Vicarious Experience to Affect Physical Activity in Women: A Randomized Control Trial.

People compare themselves to others for self-evaluation, practical information, and motivation for healthy behaviors. The effect of active peer models on comparative thinking is unknown. The purpose of this 12-week, randomized, two-group pilot study was to evaluate the effect of a workplace peer modeling intervention on self-efficacy, motivation, and comparative thinking. The attention control group (ACG; n = 24) received general health information. The intervention group (n = 26) met with active peer models, received an exercise prescription and information. No significant group by time interaction effects were found. Comparisons on ability (how well am I doing), opinions (what should I think or believe), future self (think about my future), and modeling (be like someone else) all increased in the intervention group (n = 21) but decreased in the ACG (n = 22). Active peer models may support physical activity behavior change through specific lines of comparative thinking.

Perceptions of a Peer Modeling Workplace Physical Activity Intervention for Women.

A workplace physical activity (PA) study tested a novel use of peers to deliver the intervention. Peer models provided vicarious experience for living physically active lifestyles to a group of inactive women. The purpose of this study was to describe participants' perceptions of the peer modeling intervention. Nine women from the intervention group ( n = 26) participated in a 90-minute focus group. Qualitative description using thematic analysis was used to identify themes from the focus group transcript. Two themes about the intervention were "I am left wanting more" and "focus on food." Two themes about the peer models were "real people" and "it is doable." Focus group participants perceived the peer modeling PA intervention favorably; however, they desired more attention to healthy eating and more time with peer models. Replication of the study accounting for themes identified by focus group participants is needed to strengthen the peer modeling intervention.

Feasibility and Effect of a Peer Modeling Workplace Physical Activity Intervention for Women.

Most working women do not meet current guidelines for physical activity (PA). A 12-week pilot study tested a workplace, peer modeling PA intervention. Inactive female employees from a health system were randomized to an attention control group (ACG; n = 26) or an intervention group (IG; n = 26). The ACG received health information. The IG participated in six group sessions with an active peer model and received an exercise prescription and PA information. Pre and post measures were PA (ActiGraph), Estimated VO2max (cycle ergometer), resting heart rate (HR), glucose and lipids, and cardiovascular risk. Using hierarchical linear modeling, no significant group by time effects were found. Although PA increased in both groups, F( df = 1) = 11.4, p = .002, the IG had greater improvements in fitness (VO2max, HR) and cardiovascular risk (total cholesterol, triglyceride, low density lipoprotein [LDL], calculated risk score) compared with ACG. Results support repeating this intervention in a fully powered study.

Concurrent Validity of Wearable Activity Trackers Under Free-Living Conditions.

Brooke, SM, An, H-S, Kang, S-K, Noble, JM, Berg, KE, and Lee, J-M. Concurrent validity of wearable activity trackers under free-living conditions. J Strength Cond Res 31(4): 1097-1106, 2017-The purpose of this study is to evaluate the concurrent validity of wearable activity trackers in energy expenditure (EE) and sleep period time (SPT) under free-living conditions. Ninety-five (28.5 ± 9.8 years) healthy men (n = 34) and women (n = 61) participated in this study. The total EE and SPT were measured using 8 monitors: Nike+ FuelBand SE (NFB), Garmin VivoFit (VF), Misfit Shine (MF), Fitbit Flex (FF), Jawbone UP (JU), Polar Loop (PL), Fitbit Charge HR (FC), and SenseWear Armband Mini (SWA) (criterion measures: SWA for EE and a sleep log for SPT). The mean absolute percent error (MAPE) for EE was 13.0, 15.2, 15.5, 16.1, 16.2, 22.8, and 24.5% for PL, MF, FF, NFB, FC, JU, and VF, respectively. Mean absolute percent errors were calculated for SPT to be 4.0, 8.8, 10.2, 11.5, 12.9, 13.6, 17.5, and 21.61% for VF, FF, JU, FC, MF, SWA laying down, PL, and SWA, respectively. Concurrent validity was examined using equivalence testing on EE (equivalence zone: 2,889.7-3,531.9 kcal); 2 trackers fell short of falling in the zone: PL (2,714.4-3,164.8 kcal) and FC (2,473.8-3,066.5 kcal). For SPT (equivalence zone: 420.6-514.0 minutes), several monitors fell in the zone: PL (448.3-485.6 minutes), MS (442.8-492.2 minutes), and FF (427.7-486.7 minutes). This study suggests that the PL and FC provide a reasonable estimate of EE under free-living conditions. The PL, FC, and MF were the most valid monitors used for measuring SPT.

