PURPOSE:The purpose of this study was to determine the dietary, anthropometric, blood-lipid, and performance patterns of university-level American football players attempting to increase body mass during 8 wk of training.METHODS:Three-day diet records, body composition (DEXA scan), blood lipids, and performance measures were collected in redshirt football players (N = 15, age 18.5 ± 0.6 yr) early season and after 8 wk of in-season training.RESULTS:There was an increase (p < .05) from early-season to postseason testing for reported energy (+45%), carbohydrate (+82%), and protein (+29%) intakes and no change in the intake of fat. Fat intake was 41% of energy at the early-season test and 32% of energy at the postseason test. Increases (p < .05 for all) in performance measures, lean mass (70.5 ± 7.7-71.8 ± 7.7 kg), fat mass (15.9 ± 6.2-17.3 ± 6.8 kg), plasma total cholesterol (193.5 ± 32.4-222.6 ± 40.0 mg/dl), and low-density lipoproteins (LDL; 92.7 ± 32.7-124.5 ± 34.7 mg/dl) were measured. No changes were measured in triglycerides, very-low-density lipoproteins, or high-density lipoproteins.CONCLUSION:Increases in strength, power, speed, total body mass, muscle mass, and fat mass were measured. Cholesterol and LDL levels increased during the study to levels associated with higher risk for cardiovascular disease. It is possible that this is a temporary phenomenon, but it is cause for concern and an indication that dietary education to promote weight gain in a manner less likely to adversely affect the lipid profile is warranted.
Background: Collagen hydrolysate is a nutritional supplement that has been shown to exert an anabolic effect on cartilage tissue. Its administration appears beneficial in patients with osteoarthritis.Objective: To investigate the effect of collagen hydrolysate on activity-related joint pain in athletes who are physically active and have no evidence of joint disease.Design and setting: A prospective, randomized, place bo-controlled, double-blind study was conducted at Penn State University in University Park, Pennsylvania. Parameters including joint pain, mobility, and inflammation were evaluated with the use of a visual analogue scale during a 24-week study phase.Study participants: Between September 2005 and June 2006, 147 subjects who competed on a varsity team or a club sport were recruited. Data from 97 of 147 subjects could be statistically evaluated.Intervention: One hundred and forty-seven subjects (72 male, 75 female) were randomly assigned to two groups: a group (n = 73) receiving 25 mL of a liquid formulation that contained 10 g of collagen hydrolysate (CH-Alpha)* and a group (n = 74) receiving a placebo, which consisted of 25 mL of liquid that contained xanthan.Main outcome measures: The primary efficacy parameter was the change in the visual analogue scales from baseline during the study phase in relation to the parameters referring to pain, mobility, and inflammation.Results: When data from all subjects (n 97) were evaluated, six parameters showed statistically significant changes with the dietary supplement collagen hydrolysate (CH) compared with placebo: joint pain at rest, assessed by the physician (CH vs. placebo (-1.37 +/- 1.78 vs. -0.90 +/- 1.74 (p = 0.025)) and five parameters assessed by study participants: joint pain when walking (-1.11 +/- 1.98 vs. -0.46 +/- 1.63, p = 0.007), joint Pain when standing (-0.97 +/- 1.92 vs. -0.43 +/- 1.74, p = 0.011), joint pain at rest (-0.81 +/- 1.77 vs. -0.39 +/- 1.56, p 0.039), joint pain when carrying objects (-1.45 +/- 2.11 vs. -0.83 +/- 1.71, p = 0.014) and joint pain when lifting (-1.79 +/- 2.11 vs. -1.26 +/- 2.09, p = 0.018). When a subgroup analysis of subjects with knee arthralgia (n = 63) was performed, the difference between the effect of collagen hydrolysate vs. placebo was more pronounced. The parameter joint pain at rest, assessed by the physician, had a statistical significance level of p = 0.001 (-1.67 +/- 1.89 vs. -0.86 +/- 1.77), while the other five parameters based on the participants' assessments were also statistically significant: joint pain when walking (p = 0.003 (-1.38 +/- 2.12 vs. -0.54 +/- 1.65)), joint pain when standing (p = 0.015 (-1.17 +/- 2.06 vs. -0.50 +/- 1.68)), joint pain at rest with (p = 0.021 (-1.01 +/- 1.92 vs. -0.47 +/- 1.63)), joint pain when running a straight line (p 0.027 (-1.50 +/- 1.97 vs. -0.80 +/- 1.66)) and joint pain when changing direction (p = 0.026 (-1.87 +/- 2.18 vs. -1.20 +/- 2.10)).Conclusion: This was the first clinical trial of 24-weeks duration to show improvement of joint pain in athletes who were treated with the dietary supplement collagen hydrolysate. The results of this study have implications for the use of collagen hydrolysate to support joint health and possibly reduce the risk of joint deterioration in a high-risk group. Despite the study's size and limitations, the results suggest that athletes consuming collagen hydrolysate can reduce parameters (such as pain) that have a negative impact on athletic performance. Future studies are needed to support these findings.
