86 research outputs found

    Psychophysiological Tracking of a Female Physique Competitor Through Competition Preparation

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    International Journal of Exercise Science 10(2): 301-311, 2017. Natural physique competitions are based on subjective judgments of how a competitor appears on show day. Prior to competition, there is a prolonged dieting phase referred to as contest preparation. The primary goal is to reduce body fat levels while maintaining skeletal muscle mass. The study tracked the physiological and psychological changes for a 24 year old female preparing for a physique competition. Purpose: The study was conducted to describe the physiological and psychological changes of a female physique competitor who engages in long-term contest preparation. Methods: Diet, body composition, blood work, energy expenditure, mood, and performance were evaluated through contest preparation. Results: The participant lost 10.1kg throughout contest preparation in a strong weekly linear pattern (R2=0.97). Body fat was reduced from 30.45% to 15.85% while fat free mass was maintained. Mood for the participant remained stable until month five, when an observed variation occurred, with performance maintaining. Conclusions: Contest preparation was successful in reducing the body fat in the participant while having a minimum effect on both performance and fat free mass. For athletes looking to lose large amounts of body fat with minimal performance decrements a prolonged diet period with moderate exercise and food restriction can be an effective solution

    Eccentric strain at long muscle length evokes the repeated bout effect.

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    Journal ArticleThe repeated bout effect (RBE) is a phenomenon characterized by less delayed onset muscle soreness (DOMS) and torque deficit after the second of 2 separate eccentric exercise bouts. Previous investigators have reported that shifting of optimum angle after an initial bout of eccentric exercise mediates the RBE. We hypothesized that an RBE for elbow extensor exercise occurs after an initial bout performed at long (starting position of 50 degrees to an end position of 130 degrees) but not short (starting position of 0 degrees to an end position of 80 degrees) muscle length because strain at long length evokes a shifting of the optimum angle to a longer length. Untrained women performed an initial bout at either long or short length (n = 9 per group) followed 1 week later by a repeated bout (RB) through the full ROM (0-130 degrees). Extensor torque and optimum angle was evaluated before, immediately after, and 2 days after each bout. A mechanical transducer depressed on the triceps brachii quantified DOMS. Torque deficits were 3% and 7% after exercise at short vs. long length, respectively. Two days after the RB, torque deficit was 8% and 1% for those previously exercising at short vs. long length (group x bout, p < 0.05). Greater DOMS (N) was observed after exercise at long (16 +/- 3) vs. short (23 +/- 2) length; whereas greater DOMS occurred for the short-length (17 +/- 2) vs. long (26 +/- 3) group after the RB (group x bout, p < 0.05). Optimum angle shifted to a longer length after exercise at long (+10 +/- 4 degrees) vs. short (+1 +/- 3 degrees) length (group x bout, p < 0.05). After the RB, those exercising previously at short length experienced a shift of +15 +/- 4 degrees (main effect, p < 0.05). The findings of this study indicate that the repetitive strain at long but not short muscle length evokes both immediate and sustained shifts in optimum angle to longer lengths, and that this shifting mediates (r(2) = 0.71) the RBE

    Validity of the Bottle Buoyancy Model for Body Fat Determination

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    International Journal of Exercise Science 10(1): 87-96, 2017. We investigated a modification of the bottle buoyancy (BB) method in comparison to single frequency, bioelectric impedance analysis (BIA) as a valid noninvasive method of percent body fat (%BF) determination. Twenty-eight participants (15 men, 13 women), in counterbalanced-order, completed the BB, BIA, and computerized hydrostatic densitometry (HD) methods. We elected to modify the BB method using a 12.15 L container with participants hugging the container in an upright position. Consistency measures of intraclass correlation coefficient (ICC), typical error (TE), coefficient of variation (CV) and total error of measurement (TEM) are reported. Our modification of the BB resulted in less ā€œbobbingā€ than described in the previous method, and took ~5 to 15 min per participant to complete. Group values (%BF) did not differ (p \u3e 0.05) for BB (20.7 Ā± 6.6), BIA (21.0 Ā± 9.7), and HD (20.2 Ā± 7.2). Strong measurement agreement was observed between BB and HD (ICC: 0.95, TE: 1.80 %BF, CV: 10.7%, TEM: 1.77 %BF). Agreement between BIA and HD (ICC: 0.85, TE: 3.35 %BF, CV: 19.6%, TEM: 3.29 %BF) was lower than BB. Our modification of the BB method resulted in similar measurement consistency with the originating method. The BB method appears to represent a valid surrogate measure of %BF, superior to that observed with BIA

