EFFECT OF BLOOD FLOW RESTRICTION TRAINING AT VARIABLE LOADS AND REPETITION SPEEDS ON MUSCULAR FATIGUE

John C. Sieverdes, Korey C. Little, Wesley D. Dudgeon. College of Charleston, Charleston, SC. BACKGROUND: Blood flow restriction (BFR) is a training method used to restrict venous return by partially occluding limbs to increase metabolic stress using lighter loads during exercise training. This modality has been proven to increase muscular conditioning and elicit changes in muscular cross-sectional area and endurance. Conventional BFR training methodologies often utilize a 30-15-15-15 rep scheme. The purpose of this study is to investigate the feasibility of other exercise parameters on time-under tension (TUT) and load interactions on muscular fatigue. METHODS: Five resistance-trained men (mean age = 21.0 [SD1.9] yrs) attended 3 laboratory visits. Baseline biceps brachii peak torque was assessed using an isokinetic arm curl protocol on a Biodex dynamometer. Four BFR arm-curl conditions (i.e., all 30% occlusion with 30 second rest between sets) were randomized to each arm for per visit resulting in 5 measures for each condition (A: standard 30% 1RM, 30,15,15,15 reps 3 sec/rep; B: 50% 1RM, 15, 10, 10, 10 reps, 6 sec/rep; C: 30%1RM, 12, 9, 9, 9 reps, 6 sec/rep; D:50%1RM, 15, 10, 10, 10, 10, 3 sec/rep. Blood lactate was assessed for 5 minutes after the exercise with peak arm isokinetic curl torque measured at 7 minutes. RESULTS: Participants were able to complete 91% of condition A’s repetitions, 41% of condition B, 99% of condition C, and 68% of condition D. RPE was highest for condition B, followed by D, A, then C. Muscular time by load burden was calculated by TUT and TUT x load. Condition A had notably higher session TUT (191 sec; p = .035) and TUT x load = 7388.11 sec*kg (p = .001) compared to the next highest condition C (TUT = 109, TUT * load = 1994.9 sec*kg. Non-statistically significant changes in max isokinetic torque between baseline and conditions showed fatigue for A (-3.9 [SD8.62]) but not for B (1.27 [SD 11.04]), C (3.47 [SD 10.17]), or D (2.17 [SD 9.4]). Peak lactate trended higher for condition A at 3.8 (SD.86) and B at 3.5 (SD.61) with conditions D (3.0 [SD1.02]) and C (2.4 [SD.68]) being lower (p-value = .074). CONCLUSION: Increasing the %1RM and or slowing rep speed resulted in participants not meeting the repetition targets and resulted in significantly lower exercise volume than the standard 30%1RM with a 30, 15, 15, 15 repetition scheme

ROLE OF SHORT DURATION INTERMITTENT FASTING ON ACUITY AND BODY COMPOSITION IN YOUNG ADULT FEMALES

Lauren P. Durkee, John C. Sieverdes, Wesley D. Dudgeon. College of Charleston, Charleston, SC. BACKGROUND: Intermittent fasting (IF) is a dietary method to restrict caloric intake during a limited time of day. Clinical trials have found mixed results in changes of body composition and improved cognitive affective states such as concentration and mental acuity. Evidence to date has predominantly focused on middle-aged adults with pre-existing conditions. Therefore, the primary purpose of this feasibility study was to explore the effects of short-term (4-weeks) IF on mental acuity in young women, with secondary interest changes in body composition. METHODS: Twenty-two female subjects were randomized to either IF (n = 11) or a control groups (n = 11). The IF group was instructed to only consume calories in an 8-hour window each day for 4 weeks without intentionally changing the type/amounts of food they consumed. Baseline, mid-point and follow-up physical measures included Dual-X-ray absorptiometry (DEXA) to assess body composition while acuity testing included Cogstate computer-based testing with additional measures of alertness (i.e., Zogim-A and fatigue (FSS)). RESULTS: No statistically significant differences between groups were found for Cogstate testing measurements including psychomotor function, information processing speed, visual attention, visual learning, working memory and attention or for FSS or Zogim-A scales. IF group analysis showed improvements in visual learning (i.e. One Card Learning test) at 2 weeks (delta = .077 [SD.11], p = .05) and at 4 weeks (delta = .078 [SD .06], p = .002) with effect sizes of .674 and 1.30, respectively. Additionally, both groups increased their paired associate learning scores at 2 weeks (IF: p = .02, Cohen’s d = .832; control: p = .10 Cohen’s d = .884) and 4 weeks (IF: p = .001, Cohen’s d = 1.346, control: p = .023, Cohen’s d = .808). There were no observed changes in weight status, body fat, or lean mass over the course of the 4-week intervention. CONCLUSIONS: This pilot feasibility study found small changes in the visual learning domain of acuity during the 4-week trial IF trial. Implications of the trial suggest that other cognitive or acuity measures may be more sensitive to IF as the present study reported minimal findings. Future studies could focus on longer intervention durations, other cognitive measures or investigate diet restriction in conjunction with IF