Comparison of V[Combining Dot Above]O2peak and Achievement of V[Combining Dot Above]O2peak Criteria in Three Modes of Exercise in Female Triathletes.

Snoza, CT, Berg, KE, and Slivka, DR. Comparison of V[Combining Dot Above]O2peak and achievement of V[Combining Dot Above]O2peak criteria in three modes of exercise in female triathletes. J Strength Cond Res 30(10): 2816-2822, 2016-The purpose of this study was to compare peak aerobic capacity in female triathletes in 3 modes of exercise: treadmill, cycle, and arm ergometer. A second purpose was to determine the extent that physiologic criteria for achieving V[Combining Dot Above]O2peak were reached in each mode of exercise. Six criteria were examined: V[Combining Dot Above]O2 plateau, heart rate (HR), blood lactate concentration (BLC), respiratory exchange ratio, oxygen saturation, and rating of perceived exertion (RPE). Twelve recreational level female triathletes completed maximal tests on the treadmill, stationary bike, and arm ergometer. Results indicated V[Combining Dot Above]O2peak (ml·kg·min) is highest on a treadmill (46.8 ± 2.1), intermediate in cycling (40.7 ± 5.0), and lowest in arm ergometry (28.2 ± 3.3) with mean differences being significant (p ≤ 0.05). Blood lactate concentration and RPE criteria were met by the highest number of subjects across the 3 modes of testing while the HR criterion was not achieved in any participant in arm ergometry and only 2 in cycling. It was concluded that in moderately trained recreational level triathletes, V[Combining Dot Above]O2peak is highest in running and lowest in arm ergometry. Criteria for achieving V[Combining Dot Above]O2peak most frequently were blood lactate level and RPE. Coaches and researchers should appreciate that V[Combining Dot Above]O2peak values of moderately trained triathletes differ considerably in contrast to elite triathletes and tend to be highest on the treadmill and lowest in arm ergometry. Also, criteria used to determine achievement of V[Combining Dot Above]O2peak should be carefully selected and seem to be best achieved using BLC and RPE.

Grunting in tennis increases ball velocity but not oxygen cost.

Grunting is widely used by professional tennis players, but no research has been done to verify enhanced performance with grunting. Therefore, the purpose of this study was to determine if grunting enhanced ball velocity in groundstrokes and secondly, to determine if grunting increased the physiological cost of hitting (VO2, HR, VE/VO2, and RPE). Participants were 10 members of the men's (n = 5) and women's (n = 5) tennis teams at a Division I university who had just completed their indoor competitive season. Two hitting sessions were used as players repetitively hit forehand and backhand shots while either grunting or not grunting. Each hitting session consisted of five 2-minute periods with a 1-minute break in between each period. Ball velocity was measured with a radar gun. During each hitting session, players wore a portable metabolic measuring unit. HR was monitored using a Polar monitor, and RPE was assessed using Borg's 6-20 scale. Grunting increased ball velocity (kph) 3.8% compared with non-grunting condition (p < 0.034) with the mean ± SD being 83.4 ± 0.6.1 and 80.3 ± 0.8.7, respectively. The physiological responses (VO2, HR, VE/VO2, and RPE) for the 2 hitting conditions were not significantly different for any variable. When averaged across both hitting conditions, HR over the 5-time periods was higher in periods 3-5 than period (p < 0.018) 1, whereas VE/VO2 and RPE were greater in periods 2-5 than period 1 (p = 0.001). RPE significantly increased over time with periods 2-5 being greater than period 1 (p = 0.001). It was concluded that grunting increased ball velocity without increasing VO2 or VE/VO2 or RPE in comparison with not grunting. It may be worthwhile for players and coaches in tennis and other sports to experiment with grunting to determine possible improvement in performance.

Interleukin-6 and delayed onset muscle soreness do not vary during the menstrual cycle.

The purpose of this study was to determine if a difference in interleukin-6 (IL-6) and delayed onset muscles soreness (DOMS) exists in two different phases of the menstrual cycle. Nine runners performed one 75-min high-intensity interval running session during the early follicular (EF) phase and once during the midluteal (ML) phase of the menstrual cycle. Estrogen and progesterone levels were significantly reduced in the EF phase when compared to the ML phase. IL-6 levels increased from pre- to postexercise in the EF and ML phases (p < .001). There was no relationship between the IL-6 level and DOMS. The results suggest that menstruating female runners need not vary training throughout the month to reduce DOMS.