    Exercise bouts at three different intensities fail to potentiate concentric power

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    Postactivation potentiation (PAP) has been hypothesized previously to occur during voluntary, concentric actions. We tested the hypothesis that one of at least three different intensities of conditioning exercises would evoke potentiation of power during the concentric, bench press throw (BPT). Twelve men (age = 22.9 &#; 2.7 years, bench press 1 repetition maximum (1RM) = 1.20 Ā± 0.12 kgā€¢kg-1 body weight) completed five isotonic conditioning presses at ~55, 70, and 86% 1RM, in counterbalanced order, and on separate days. Average and peak power of the BPT using a load of 55% 1RM along with surface electromyography (EMG) of the triceps brachii were collected prior to and 4-minutes following each conditioning bout. Both average and peak power and EMG values (mean Ā± SD), respectively, were evaluated using two-way analyses of variance with repeated measures. Significant main effect decreases (p \u3c 0.05) in average (-18.6 Ā± 4.9 W) and peak power (-37.4 Ā± 9.9 W) occurred across the three different intensities evaluated. No main effects or interactions were observed with the EMG data. Contrary to the previously reported hypothesis, we were unable to demonstrate that conditioning exercise, with three different intensities, can evoke potentiation of power using a load equating to that which is optimum for power production

    The Influence of Start Position, Initial Step Type, and Usage of a Focal Point on Sprinting Performance

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    International Journal of Exercise Science 6(4) : 320-327, 2013. For many athletes, sprinting acceleration is vital to sport performance. The purpose of this study was to observe the influences of starting position, type of initial step taken, and a focal point on sprinting velocity, stride length, and acceleration over a 9.1 m distance. Two trials of four conditions were video recorded in which subjects had no focal point (n = 10) or a lateral focal point (n = 9). The four conditions were: forwards (control), backwards, 90Ā° left (90Ā°L), and 90Ā° right (90Ā°R). Lower velocities (p \u3e 0.05) were observed with focal point usage from the 90Ā°R and 90Ā°L starting positions. Four initial steps were observed during the forwards, 90Ā°L, and 90Ā°R conditions: backwards step, anterior tilt with forward step, pivot-crossover step, and lateral side step. The use of a backwards step resulted in an increased velocity (+0.80 mĀ·s-1, p \u3c 0.01) for the 90Ā° turn trials and increased acceleration (+ 0.37 mĀ·s-2,p \u3c 0.01). Our results indicate that looking at a target can cause a decline in sprint velocity and acceleration over a short distance. Moreover, utilizing a backwards step to initiate a 90Ā° turn may generate more power and force, increasing their velocity for short sprints. We recommend training athletes with a target or focal points to help combat the reduced speed and initiate movement with initial backwards step

    Validity of Critical Velocity Concept for Weighted Sprinting Performance

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    International Journal of Exercise Science 11(4): 900-909, 2018. We investigated the validity of a recently developed equation for predicting sprinting times of various tactical loads based upon the performance of a running 3-min all-out exercise test (3MT). Thirteen recreationally trained participants completed the running 3MT to determine critical velocity (CV) and finite running capacity for running velocities exceeding CV (Dā€™). Two subsequent counterbalanced loaded sprints of 800 and 1000 m distances with 20 and 15% of their body mass, respectively, were evaluated. Estimated times (t, sec) for running 800 and 1000 m with a tactical load was derived using t = (D ā€“ Dā€™)/CV. Critical velocity adjusted for an added load using the following regression equation: original CV + (-0.0638 x %load) + 0.6982, D was 800 or 1000 m, and whole percentage load was ~15 or 20% of the participant\u27s body mass. From the 3MT, CV (3.80 Ā±0.5 m.s-1) and Dā€™(200 Ā±49.88 m) values were determined.The typical error of predicting actual times for the 800 and 1000 m loaded sprints were 5.6 and 10.1 s, with corresponding ICCs of 0.95 and 0.87, and coefficient of variations of 2.9 and 4.3%. The effect size differences between estimated and actual sprint times were small (0.27) and moderate (0.60) for 800 and 1000 m, respectively. The adjustment to CV through the regression equation yields small to moderate overestimates of maximally loaded sprint times for distances of 800 and 1000 m. Whether such errors remain pervasive for prescribing high-intensity interval training is unclear and requires further investigation

