Tailored advice on exercise - Does it make a difference?

Objectives: A controlled trial to compare the effectiveness of verbal advice from a family physician (FP) combined with either standard or tailored written information on physical activity in increasing the levels of physical activity in sedentary patients. Design: Sedentary patients (n = 763) were recruited through ten family practices and allocated to a control group or one of two intervention groups, Brief advice on physical activity was given by the FP during the consultation and either a standard or tailored pamphlet was mailed to the home address of patients assigned to the intervention groups within two days of their visit to the FP. Results: The response to follow-up, via a postal survey at one, six, and twelve months after the index consultation was 70%, 60%, and 57%, respectively. Treating all nonresponders as sedentary, the results revealed that although more tailored subjects reported some physical activity at each follow-up compared with the standard group, these differences were not significant, Furthermore, there was no significant difference in movement across the stages of readiness to exercise at follow-up between subjects in the tailored group who received material targeting their current stage (precontemplation or contemplation) and the standard group who received generic material that addressed both stages. Conclusion: These findings do not concur with the results from previous research in the areas of nutrition and smoking cessation where additional benefits were seen with a tailored intervention. Future research on the application of the principles of tailoring to the promotion of physical activity should focus on identifying which, if any, physical, social, psychological or environmental variables should be addressed to produce improved outcomes over and above the effects of well designed generic materials. (C) 1999 American Journal of Preventive Medicine

Traditional and modified exits following freestyle tumble turns by skilled swimmers

Dolphin kicking and flutter kicking off the wall were compared via videography and force platform following a tumble turn by elite age-group swimmers. Subjects comprised eight males (n=8) of mean height, 178.9±7.03cm; mass, 70.8±6.59kg; and age, 16.88±2.42 years; and five females (n=5) of mean height 169.5+3.30cm; mass, 61.0±5.56kg; and age 15.0±1.22 years. Subjects swam 4 x 50m (2 dolphin turn, 2 flutter turn) freestyle sprints in a 25m pool. A repeated measures ANOVA using selected variables as covariates was conducted with 5m out-time as the dependent variable. No significant differences were observed between the dolphin kick and flutter kick turns for 5m out-time. The time spent kicking during the dolphin trials was significantly greater (63.3%) than the time-to-5m compared with the flutter trials (45.6%). Deceleration was less during the dolphin kick than the flutter kick trials and velocity above that of free swimming was maintained longer when using the dolphin kick technique. No significant advantage was gained from either kick technique following a tumble turn

A comparison and analysis of traditional and modified freestyle tumble turns by age-group swimmers

This study examined the use of a modified freestyle tumble turn which used a dolphin kick off the wall compared with the traditional flutter kick tumble turn. Twenty male and 17 female age-group swimmers (mean age 11.3 ± 1.3yrs; height 153.6 ± 9.7cm; weight 42.5 ± 8.3kg) performed 25m dolphin and flutter kick time trials and 4x50m (2 dolphin turns, 2 flutter turns) maximal freestyle efforts in a short course pool with push starts on a 6min departure interval. Underwater video and wall turn force data were collected

Technical note: The use of subject derived scale factors for one-camera 2D analysis in underwater swimming

This technical note describes a comparison of relative errors in one-camera 2D underwater motion analysis when using two different control structure methods for calibrating video images. Eleven male and six female participants performed underwater kicking swim trials. A reference structure of known length and each swimmer's actual (land measured) thigh length were each used to calibrate the movement space from which digitised thigh lengths were calculated from each trial. For each trial, mean thigh lengths calculated using the two methods were then compared to actual thigh length for each swimmer and the differences recorded. Mean differences between actual and computed thigh lengths for the two methods were shown to be similar. However, the spread of mean differences was much less when the actual thigh length was used for calibration. This result strongly supports the use of thigh length as a more accurate method of calibration for one-camera 2D underwater motion analysis