IV NSCA International Conference respect to parallel squat after the firsts 10 minutes of recovery. Discussion: Since normotensive population have a reduced PEH and the low total volume used in this study, PEH was not observed. FS, the more demanding protocol, had a lower session SBP in comparison with CS, suggesting that recovery BP could be affected by set configurations with more metabolic stimulation. Also, the differences between exercises in DBP after the first 10 minutes of recovery could indicate that recovery BP can be affect by the exercise performed, as reported previously. results of this study indicate that individual evaluation of the rCHOmp in male marathon runners may help them to design the strategy of exogenous CHO intake and prevent early depletion of CHO availability and performance deterioration. Mail to: elzach@phed.uoa.gr. EFFECT OF A BOUT OF STRENGTH EXERCISE UNTIL FAILURE ON HEART RATE VARIABILITY HUERTAS, F,1 BERMEJO, JL,1 BALLESTER, R,1 PALMA, V,1 MAESTRE, C,1 AND PABLOS, C1 RATE OF CARBOHYDRATE USE VARIABILITY AT MARATHON PACE IN ENDURANCE RUNNERS de Gestio´n y Ciencias Aplicadas a la Actividad Fı´sica, Universidad Cato´lica de Valencia, Valencia, Spain ZACHAROGIANNIS, E, PARADISIS, G, PAGOTO, F, TZIORTZIS, S, ARGITAKI, P, AND SMIRNIOTOU, A Introduction: Heart rate variability (HRV) is one of the most promising non-invasive measures to provide additional valuable insight into physiological conditions associated to the functioning of the autonomic nervous system (ANS). There are many studies about the relationship between aerobic exercise and HRV response. However, there are few references which have considered the effect of bout of strength exercises on HRV. This study aims to analyze HRV at rest and while performing strength exercises, to establish the relationship between changes in HRV and physical work in a short period of time. Method and Design: 17 soldiers of the Spanish Army (age = 33.7 6 4.5), underwent assessment of HRV at rest and during a strength exercise. The HRV signal was analyzed in time and frequency domains. Participants came to the laboratory in 2 sessions: Session 1: Testing session to determine the load 1-repetition maximum (1RM) and linked to maximal power (Pmax), and Session 2 (after 48–72 hours rest): Strength Exercise Session: 6 sets of repetitions until failure with 3 power loads: (a) Loading 15% lower than Pmax, (b) Burden related to Pmax and (c) Loading 15% higher than Pmax. Results: During rest condition, soldiers presented higher values when compared to values in exercise for the variables SDNN [53.23 (19.54) vs. 48.57 (18.18)], RMSD [57.55 (28.36) vs. 37.45 (21.36)] and pNN50 (28.94 (21.05) vs. 13.05 (12.15)], as well as lower values of LFnu [(54.74 (18.12) vs. 79 82 (8.95)], HFnu [45.26 (18.12) vs. 20.18 (8.95)] and LF/HF [1.70 (1.42 ) vs. 4.92 ( 2.41 )], but these differences did not reach the statistical significance. More importantly, we found a significant increase from rest to exercise condition in LF / HF (p , 0.001) and a decreased value of RMSSD (p = 0.002) and pNN50 (p = 0.002) Discussion: In line with other studies we found a significant increase in LF/HF during the performance of high intensity exercise compared with rest, which is an indicator of activation of the sympathetic nervous system (SNS). By Department of Track & Field, Faculty of Physical Education and Sports Science, University of Athens, Greece Introduction: Carbohydrate (CHO) is a critical fuel for prolonged muscle contraction, however the body’s ability to store CHO, primarily in the form of liver and muscle glycogen is relatively limited and with the exhaustion of carbohydrate reserves performance decrements are inevitable. The amount of glycogen stored in muscle and liver whether a recreational athlete or an elite competitor limited to 400–600 g. The rate of CHO utilization (rCHO) ranges from 1 - 5.8 g$min21 in prolonged submaximal running (60–80% V_ O2max) and can be decisive for the duration of submaximal effort before depletion of the limited CHO reserves. There are, however, no systematically collected descriptive data regarding the rCHO metabolism during low intensity prolonged marathon pace (MP). The aim of this study was to investigate the rate of CHO usage at mean marathon pace (rCHOmp). Methods: Trained (n = 167) male runners (age 41 6 7.9, weight 79.4 6 8.14, and V_ O2max 59.62 6 6.72) performed, 7–21 days before a marathon race, an incremental test (0% inclination, 3 minutes stages until RER 1.0 then 2 minutes stages to volitional fatigue) to determine V_ O2max and ventilatory threshold (VT). Fat, CHO oxidation and energy expenditure were calculated using stoichiometric equations. Mean marathon pace (km$h21) was also used for analysis. Results: Mean 6 SD rCHOmp, %V_ O2max at MP and MP were 3.1 6 0.81 g$min21, 78.04 6 2.38 and 11.75 6 1.89 km$h21 respectively. The marathon performance range was 2 h: 16 minutes :35 s—5 h: 15 minutes: 48 s. The rCHOmp ranged from 1.5–5.8 g$min–1 with a coefficient of variation (CV) 26.03%. Low correlations (p . 