DYNAMIC BALANCE AND CORE ENDURANCE IMPROVE IN HEALTHY FEMALES FOLLOWING SUSPENSION TRAINING

Emily Cavallaro, Kate Pfile, J. Megan Irwin, Wesley D. Dudgeon. College of Charleston, Charleston, SC. BACKGROUND: Many exercise modalities have been developed and marketed to improve core muscle function, and likewise there are multiple training programs that aim to improve balance. These variables are of interest given they are inherent to performing activities of daily living (ADLs) and maintaining physical activity levels. Our previous work has shown that TRX suspension training (SuT) is effective at improving body composition, muscular strength and muscular endurance in college aged females; however, the very nature of this exercise modality should also improve core muscle function and balance. The purpose of this study is to determine the effectiveness of six weeks of SuT in improving balance and core muscle function. METHODS: Sixteen SuT naïve females (19.6 +/-1.5 yrs; 167.3+/-4.6 cm; 62.4+/-7.4 kg) progressed through a six-week supervised training program consisting of 18 50-60-minute interval style workouts. Control subjects (n=5) maintained their normal activity levels. Dynamic balance was assessed using the Star Excursion Balance Test (SEBT). Static balance was assessed using the Balance Error Scoring System (BESS). Core endurance was assessed using the Endurance Plank Test. The same test protocols were used for pre and post testing. RESULTS: Dependent measures t-test analysis showed improvements (p\u3c.05) in right leg stance SEBT scores (expressed as percentage of reference leg length) in all directions: anterior (pre=75.3+/-4.8, post=81.9+/10c %), posteromedial (105+/-13.3 to 116+/-14.1 %) and posterolateral (97.0+/-10.7 to 105.1+/-10.4 %). The SuT group also showed left leg improvements (p\u3c.05) in the anterior (74.8+/-4.4 to 81.0+/- 11.8 %), posteromedial (105.6+/-711.9 to 113.0 +/- 12.3 %) and posterolateral (98.3+/-12.4 to 108.0+/-11.1 %) directions. There was an improvement in plank time (105.2+/-40.6 to 141.6+/-46.9 seconds: p\u3c.05) in the SuT group. No difference in BESS scores were observed over time. There were no changes in any dependent variables in the control group. CONCLUSIONS: These data suggest that six weeks of SuT facilitated improvements in bilateral dynamic balance and core endurance. Additional work is needed to assess additional core stability and balance measures as well as to explain the lack of improvements observed in static postural control

The Ecology of Tropical Asian Rivers and Streams in Relation to Biodiversity Conservation

Tropical Asian rivers support a rich but incompletely known biota, including a host of fishes, a diverse array of benthic invertebrates, and an assemblage of mammals adapted to riverine wetlands. River ecology is dominated by flow seasonality imposed by monsoonal rains with profound consequences for fishes and zoobenthos. Information on life histories, feeding, and the trophic base of production of these animals is summarized. Widespread use of allochthonous foods by fishes and zoobenthos is apparent. Migration by fishes is often associated with breeding and results in seasonal occupation of different habitats. Riverine biodiversity is threatened by habitat degradation (pollution, deforestation of drainage basins), dams and flow regulation, as well as over-harvesting. Conservation efforts in tropical Asia are constrained by a variety of factors, including lack of ecological information, but the extent of public awareness and political commitment to environmental protection are likely determinants of the future of riverine biodiversity.link_to_subscribed_fulltex