Danielle E. Levitt

Effect of Acute Alcohol Ingestion on Resistance Exercise-Induced mTORC1 Signaling in Human Muscle.

Abstract Duplanty, AA, Budnar, RG, Luk, HY, Levitt, DE, Hill, DW, McFarlin, BK, Huggett, DB, and Vingren, JL. Effect of acute alcohol ingestion on resistance exercise–induced mTORC1 signaling in human muscle. J Strength Cond Res 31(1): 54–61, 2017—The purpose of this project was to further elucidate the effects postexercise alcohol ingestion. This project had many novel aspects including using a resistance exercise (RE) only exercise design and the inclusion of women. Ten resistance-trained males and 9 resistance-trained females completed 2 identical acute heavy RE trials (6 sets of Smith machine squats) followed by ingestion of either alcohol or placebo. All participants completed both conditions. Before exercise (PRE) and 3 (+3 hours) and 5 (+5 hours) hours postexercise, muscle tissue samples were obtained from the vastus lateralis by biopsies. Muscle samples were analyzed for phosphorylated mTOR, S6K1, and 4E-BP1. For men, there was a significant interaction effect for mTOR and S6K1 phosphorylation. At +3 hours, mTOR and S6K1 phosphorylation was higher for placebo than for alcohol. For women, there was a significant main effect for time. mTOR phosphorylation was higher at +3 hours than at PRE and at +5 hours. There were no significant effects found for 4E-BP1 phosphorylation in men or women. The major findings of this study was that although RE elicited similar mTORC1 signaling both in men and in women, alcohol ingestion seemed to only attenuate RE-induced phosphorylation of the mTORC1 signaling pathway in men. This study provides evidence that alcohol should not be ingested after RE as this ingestion could potentially hamper the desired muscular adaptations to RE by reducing anabolic signaling, at least in men.

The acute testosterone, growth hormone, cortisol and interleukin-6 response to 164-km road cycling in a hot environment.

Abstract This study investigated the acute endocrine responses to a 164-km road cycling event in a hot environment. Thirty-four male experienced cyclists (49.1 ± 8.3 years, 86.8 ± 12.5 kg, 178.1 ± 5.1 cm) participating in a 164-km road cycling event were recruited. Blood samples were collected within 0.3–2.0 h before the start (PRE: ~0500–0700 h) and immediately following the ride (POST). Samples were analysed for testosterone, growth hormone (GH), cortisol and interleukin-6 (IL-6). The temperature and humidity during the event were 35.3 ± 4.9°C and 47.2 ± 14.0%, respectively. Based on the finishing time, results for the fastest (FAST, 305 ± 10 min) and the slowest (SLOW, 467 ± 31 min) quartiles were compared. At POST, testosterone concentration was significantly (P < 0.05) lower (PRE, 20.8 ± 8.6; POST, 18.2 ± 6.7 nmol · L−1), while GH (PRE, 0.3 ± 0.1; POST, 2.3 ± 0.3 µg · L−1), cortisol (PRE, 661 ± 165; POST, 1073 ± 260 nmol · L−1) and IL-6 (PRE, 4.0 ± 3.4; POST, 22.4 ± 15.2 pg · mL−1) concentrations were significantly higher than those at PRE. At POST, GH and cortisol were significantly higher for the FAST group than for the SLOW group (GH, 3.6 ± 2.0 and 1.0 ± 0.8 µg · L−1; cortisol, 1187 ± 209 and 867 ± 215 nmol · L−1). Participation in an ultra-endurance road cycling event in a hot environment induced significant acute changes in concentrations of circulating hormones, with a greater augmentation of GH and cortisol in those completing the ride fastest.