Osteoarthritis, a debilitating joint disorder, is the most common form of arthritis in the United States, where it affects an estimated 21 million people. In 2004, the direct and indirect health care costs associated with all forms of arthritis were approximately 86 billion dollars. Joint discomfort from osteoarthritis and other joint disorders may reduce physical activity in individuals experiencing this condition, resulting in energy imbalance and weight gain. Increased weight can exacerbate existing problems, as additional stress on joints stimulates risk of additional joint disorders. Dietitians play a role in preventing or reversing the problem of joint disorders by promoting nutrient-rich diets that support joint health through improvement in cartilage metabolism. In addition, counseling individuals on weight management and active lifestyles are key strategies for the management of joint health.
ACSM Position Stand on the Appropriate Intervention Strategies for Weight Loss and Prevention of Weight Regain for Adults. Med. Sci. Sports Exerc., Vol. 33, No. 12, 2001, pp. 2145-2156. In excess of 55% of adults in the United States are classified as either overweight (body mass index = 25-29.9 kg.m(-2)) or obese (body mass index greater than or equal to 30 kg.m(-2)). To address this significant public health problem, the American College of Sports Medicine recommends that the combination of reductions in energy intake and increases in energy expenditure, through structured exercise and other forms of physical activity, be a component of weight loss intervention programs. An energy deficit of 500-1000 kcal.d(-1) achieved through reductions in total energy intake is recommended. Moreover, it appears that reducing dietary fat intake to < 30% of total energy intake may facilitate weight loss by reducing total energy intake. Although there may be advantages to modifying protein and carbohydrate intake, the optimal doses of these macronutritents for weight loss have not been determined. Significant health benefits can be recognized with participation in a minimum of 150 min (2.5 h) of moderate intensity exercise per week, and overweight and obese adults should progressively increase to this initial exercise goal. However, there may be advantages to progressively increasing exercise to 200-300 min (3.3-5 h) of exercise per week, as recent scientific evidence indicates that this level of exercise facilitates the long-term maintenance of weight loss. The addition of resistance exercise to a weight loss intervention will increase strength and function but may not attenuate the loss of fat-free mass typically observed with reductions in total energy intake and loss of body weight. When medically indicated, pharmacotherapy may be used for weight loss, but pharmacotherapy appears to be most effective when used in combination with modifications of both eating and exercise behaviors. The American College of Sports Medicine recommends that the strategies outlined in this position paper be incorporated into interventions targeting weight loss and the prevention of weight regain for adults.
This study examined how altering text and graphics of a nutrition brochure could affect the ability to remember the content of the message. Two theoretical models were used to guide alterations: dual-coding theory and the communications model. Three brochure formats were tested: the original brochure containing abstract text and abstract graphics, a modified brochure with relatively concrete text and abstract graphics, and a relatively concrete text brochure with concrete graphics. Participants (N = 239 women) were divided into four age groups: 20-30, 40-50, 60-70 and over 70 years. Women were randomly assigned into each of the three experimental brochure formats or a control group. Participants completed recalled materials from the assigned brochures (the no treatment control group did not include a brochure) at two different sessions, 30 days apart. Data were content analyzed and results were compared using analysis of covariance to test differences by age and brochure types. Younger women (20-30 and 40-50 years) recalled more information than women over 60 years. More concrete nutrition education print materials enhanced recall of information presented immediately after reading the material; however, this effect was transient and lasted less than 30 days after a one-time reading. The implications of these data for communicating nutrition messages with print materials are discussed.
Kristine Clark, Ph.D., R.D., FACSM, counsels collegiate athletes from 29 sports teams and is the Director of Sports Nutrition at Penn State University. Dr. Clark is the nutritionist for the U.S. Soccer Federation. A three-time marathon finisher, Dr. Clark currently trains for competitive race walking.
PURPOSEThe purpose of this study was to examine the physiological effects of a weight-loss dietary regimen with or without exercise.METHODSThirty-five overweight men were matched and randomly placed into either a control group (C; N = 6) or one of three dietary groups; a diet-only group (D; N = 8), a diet group that performed aerobic exercise three times per week (DE; N = 11); and a diet group that performed both aerobic and strength training three times per week (DES; N = 10).RESULTSAfter 12 wk, D, DE, and DES demonstrated a similar and significant (P < or = 0.05) reduction in body mass (-9.64, -8.99, and -9.90 kg, respectively) with fat mass comprising 69, 78, and 97% of the total loss in body mass, respectively. The diet-only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (+19.6%) and squat exercise (+32.6%). Absolute peak O2 consumption was significantly elevated in DE (+24.8%) and DES (+15.4%). There were no differences in performance during a 30-s Wingate test for the DE and DES, whereas D demonstrated a significant decline in peak and mean power output. Resting metabolic rate (RMR) (kcal x d(-1)) was not significantly different for any of the groups except for the DE group. There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and high density lipoprotein (HDL) cholesterol for any of the groups. Serum total cholesterol and low density lipoprotein (LDL) cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at week 6 and remained lower at week 12 for D, while triglycerides returned to baseline values for DES.CONCLUSIONSThese data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and maximum oxygen consumption compared with weight-loss induced by diet alone.