0.05) were found between rCHOmp with MP and V_ O2max. Discussion: The 52 the 1Departamento TM Journal of Strength and Conditioning Research Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited. the TM Journal of Strength and Conditioning Research contrast, RMSSD and pNN50 temporary components reduced under strength exercise conditions. This data pattern indicates a reduced parasympathetic activity. HRV can be a useful indicator to coaches and athletes for monitoring short term training effect. Mail to: jl.bermejo@ucv.es. RATE OF CARBOHYDRATE USAGE VARIABILITY AT MARATHON PACE IN ENDURANCE FEMALE RUNNERS PARADISIS, GP,1 ZACHAROGIANNIS, E,1 HAVENETIDIS, K,2 ARGITAKI, P,1 AND SMIRNIOTOU, A1 1Athletics Lab, Department of Track & Field, Faculty of Physical Education and Sports Science, National and Kapodistrian University of Athens, Greece; and 2Hellenic Army Academy, Greece Introduction: As carbohydrate is a critical fuel for prolonged muscle contraction, the ability of the body to store carbohydrate is essential for the final outcome, whereas the exhaustion of these reserves leads to performance deterioration. The amount of glycogen stored in muscle and liver is limited to 400–600 g (depending on level of the performer), where the rate of carbohydrate utilization ranges from 1 to 5.8 g$min21 in prolonged submaximal exercise (60–80%V_ O2max). However, there is no systematically collected descriptive data regarding the rate of carbohydrate utilization during low intensity prolonged marathon pace. The aim of this study was to investigate the rate of CHO usage at mean marathon pace for female athletes. Methods: One hundred and one trained female runners (age = 37.78 6 7.73 years, mass = 57.40 6 7.01 kg, height = 165.12 6 5.18 cm, % body fat = 20.17 6 4.60 %, and V_ O2max 50.27 6 7.24 ml$kg$r21$min21) performed, 7–21 days before the marathon race, an incremental test (3 minutes stages until RER 1.0 then 2 minutes stages to volitional fatigue, _ O2max and the ventilatory thresh0% inclination) to determine V old. Fat and CHO oxidation and energy expenditure were calculated using stoichiometric equations (1). Mean marathon pace (km$h21) was also used for analysis. Results: The mean 6 SD marathon time was 3:58:26 6 00:43:53, ranged from 02:48:47 to 07:01:57 with coefficient of variation (CV) = 18.4%, the mean marathon pace was 10.93 6 1.80 km$h21, ranged from 6.0 to 15.0 km$h21and CV = 16.4%, and the carbohydrate utilization was 2.07 6 0.57 g$min21, ranged from 1.01 to 3.90 and CV = 27.4%. Correlation coefficient between carbohydrate utilization _ O2max were and marathon time, mean marathon pace and V -0.40, 0.47 and 0.38 respectively. When the group divided according to the marathon time, the carbohydrate utilization for | www.nsca.com good (marathon time ,03:30:00), medium (04:40:00 . marathon time .03:30:00) and novice (marathon time . 04:40:00) runners were 2.36 6 0.58, 2.08 6 0.55 and 1.72 6 0.41g$min21. Conclusions: The results of this study showed that individual evaluation of the carbohydrate utilization in female marathon runners is required in order to design the strategy of exogenous carbohydrate intake and to ovoidthe early fuel depletion for better performance. NUTRITION STATUS OF THAI NATIONAL TEAM WEIGHTLIFTERS TUMNARK, P,1,2 PHUCHAIWATTANANON, O,3 KERDCHANTUK, S,4 CONCEIÇÃO, F,1 AND VILAS BOAS, JP1 1CIFI2D, Faculty of Sport, and LABIOMEP, University of Porto, Porto, Portugal; 2Faculty of Sports Science, Kasetsart University, Kamphaeng Saen Campus, Thailand; 3Faculty of Medicine, Ramathibodi Hospital, Bangkok, Thailand; and 4Sports Authority of Thailand, Bangkok, Thailand Introduction: Weightlifting is one of the most powerful athletic activities in the world of sport. In Thailand, weightlifting is the most successful Olympic sport along with boxing. It is one of the only 2 sports in which Thailand has won gold, with 3 weightlifting gold medals won in the last 3 Olympic Games. Weightlifting demands extreme strength and power to lift very heavy weights in a controlled manner. The aim of these athletes is to build muscle bulk and target the main muscles that are used for the bar movement. A high level of muscularity is therefore required by both male and female competitors. Maintaining low body fat is also a physical requirement often demanded to optimize the power to weight ratio of lifters, helping to achieve best performance. Besides providing the energy for training and for its recovery, nutrition also promotes training adaptations, including skeletal muscle hypertrophy. The aim of this study was to diagnose the nutritional status of Thai Weightlifters. Methods: The sample was composed of 37 weightlifters, aged 15–24 yr, 18 males (17.9 6 2.8 yr) and 19 females (18.7 6 2.6 yr). They completed anthropometric assessment, 3-day food record analyzed for macro- and micronutrient intake. In order to report the result as accurately as possible, the researchers took a photo of all the food that subjects had been eaten and weighed the items using a weighing scale. Energy expenditure was estimated using predictive equations (factorial method). Results: Mean percent fat was 11.6 6 3.4 and 20.6 6 6.0%, body mass index was 25.7 6 2.8 and 25.8 6 5.6 kg/m2 for men and women, respectively. Mean energy intake was 2,655 6 270.6 and 2,150 6 282.8 VOLUME 28 | NUMBER 11 | NOVEMBER 2014 | 53 Copyright © National Strength and Conditioning Association Unauthorized reproduction of this article is prohibited.