Evaluation of the Physical Activity and Public Health Course for Practitioners

Purpose: From 1996 to 2013, a 6-day Physical Activity and Public Health Course for Practitioners has been offered yearly in the United States. An evaluation was conducted to assess the impact of the course on building public health capacity for physical activity and on shaping the physical activity and public health careers of fellows since taking the courses. Method: An evaluation quantified time that fellows spent in different course offerings and surveyed fellows. Results: From 1996 to 2012, 410 fellows attended the course, and in 2013, 186 participated in the Web-based survey (56% response rate). The number of fellows attending the course ranged from 15 to 33 yearly. From 1996 to 2012, the course averaged 38 hr of instructional time that included topics on interventions and environment/policy work to increase physical activity, program evaluation, public health research, and health disparities. The course included consultations, collaborative work, and field-based experiences. Fellows who participated in the survey agreed that the course had a positive impact on the physical activity research or practice work they did (98%), met their expectations (96%), helped them with research/practice collaborations with other physical activity professionals (96%), assisted them in conducting higher-quality interventions/programs (95%), helped increase their professional networking in the field (93%), and had a positive impact on other work they did (91%). Following the course, 66% and 56% had further contact with faculty and other fellows, respectively. Conclusion: The Physical Activity and Public Health Course for Practitioners made important contributions toward building the capacity of physical activity and public health practitioners.     

Altitude and wind effects on long jump performance with particular reference to the world record established by Bob Beamon

An analysis of long jump performance, including both the approach and aerial phases, is applied to Bob Beamon's legendary leap at the Mexico City Olympic Games of 1968. It is shown that the combined effects of altitude and wind assistance yielded an increment in the length of the jump of about 31 cm, compared to a corresponding jump at sea level under still air conditions. The main factor is shown to be the increased sprinting speed attained under favourable conditions of wind and altitude.     

Iron status in Winter Olympic sports

Iron status was surveyed amongst 92 Winter Olympic sport athletes from Nordic and Alpine skiing, figure and speed skating and ice hockey. Haemoglobin and serum ferritin values were obtained by physicians as part of a monitoring programme, since iron deficiency would have an adverse effect on maximal performance. Four (7%) of 56 men were anaemic (Hb < 14.0 gdl^‐1) and three (8%) of 36 women had haemoglobin values less than 12.0 gdl^‐1. Nine men (16%) and 14 women (39%) had prelatent iron deficiency (serum ferritin < 30 ng ml^‐1). Ice hockey had the lowest while Nordic skiing had the highest incidence of sub‐optimal iron status. A total of 50% of Nordic women skiers had prelatent iron deficiency and 7% were anaemic. An equal percentage of women speed skaters were low in serum ferritin as well. Only one of 20 male ice hockey players was low in serum ferritin. These results suggest there would be value in instituting screening procedures for iron status in Winter Olympic Sports.     

Two critical psychological components of ski racing: Fun and feelings

The concepts of having fun and being aware of feeling states are presented as two critical factors in ski racing. First, the positive motivational characteristics of ‘fun’ are outlined. It is suggested that fun is not only a concept for young athletes but elite ones as well. Preliminary data based on a questionnaire, completed by the United States Alpine Ski Team and approximately 150 ski coaches, are presented. Second, the discussion on feelings refers to the mental programming of tactile sensations and determining one's emotional arousal (feeling state) prior to, and during, competition. Practical suggestions are made with regard to the psychological states and their effects on ski racing.     

Urea production during prolonged swimming

Male interscholastic swimmers (n = 8) completed a 4572 m training swim in 62 ±1.1 min (x ± s.e.) with terminal heart rate and blood lactate of 152 ± 6 beats min^‐1 and 6.9±0.89 mM, respectively. Sweat rate (0.48±0.0951. h^‐1) was lower than similar intensity cycling (1.5±0.13 1. h^‐1) or running (1.1 ± 0.14 l.h^‐1). Post‐swim serum urea N (11.6±0.71 mM) was elevated (P<0.05) vs pre‐swim (4.6±0.39 mM). Post‐swim urine volume (860±75 ml 24 h^‐1) was reduced (P<0.07) and resulted in an elevated (P<0.05), but delayed (24–84 h), post‐exercise urea N excretion. Although the reduced urine and sweat production during the swim undoubtedly contributed to the elevated serum urea, there must be another explanation because together they could only account for 38% of the observed increase. On the basis of the magnitude of serum urea increase, it appears that the swim caused an increase in urea production (amino acid oxidation). The failure to observe larger increases in urinary urea during recovery indicates that either urea excretion following exercise continues for prolonged periods of time (>48 h) or another significant mode of nitrogen excretion exists.     

Skating

Technical evaluation in the sport of figure skating is characterized by a subjective marking system. Figure skating judges are responsible for quickly and accurately discerning the quality of technical elements as well as assigning a score to the overall aesthetic appearance of a performance. Traditionally, overall placement marks are assigned for the entire performance; however, the landing of a jump is widely acknowledged as one of the most critical elements of a skater's program. Therefore, our aims were to identify the biomechanical variables that contribute to technical success in executing landings and to establish whether landings rated as biomechanically optimal are also awarded high technical merit scores by judges. Ten nationally ranked competitive figure skaters were asked to execute on‐ice, double and triple revolution jumps and to try to land the jumps void of technical faults within a calibrated space. Data were collected at 60 Hz using standard three‐dimensional videography. Data reduction was done using the APAS system (Ariel Dynamics Inc). Concurrently, videotapes were viewed and evaluated by 42 accredited judges to determine the perceived technical quality of the landing performances. Judges were asked to evaluate the landing phase of each jump against a landing criteria document. A comparative criteria model was developed to facilitate an assessment of excellence in landing performances through both empirical and subjective analyses. Results of these analyses were twofold: a biomechanical profile of on‐ice landings was obtained, and on‐ice jump landing strategies rated by empirical evaluations were in agreement with judge's perceptions of the same performances.     

Relative shank to thigh length is associated with different mechanisms of power production during elite male ergometer rowing

The effect of anthropometric differences in shank to thigh length ratio upon timing and magnitude of joint power production during the drive phase of the rowing stroke was investigated in 14 elite male rowers. Rowers were tested on the RowPerfect ergometer which was instrumented at the handle and foot stretcher to measure force generation, and a nine segment inverse dynamics model used to calculate the rower's joint and overall power production. Rowers were divided into two groups according to relative shank thigh ratio. Time to half lumbar power generation was significantly earlier in shorter shank rowers (p = 0.028) compared to longer shank rowers, who showed no lumbar power generation during the same period of the drive phase. Rowers with a relatively shorter shank demonstrated earlier lumbar power generation during the drive phase resulting from restricted rotation of the pelvic segment requiring increased lumbar extension in these rowers. Earlier lumbar power generation and extension did not appear to directly affect performance measures of the short shank group, and so can be attributed to a technical adaptation developed to maximise rowing performance.