    Sensitivity of Prescribing High-Intensity, Interval Training Using the Critical Power Concept

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    International Journal of Exercise Science 8(3): 202-212, 2015. The critical power (CP) concept enables the calculation of time to exhaustion (tLIM) for a given power output above CP using the equation of tLIM = Wā€™/(power ā€“ CP), where Wā€™ is the curvature constant, and CP is the asymptote for the power-tLIM relationship. The CP concept offers great promise for prescribing high-intensity interval training (HIIT); however, knowledge on the conceptā€™s sensitivity is lacking (i.e., how much of a difference in Wā€™ expenditure is needed to evoke different metabolic responses). We tested if two different power-tLIM configurations expending identical proportions of Wā€™ would evoke different end-exercise oxygen uptake (VO2) and heart rate (HR) values. Five men and five women completed a graded exercise test, 3-min all-out exercise tests, and intervals prescribed to deplete either 70 or 80% of Wā€™ on separate visits. Consistency statistics of intraclass correlation (ICC a), standard error of measure (SEM), and coefficient of variation (CV) were calculated on end-exercise values. End-exercise VO2 were similar for the 3.5- and 5-min bouts, depleting 70% of Wā€™ (ICC a = 0.91, SEM = 3.23 mLĀ·kg-1Ā·min-1, CV = 8.1%) and similar for the 4- and 5-min bouts, depleting 80% of Wā€™ (ICC a = 0.95, SEM = 2.34 mLĀ·kg-1Ā·min-1, CV = 8.1%). No VO2 differences were observed between trials or conditions (p = 0.58). Similarly, HR values (~181 bĀ·min-1) did not differ between trials or conditions (p = 0.45). Use of the CP concept for HIIT prescriptions of different power-tLIM configurations evokes similar end-exercise VO2 values on a given day. Our findings indicate that \u3e10% Wā€™ depletion is necessary to evoke different metabolic responses to HIIT

    Monitoring interval-training responses for swimming using the 3-min all-out exercise test.

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    International Journal of Exercise Science 9(5): 545-553, 2016. The purpose of this study was to determine whether the 3-min all-out exercise test (3MT) could be applied to create an off-season high intensity, interval training (HIIT) program to improve performance, specifically critical velocity (CV), in the sport of swimming. We tested a group of competitive female swimmers (age = 19 Ā± 1 yrs, height = 169 Ā± 7 cm, body mass = 69 Ā± 9 kg) to determine their swimming CV and finite energy capacity \u3eCV (Dā€™), and created a four week (2 dāˆ™wk-1) personalized interval training program. Participants were divided in to two groups, a 150yd interval group (n =11) and a 250yd interval group (n =6). Each group completed a series of intervals designed to deplete a given percentage of Dā€™ at velocities exceeding CV. A 3MT following the training period was administered to assess for any changes in CV, Dā€™, average velocity during the first 150s of the test (V150s) and total distance traveled (D). Both groups improved their CV (+0.04 māˆ™s-1), V150s (+0.03 māˆ™s-1) and D (+8.64 m) (p \u3c 0.05), however, significant interactions for Dā€™ between groups was not observed (p \u3e 0.05). We conclude that HIIT prescriptions based on a 3MT can improve swim performance over a four-week period. Future research on the fidelity of measuring CV and Dā€™ using a swimming 3MT is needed to help aid practitioners in interpreting true training adaptations

