidence (eg, Level 2 studies with PEDro scores ≥5) suggests TWI provides acceptable, though not ideal, Trec cooling. If possible, CWI should be used instead of TWI in EHS scenarios.

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Shannon J. FitzGerald, Carolyn E. Barlow, James B. Kampert, James R. Morrow Jr., Allen W. Jackson and Steven N. Blair

Background:

The beneficial effects of cardiorespiratory fitness on mortality are well known; however, the relation of muscular fitness, specifically muscular strength and endurance, to mortality risk has not been thoroughly examined. The purpose of the current study is to determine if a dose-response relation exists between muscular fitness and mortality after controlling for factors such as age and cardiorespiratory fitness.

Methods:

The study included 9105 men and women, 20–82 years of age, in the Aerobics Center Longitudinal Study who have completed at least one medical examination at the Cooper Clinic in Dallas, TX between 1981 and 1989. The exam included a muscular fitness assessment, based on 1-min sit-up and 1-repetition maximal leg and bench press scores, and a maximal treadmill test. We conducted mortality follow-up through 1996 primarily using the National Death Index, with a total follow-up of 106,046 person-years. All-cause mortality rates were examined across low, moderate, and high muscular fitness strata.

Results:

Mortality was confirmed in 194 of 9105 participants (2.1%). The age- and sex-adjusted mortality rate of those in the lowest muscular fitness category was higher than that of those in the moderate fitness category (26.8 vs. 15.3 per 10,000 person-years, respectively). Those in the high fitness category had a mortality rate of 20.6 per 10,000 person-years. The moderate and high muscular fitness groups had relative risks of 0.64 (95%CI = 0.44–0.93) and 0.80 (95%CI = 0.49–1.31), adjusting for age, health status, body mass index, cigarette smoking, and cardio-respiratory fitness when compared with the low muscular fitness group.

Conclusions:

Mortality rates were lower for individuals with moderate/high muscular fitness compared to individuals with low muscular fitness. These findings warrant further research to confirm the apparent threshold effect between low and moderate/high muscular fitness and all-cause mortality.

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Shane Bilsborough and Neil Mann

Considerable debate has taken place over the safety and validity of increased protein intakes for both weight control and muscle synthesis. The advice to consume diets high in protein by some health professionals, media and popular diet books is given despite a lack of scientific data on the safety of increasing protein consumption. The key issues are the rate at which the gastrointestinal tract can absorb amino acids from dietary proteins (1.3 to 10 g/h) and the liver’s capacity to deaminate proteins and produce urea for excretion of excess nitrogen. The accepted level of protein requirement of 0.8g · kg−1 · d−1 is based on structural requirements and ignores the use of protein for energy metabolism. High protein diets on the other hand advocate excessive levels of protein intake on the order of 200 to 400 g/d, which can equate to levels of approximately 5 g · kg−1 · d−1, which may exceed the liver’s capacity to convert excess nitrogen to urea. Dangers of excessive protein, defined as when protein constitutes > 35% of total energy intake, include hyperaminoacidemia, hyperammonemia, hyperinsulinemia nausea, diarrhea, and even death (the “rabbit starvation syndrome”). The three different measures of defining protein intake, which should be viewed together are: absolute intake (g/d), intake related to body weight (g · kg−1 · d−1) and intake as a fraction of total energy (percent energy). A suggested maximum protein intake based on bodily needs, weight control evidence, and avoiding protein toxicity would be approximately of 25% of energy requirements at approximately 2 to 2.5 g · kg−1 · d−1, corresponding to 176 g protein per day for an 80 kg individual on a 12,000kJ/d diet. This is well below the theoretical maximum safe intake range for an 80 kg person (285 to 365 g/d).

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Kadhiresan R. Murugappan, Michael N. Cocchi, Somnath Bose, Sara E. Neves, Charles H. Cook, Todd Sarge, Shahzad Shaefi and Akiva Leibowitz

affected National Collegiate Athletic Association (NCAA) Division I football players, the risk of exertional death was 37 times higher than in athletes without sickle cell trait ( Harmon et al., 2012 ). The pathophysiologic mechanism remains unclear; however, increased sickling of erythrocytes occurring