Blood Hemostatic Changes During an Ultraendurance Road Cycling Event in a Hot Environment

OBJECTIVE This study aims to examine blood hemostatic responses to completing a 164-km road cycling event in a hot environment. METHODS Thirty-seven subjects (28 men and 9 women; 51.8±9.5 [mean±SD] y) completed the ride in 6.6±1.1 hours. Anthropometrics (height, body mass [taken also during morning of the ride], percent body fat [%]) were collected the day before the ride. Blood samples were collected on the morning of the ride (PRE) and immediately after (IP) the subject completed the ride. Concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers (platelet factor 4, β-thromboglobulin, von Willebrand factor antigen, thrombin-antithrombin complex, thrombomodulin, and D-Dimer) were measured. Associations between changes from PRE- to IP-ride were examined as a function of event completion time and subject characteristics (demographics and anthropometrics). RESULTS All blood hemostatic markers increased significantly (P < .001) from PRE to IP. After controlling for PRE values, finishing time was negatively correlated with platelet factor 4 (r = 0.40; P = .017), while percent body fat (%BF) was negatively correlated with thrombin-antithrombin complex (r = -0.35; P = .038) and to thrombomodulin (r = -0.36; P = .036). In addition, male subjects had greater concentrations of thrombin-antithrombin complex (d = 0.63; P < .05) and natural logarithm thrombomodulin (d = 6.42; P < .05) than female subjects. CONCLUSION Completing the 164-km road cycling event in hot conditions resulted in increased concentrations of platelet, platelet activation, coagulation, and fibrinolytic markers in both men and women. Although platelet activation and coagulation occurred, the fibrinolytic system markers also increased, which appears to balance blood hemostasis and may prevent clot formation during exercise in a hot environment.

Measurement of T‐Cell Telomere Length Using Amplified‐Signal FISH Staining and Flow Cytometry

Exposure to pathogen‐associated molecular patterns (PAMPS), damage‐associated molecular patterns (DAMPS), and physiologically challenging stimuli either positively or negatively affect leukocyte maturity. Cellular maturity has implications for the effectiveness of host response to bacterial or viral infection and/or tissue injury. Thus, the ability to accurately assess cellular maturity and health is important to fully understand immune status and function. The most common technique for measuring cellular maturity is to measure telomere length; however, existing techniques are not optimized for single‐cell measurements using flow cytometry. Specifically, existing methods used to measure telomere length are PCR‐based, making it difficult for a researcher to measure maturity within specific leukocyte subsets (e.g., T cells). In this report, we describe a new approach for the measurement of telomere length within individual T cells using an amplified fluorescence in situ hybridization (FISH) technique (PrimeFlow RNA Assay). The unique aspect of this technique is that it amplifies the fluorescent signal rather than the target up to 3000‐fold, resulting in the detection of as few as 1 copy of the target nucleic acid. While the current technique focuses on human T cells, this method can be broadly applied to a variety of cell types and disease models.

Acute Effect of Whole-Body Vibration Warm-up on Footspeed Quickness.

Abstract Donahue, RB, Vingren, JL, Duplanty, AA, Levitt, DE, Luk, H-Y, and Kraemer, WJ. Acute effect of whole-body vibration warm-up on footspeed quickness. J Strength Cond Res 30(8): 2286–2291, 2016—The warm-up routine preceding a training or athletic event can affect the performance during that event. Whole-body vibration (WBV) can increase muscle performance, and thus the inclusion of WBV to the warm-up routine might provide additional performance improvements. The purpose of this investigation was to examine the acute effect of a WBV warm-up, using a vertical oscillating platform and a more traditional warm-up protocol on feet quickness in physically active men. Twenty healthy and physically active men (18–25 years, 22 ± 3 years, 176.8 ± 6.4 cm, 84.4 ± 11.5 kg, 10.8 ± 1.4% body fat) volunteered for this study. A 2 × 2 factorial design was used to examine the effect of 4 warm-up scenarios (no warm-up, traditional warm-up only, WBV warm-up only, and combined traditional and WBV warm-up) on subsequent 3-second Quick feet count test (QFT) performance. The traditional warm-up consisted of static and dynamic exercises and stretches. The WBV warm-up consisted of 60 seconds of vertical sinusoidal vibration at a frequency of 35 Hz and amplitude of 4 mm on a vibration platform. The WBV protocol significantly (p ⩽ 0.0005, &eegr;2 = 0.581) augmented QFT performance (WBV: 37.1 ± 3.4 touches; no-WBV: 35.7 ± 3.4 touches). The results demonstrate that WBV can enhance the performance score on the QFT. The findings of this study suggest that WBV warm-up should be included in warm-up routines preceding training and athletic events which include very fast foot movements.