Pacing pattern and physiological responses to a 5-minute maximal exercise bout.

The purpose of this study was to describe the pacing strategy of experienced cyclists in a 5-minute maximal exercise bout and to describe selected physiological responses associated with this effort. Six experienced and well-trained competitive cyclists (five males, one female) with a mean (+/-SD) age, height, and mass of 27.0 +/- 4.77 years, 174.7 +/- 8.57 cm, and 71.0 +/- 6.45 kg, performed a 5-minute maximal exercise bout in a laboratory on a racing cycle. Subjects were free to determine their work rate throughout. During exercise, data were collected for work rate, heart rate (HR), [latin capital V with dot above]O2, electromyography of the rectus femoris and vastus lateralis, oxygen saturation, and rating of perceived exertion. All six subjects selected a pacing strategy characterized by a surge in work rate in the first minute followed by a gradual decline until the last minute, when a sprint to the end occurred. Values for HR, respiratory exchange ratio, and blood lactate concentration (182.8 +/- 2.8 bpm, 1.08 +/- 0.07, and 15.5 +/- 2.1 mmol x L-1, respectively) indicated that [latin capital V with dot above]O2 (3.6 +/- 0.4 L x min-1) was close to or at maximum from minutes 2 to 5. Oxygen saturation dropped continuously across time, reaching <94% in the last minute, and rating of perceived exertion was 19.5 +/- 0.8. Electromyographic activity of the rectus femoris and vastus lateralis was not significantly related to work rate during the bout (p > 0.05). It is concluded that work rate or pace is uneven in an all-out, 5-minute exercise bout in experienced cyclists, yet the physiological responses are near maximal in minutes 2-5. Cyclists seem to pace themselves in a common pattern in short-term stochastic exercise bouts. The possible benefits of including some stochastic exercise in the training programs of athletes might be worthy of examination.

Relationship between measures of body size and composition and velocity of lactate threshold.

The purpose of this investigation was to explore the relationship between velocity of lactate threshold (vLT) and various measures of body mass and composition: mass, lean mass, fat mass, percent body fat (% fat), and body surface area (BSA). We hypothesized that mass would be inversely related to vLT, and that differences in measures of body mass and composition would account for a significant amount of variability in vLT. A total of 21 healthy male runners served as subjects. Body composition was assessed by hydrostatic weighing. A significant negative relationship (r = -0.759, p < or = 0.01) was between body mass and vLT. The coefficient of determination between vLT and body mass indicated that nearly 58% of the variability in vLT was explained by body mass in these subjects. Significant relationships were also between vLT and BSA (r = -0.72, p < or = 0.01), fat mass (r = -0.70, p < or = 0.01), % fat (r = -0.59, p < or = 0.01), and lean mass (r = -0.41, p < or = 0.05). Linear regression yielded the following model: y = 369.48 - 1.7343 (X), where y = predicted vLT (m.min(-1)) and X = body mass (kilograms) (SEE = 15.45). Velocity of lactate threshold was significantly inversely related with body mass in a group of male runners. The calculated coefficient of determination suggests that nearly 58% of the variability in vLT was explained by body mass. The present data suggest consideration of categorizing participants in 'road runs' by body mass to equate competition, as is done in other sports (e.g., weightlifting).

Comparison of physical and performance characteristics of NCAA Division I football players: 1987 and 2000.

The purpose of this study was to compare normative data from present Division I National Collegiate Athletic Association football teams to those from 1987. Players were divided into 8 positions for comparisons: quarterbacks (QB), running backs (RB), receivers (WR), tight ends (TE), offensive linemen (OL), defensive linemen (DL), linebackers (LB), and defensive backs (DB). Comparisons included height, body mass, bench press and squat strength, vertical jump, vertical jump power, 40-yd-dash speed, and body composition. Independent t-tests were used to analyze the data with level of significance set at p < 0.01. Significant differences (p < 0.01) were found in 50 of 88 comparisons. From 1987 until 2000, Division I college football players in general have become bigger, stronger, faster, and more powerful. Further research is warranted to investigate if these trends will continue.