Body Composition of Women's Ice Hockey Players: Comparison of Estimates Using Skinfolds and iDXA.

Gilenstam, K and Geithner, CA. Body composition of women's ice hockey players: comparison of estimates using skinfolds and iDXA. J Strength Cond Res 33(9): 2496-2502, 2019-The purpose of this study was to compare percent fat (% fat) estimates from anthropometric equations using skinfolds (SKF) in women's ice hockey players with estimates obtained from Lunar iDXA. Data were collected on 19 elite female Swedish hockey players (mean age ± SD = 18.4 ± 2.4 years). Four SKF (triceps, abdominal, suprailiac, and thigh) were measured within 2 hours of iDXA assessments. The % fat estimates from iDXA and 4 anthropometric equations were compared using paired t tests, and a 1-way analysis of variance was used to compare % fat estimates from the anthropometric equations. Bland-Altman analyses were used to assess agreement between % fat estimates from SKF and iDXA. The significance level was set a priori at p ≤ 0.05. The % fat estimates from anthropometric equations were significantly lower than those from iDXA (mean ± SD: 26.85 ± 4.93%, p = 0.000). Bland-Altman analyses indicated mean differences of -7.96 to -10.13 percentage points between anthropometric equations and iDXA. Estimates of % fat from anthropometric equations (range: 16.72-18.89%) were within the range reported in earlier studies using the sum of 7 SKF. Thus, SKF offer a reasonable alternative to iDXA for this population but result in underestimates of % fat relative to iDXA. Strength and conditioning coaches should use the same body composition assessment method consistently, and interpret the results with caution, as they are estimates and not true values.

Doing peer review and receiving feedback: impact on scientific literacy and writing skills.

Doing peer review has been effectively implemented to help students develop critical reading and writing skills; however, its application in Human Physiology programs is limited. The purpose of the present study was to determine the impact of peer review on Human Physiology majors' perceptions of their scientific literacy and writing skills. Students enrolled in the Scientific Writing course completed multiple writing assignments, including three revisions after receiving peer and instructor feedback. Students self-assessed their knowledge, skills, and attitudes related to science and writing in pre- and postcourse surveys (n = 26 with complete data). Seven survey items related to scientific literacy and writing skills impacted by peer review were selected for analysis. Scores on these survey items were summed to form a composite self-rating score. Responses to two questions regarding the most useful learning activities were submitted to frequency analysis. Mean postcourse scores for individual survey items and composite self-rating scores were significantly higher than precourse means (P < 0.05). Peer review was the most frequently noted among 21 learning activities for increasing scientific literacy and in the top 5 for improving writing skills. In conclusion, peer review is an effective teaching/learning approach for improving undergraduate Human Physiology majors' knowledge, skills, and attitudes regarding science and scientific writing.

Growth in peak aerobic power during adolescence.

PURPOSE: To model the growth of peak aerobic power during adolescence in both sexes followed longitudinally from 10 to 18 yr. METHODS: Peak aerobic power (peak VO2) was measured annually during a maximal treadmill test with the Bruce protocol. Height and weight were measured semiannually. The Preece-Baines Model I growth function was used to fit curves to data for individuals with >/= six observations for peak aerobic power to estimate age at peak velocity (PV) for peak VO2 (age at PVPVO2), PVPVO2 (L x min(-1) x yr(-1)), and value at PVPVO2 (L x min(-1)) for each individual. Curves were successfully fitted for 83 individuals (48 males, 35 females). The model was also fitted to individual data for height and weight to estimate ages at peak height velocity (PHV) and peak weight velocity (PWV). Age at PVPVO2 was compared with ages at PHV and PWV. Pearson correlation coefficients were calculated between ages at PV and PV for peak VO2, height, and weight. RESULTS: Mean ages at PVPVO2 are 12.3 +/- 1.2 yr for females and 14.1 +/- 1.2 yr for males. Peak VO2 increases in both sexes throughout adolescence, with males having higher values than females at all ages. Age at PVPVO2 occurs nearly coincident with PHV and before PWV in both sexes. Correlation coefficients among ages at PHV, PWV, and PVPVO2 suggest a general maturity factor for body size and aerobic power. CONCLUSION: Growth in peak VO2 exhibits a clear growth spurt in both sexes during adolescence. The growth spurt occurs earlier in females but is of greater magnitude in males.

Adolescent spurts in body dimensions: Average and modal sequences.

The sequence of growth spurts in 11 body dimensions was examined in 101 Polish adolescents, 52 males and 49 females, followed longitudinally from 11-18 years. The dimensions included weight; stature; symphyseal height; biacromial and bicristal breadths; and arm, forearm, chest, thigh and calf circumferences. Upper segment length was estimated as stature minus symphyseal height. Measurements were taken quarterly from 11-14 years, and annually or less frequently thereafter. Growth curves were fitted to individual longitudinal observations using kernel regression to derive estimates of ages at peak velocity (PV) and peak velocities. Within each sex, mean ages at PV were used to define the average sequence, while the most frequently observed sequence of PVs in individuals was used to define the modal sequence. Average and modal sequences differed, the latter probably reflecting individual variability in timing. The spurt in the estimate of leg length (symphyseal height) occurred prior to that for stature in males (first in the sequence) and was nearly coincident with that for stature in females (second in the sequence by 0.01 years). The timing of spurts in other dimensions within each sex was more variable in both average and modal sequences. Am. J. Hum. Biol. 11:287-295, 1999. Copyright 1999 Wiley-Liss, Inc.

Physical and performance differences among forwards, defensemen, and goalies in elite women's ice hockey.

Positional differences have been examined in women's basketball, field hockey, netball, and volleyball, but not in elite women's ice hockey. Our purpose was to describe and compare physical, fitness, and skating performance characteristics of forwards (F), defensemen (D), and goalies (G). Subjects were 112 University of Alberta women players (21.4 +/- 2.9 years of age). A full anthropometric battery was conducted on each player. Heath-Carter anthropometric somatotypes were calculated. Percent body fat (%fat) was estimated from both general and population-specific equations. Subjects performed off-ice fitness tests (vertical jump, 40-yd dash, Leger test for predicting .V(O2)max) and on-ice fitness (Modified 3-Repeat Sprint Skate Test-MRSS, blood lactate after sprint test) and skating performance tests (6.10-m acceleration test, Cornering S-Turn Agility Test). Descriptive statistics and multivariate analyses of variance were run using SPSS (Version 10.0) for the MacIntosh, with a significance level set a priori at p < 0.05. Significant positional differences were found for bicristal breadths (D > G, F > G); relaxed arm circumference (D > F, G > F); supraspinale and biceps skinfolds (G > D, G > F); and endomorphy (G > F). Significant differences among positions were also found for the MRSS (G > D > F) and agility tests (G > D, G > F). D tended to have the most robust build overall. F were leaner than D and G, and their smaller relaxed arm circumference measurements most likely reflect less subcutaneous fat on the upper arm. F had greater anaerobic power than D, followed by G, and they tended to have greater aerobic capacity. F and D were more agile than G. Performance demands appear to be position specific. F need to be the most versatile and fit because of a greater amount and variety of work performed both during practices and games; their required degrees of versatility and fitness are followed by those required of D and G.