Prevention of weight gain in young adults through a seminar-based intervention program.

OBJECTIVE: Prevention would be the ideal public health strategy to face the current obesity epidemic. Adoption of healthy lifestyles during the first years of college or university could prevent the onset of weight gain associated with this period of acquired independence and eventually decrease the incidence of obesity. DESIGN: Randomized-controlled trial over a period of 2 years. The subjects received an educational/behavioral intervention (small group seminars) designed to help maintain a healthy lifestyle or no specific intervention (control group). SUBJECTS: One-hundred and fifteen non-obese freshmen in a Faculty of Medicine. MEASUREMENTS: Anthropometric measurements, physical activity level, fitness level, food intake and lipid profile were recorded at predetermined intervals. RESULTS: The control group gained weight, whereas the intervention group lost a slight amount of weight over 2 years. The difference between the two groups was 1.3 kg at the end of the follow-up, the trend of weight gain differing between the two groups during the 2-year intervention period (P=0.04). There was no detectable difference in fitness, physical activity level or total caloric intake between the two groups during follow-up. However, plasma triglyceride levels increased in the control group and decreased in the intervention group (P=0.04). CONCLUSION: In this randomized-controlled trial, a small-group seminar educational/behavioral intervention successfully prevents weight gain in normal weight young healthy university students. Such small absolute changes in body composition and lipid profile, if maintained over a prolonged period, could result in significant long-term health benefits for the general population.

The anterior cruciate ligament: a review of recent concepts.

The anterior cruciate ligament (ACL) consists of a small anteromedial band and a larger posterolateral band. Recent findings have shown the ACL to play a major role in the function of the knee joint. The ACL prevents anterior luxation of the tibia, limits tibial rotation, and resists valgus and varus stress to the knee. The most common mechanism of ACL injury involves hyperextension of the knee with a rotational component. Diagnosis of an ACL lesion consists of an accurate history, clinical tests and often, arthroscopic investigation. Treatment of an ACL injury may consist solely of a rehabilitation program, may involve surgical intervention, or a combination of the two. Many surgical procedures both intra-articular and extra-articular, have been used in the past. The most successful approach at this time appears to be a combination of intra-articular and extra-articular procedures. A contemporary trend in rehabilitation following surgery is the use of graduated stages of treatment beginning immediately postsurgery and continuing through to full return to activity. J Orthop Sports Phys Ther 1986;8(3):110-122.

Influence of exercise training on tissue chromium concentrations in the rat.

This study reports on the effects of exercise training on the chromium concentrations in the heart, liver, kidney, and gastrocnemius muscle of normal Sprague-Dawley rats. A pair-fed (to the trained rats' intake) and a preexperimental group were also studied in order to control food intake and to ascertain any age-related influence on tissue chromium levels, respectively. Four groups of animals were examined: exercise-trained, pair-fed, preexperimental, and sedentary control. Chromium determination was performed by flameless atomic absorption spectrophotometry. The results from this study show that exercise training increases while pair-feeding and normal aging both decrease chromium levels in tissues. It is suggested that the male Sprague-Dawley rat adapts to exercise training by enhancing tissue levels of chromium or by simply maintaining the high levels of the element found at a younger age.

The bicycle ergometer for muscle power testing.

The force-velocity relationship implies that the faster a contracting muscle is permitted to shorten, the weaker it becomes or the slower a contracting muscle is permitted to shorten, the stronger it becomes until it reaches maximal isometric tension. The relationship is hyperbolic for a denervated muscle but is inverse and linear for functionally innervated muscle groups. When the force of contraction is multiplied by the velocity of contraction, a power production curve is obtained. The purposes of the study were to examine the force-velocity relationship on a standard bicycle ergometer, to deduce a power-velocity curve, to compare the results of young men and women and to see if the measures were reproducible. Fifty-eight young men and women volunteered for the study. Testing consisted of pedalling as quickly as possible for five seconds at resistance settings from 2 to 7-kg. In order to evaluate the reproducibility of the scores, retesting was done one hour later. It was shown that the relationship between the resistance settings and the number of revolutions completed by the male and female subjects was inverse and linear. The higher the resistance setting was, the larger was the difference in the scores of the young men and women. When a power curve was derived for each group, a peak power was only identified in the female subjects and this was encountered at a 5-kg resistance setting. The scores obtained at a resistance setting of 5 and 7 kg for female and male subjects respectively showed the best reproducibility. The bicycle ergometer may not be used as an alternative but as a complementary tool to an isokinetic dynamometer.