    Predicting Maximal Oxygen Uptake Using the 3-Minute All-Out Test in High-Intensity Functional Training Athletes

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    Maximal oxygen uptake (VO2max) and critical speed (CS) are key fatigue-related measurements that demonstrate a relationship to one another and are indicative of athletic endurance performance. This is especially true for those that participate in competitive fitness events. However, the accessibility to a metabolic analyzer to accurately measure VO2max is expensive and time intensive, whereas CS may be measured in the field using a 3 minute all-out test (3MT). PURPOSE: Therefore, the purpose of this study was to examine the relationship between VO2max and CS in high-intensity functional training (HIFT) athletes. METHODS: Twenty-five male and female (age: 27.6 Ā± 4.5 years; height: 174.5 Ā± 18.3 cm; weight: 77.4 Ā± 14.8 kg; body fat: 15.7 Ā± 6.5%) HIFT athletes performed a 3MT as well as a graded exercise test with 48 h between measurements. True VO2max was determined using a square-wave supramaximal verification phase and CS was measured as the average speed of the last 30 s of the 3MT. RESULTS: A statistically significant and positive correlation was observed between relative VO2max and CS values (r = 0.819, p \u3c 0.001). Based on the significant correlation, a linear regression analysis was completed, including sex, in order to develop a VO2max prediction equation (VO2max (mL/kg/min) = 8.449(CS) + 4.387(F = 0, M = 1) + 14.683; standard error of the estimate = 3.34 mL/kg/min). Observed (47.71 Ā± 6.54 mL/kg/min) and predicted (47.71 Ā± 5.7 mL/kg/min) VO2max values were compared using a dependent t-test and no significant difference was displayed between the observed and predicted values (p = 1.000). The typical error, coefficient of variation, and intraclass correlation coefficient were 2.26 mL/kg/min, 4.90%, and 0.864, respectively. CONCLUSION: The positive and significant relationship between VO2max and CS suggests that the 3MT may be a practical alternative to predicting maximal oxygen uptake when time and access to a metabolic analyzer is limited

    Spatting restricts ankle motion more effectively than taping during exercise

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    Ankle injuries, via plantarflexion (PF) and inversion, are commonplace today. To reduce ankle injuries, restrictive appliances such as taping and bracing have been employed. These appliances, however, have the disadvantage of potentially loosening considerably with mild activity. Spattingā€”applying tape over the shoe and sockā€”has been suggested as a viable alternative, yet its efficacy has not been researched widely. We examined the effects of taping or spatting the ankles on 17 men (age = 20.7 Ā± 2.1 years; height = 185.7 Ā± 5.7 cm; mass = 93.6 Ā± 16.2 kg) before, during, and after 60 minutes of exercise involving multi-directional activity. Active range of motion (ROM) for PF and inversion was measured via goniometry for each subject\u27s dominant leg to establish baseline values. ROM was measured after the appliances were applied, then following a five-minute warm-up period, and after each of three, 20-minute exercise periods. The subjects also completed a 5-item, 5-point Likert-type scale survey regarding their perceptions of each ankle appliance with respect to comfort, effectiveness, and protective ability. Separate, two-way ANOVAs with repeated measures were used to assess differences in PF and inversion ROM relative to time. A series of Wilcoxon tests were used to assess the Likert-type scale survey. In comparison to spatting, taping loosened by ~5Ā° for PF at 40 minutes and by ~3Ā° for inversion at 20 minutes (both significant interactions, p \u3c 0.01). Thus indicating that spatting is more restrictive than taping after 20 minutes of exercise. Interestingly, taping was perceived as more comfortable than spatting (Z = 2.03, p = 0.04); nonetheless, the perceived protection along with the perceived ability to move before, during, and after exercise was rated similarly between the appliances (p \u3e 0.05). Despite an advantage of restricting PF and inversion during exercise with spatting, it is not known if the loss of tape-skin contact underscores the potential benefits associated with the neuromuscular reactivity that have been reported with taping. Additional research is needed to clarify this issue
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