To examine the physiological effects of a weight-loss dietary regimen with or without exercise, thirty-five overweight men were matched and randomly placed into either a control group (C; n=6) or one of three dietary groups; a diet only group (D; n=8), a diet group that performed aerobic exercise 3 times per week (DE; n=11); and a diet group that performed both aerobic and strength training 3 times per week (DES;n=10). After 12 wks, D, DE, and DES demonstrated a similar and significant (P≤0.05) reduction in body mass (-9.64, -8.99, and-9.90 kg, respectively) with fat mass comprising 69%, 78%, and 97% of the total loss in body mass, respectively. The diet only group also demonstrated a significant reduction in fat-free mass. Maximum strength, as determined by 1-RM testing in the bench press and squat exercise was significantly increased for DES in both the bench press (19.6%) and squat exercise (32.6%). Absolute peak O2 consumption was significantly elevated in DE (24.8%) and DES(27.4%). There were no significant changes in basal concentrations of serum glucose, BUN, cortisol, testosterone, and HDL cholesterol for any of the groups. Serum total cholesterol and LDL cholesterol were significantly decreased for all dietary groups. Serum triglycerides were significantly reduced for D and DES at Week 6 and remained lower at Week 12 for D, while triglycerides returned to baseline values for DES. These data indicate that a weight-loss dietary regimen in conjunction with aerobic and resistance exercise prevents the normal decline in fat-free mass and muscular power and augments body composition, maximal strength, and peak O2 consumption compared to weight-loss induced by diet alone.
Kris Clark counsels collegiate athletes from 29 sports teams and is the Director of Sports Nutrition at Penn State University. Dr. Clark is the USO (United States Olympic Committee) soccer spokesperson far nutrition and the sports nutritionist for the U.S. women's soccer team and both the U.S. men's and women's field hockey teams. A three-time marathon finisher, Dr. Clark currently trains for competitive race walking.
Objective This study was undertaken to investigate the influence of oral supplementation with creatine monohydrate on muscular performance during repeated sets of high-intensity resistance exercise.Subjects/design Fourteen active men were randomly assigned in a double-blind fashion to either a creatine group (n=7) or a placebo group (n=7). Both groups performed a bench press exercise protocol (5 sets to failure using each subject's predetermined 10-repetition maximum) and a jump squat exercise protocol (5 sets of 10 repetitions using 30% of each subject's 1-repetition maximum squat) on three different occasions (T1, T2, and T3) separated by 6 days.Intervention Before T1, both groups received no supplementation. From T1 to T2, both groups ingested placebo capsules. From T2 to T3, the creatine group ingested 25 g creatine monohydrate per day, and the placebo group ingested an equivalent amount of placebo.Main outcome measures Total repetitions for each set of bench presses and peak power output for each set of jump squats were determined. Other measures included assessment of diet, body mass, skinfold thickness, and preexercise and 5-minute postexercise lactate concentrations.Results Lifting performance was not altered for either exercise protocol after ingestion of the placebos. Creatine supplementation resulted in a significant improvement in peak power output during all 5 sets of jump squats and a significant improvement in repetitions during all 5 sets of bench presses. After creatine supplementation, postexercise lactate concentrations were significantly higher after the bench press but not the jump squat. A significant increase in body mass of 1.4 kg (range= 0.0 to 2.7 kg) was observed after creatine ingestion.Conclusion One week of creatine supplementation (25 g/day) enhances muscular performance during repeated sets of bench press and jump squat exercise.
Thirty-one women (mean age 35.4 +/- 8.5 yr) who were overweight were matched and randomly placed into either a control group (Con; n = 6), a diet-only group (D; n = 8), a diet+aerobic endurance exercise training group (DE; n = 9), or a diet+aerobic endurance exercise training+strength training group (DES; n = 8). After 12 wk, the three dietary groups demonstrated a significant (P </= 0.05) reduction in body mass, %body fat, and fat mass. No differences were observed in the magnitude of loss among groups, in fat-free mass, or in resting metabolic rate. The DE and DES groups increased maximal oxygen consumption, and the DES group demonstrated increases in maximal strength. Weight loss resulted in a similar reduction in total serum cholesterol, low-density lipoprotein cholesterol, and high-density lipoprotein cholesterol among dietary groups. These data indicate that weight loss during moderate caloric restriction is not altered by inclusion of aerobic or aerobic+resistance exercise, but diet in conjunction with training can induce remarkable adaptations in aerobic capacity and muscular strength despite significant reductions in body mass.
The Journal staff talked with six registered dietitians whose expertise was integral to the Olympic Games this summer in Atlanta. They worked in capacities that ranged from developing personal nutrition programs for athletes to directing the medical services at one of the Olympic venues. Each experience was unique, but all of the dietitians displayed pride in their profession and expressed a real joy for sharing The American Dietetic Association's (ADA) mission of promoting optimal nutrition, health, and well-being to the world.