Courtenay Dunn-Lewis

EFFECTS OF A WHOLE BODY COMPRESSION GARMENT ON MARKERS OF RECOVERY AFTER A HEAVY RESISTANCE WORKOUT IN MEN AND WOMEN

Kraemer, WJ, Flanagan, SD, Comstock, BA, Fragala, MS, Earp, JE, Dunn-Lewis, C, Ho, J-Y, Thomas, GA, Solomon-Hill, G, Penwell, ZR, Powell, MD, Wolf, MR, Volek, JS, Denegar, CR, and Maresh, CM. Effects of a whole body compression garment on markers of recovery after a heavy resistance workout in men and women. J Strength Cond Res 24(3): 804-814, 2010-The primary purpose of this investigation was to evaluate the influence of a whole body compression garment on recovery from a typical heavy resistance training workout in resistance-trained men and women. Eleven men (mean ± SD: age, 23.0 ± 2.9 years) and 9 women (mean ± SD: age 23.1 ± 2.2 years) who were highly resistance trained gave informed consent to participate in the study. A within-group (each subject acted as their own control), balanced, and randomized treatment design was used. Nutritional intakes, activity, and behavioral patterns (e.g., no pain medications, ice, or long showers over the 24 hours) were replicated 2 days before each test separated by 72 hours. An 8-exercise whole body heavy resistance exercise protocol using barbells (3 sets of 8-10 repetition maximum, 2.0-to 2.5-minute rest) was performed after which the subject showered and put on a specific whole body compression garment one designed for women and one for men (CG) or just wore his/her normal noncompression clothing (CON). Subjects were then tested after 24 hours. Dependent measures included sleep quality, vitality rating, resting fatigue rating, muscle soreness, muscle swelling via ultrasound, reaction movement times, bench throw power, countermovement vertical jump power, and serum concentrations of creatine kinase (CK) measured from a blood sample obtained via venipuncture of an arm vein. We observed significant (p ≤ 0.05) differences between CG and CON conditions in both men and women for vitality (CG > CON), resting fatigue ratings (CG < CON), muscle soreness (CG < CON), ultrasound measure swelling (CG < CON), bench press throw (CG > CON), and CK (CG < CON). A whole body compression garment worn during the 24-hour recovery period after an intense heavy resistance training workout enhances various psychological, physiological, and a few performance markers of recovery compared with noncompressive control garment conditions. The use of compression appears to help in the recovery process after an intense heavy resistance training workout in men and women.

Whey Protein Supplementation During Resistance Training Augments Lean Body Mass

Compared to soy, whey protein is higher in leucine, absorbed quicker and results in a more pronounced increase in muscle protein synthesis. Objective: To determine whether supplementation with whey promotes greater increases in muscle mass compared to soy or carbohydrate, we randomized non-resistance-trained men and women into groups who consumed daily isocaloric supplements containing carbohydrate (carb; n = 22), whey protein (whey; n = 19), or soy protein (soy; n = 22). Methods: All subjects completed a supervised, whole-body periodized resistance training program consisting of 96 workouts (∼9 months). Body composition was determined at baseline and after 3, 6, and 9 months. Plasma amino acid responses to resistance exercise followed by supplement ingestion were determined at baseline and 9 months. Results: Daily protein intake (including the supplement) for carb, whey, and soy was 1.1, 1.4, and 1.4 g·kg body mass−1, respectively. Lean body mass gains were significantly (p < 0.05) greater in whey (3.3 ± 1.5 kg) than carb (2.3 ± 1.7 kg) and soy (1.8 ± 1.6 kg). Fat mass decreased slightly but there were no differences between groups. Fasting concentrations of leucine were significantly elevated (20%) and postexercise plasma leucine increased more than 2-fold in whey. Fasting leucine concentrations were positively correlated with lean body mass responses. Conclusions: Despite consuming similar calories and protein during resistance training, daily supplementation with whey was more effective than soy protein or isocaloric carbohydrate control treatment conditions in promoting gains in lean body mass. These results highlight the importance of protein quality as an important determinant of lean body mass responses to resistance training.

Validity of the Myotest® in Measuring Force and Power Production in the Squat and Bench Press

Comstock, BA, Solomon-Hill, G, Flanagan, SD, Earp, JE, Luk, H-Y, Dobbins, KA, Dunn-Lewis, C, Fragala, MS, Ho, J-Y, Hatfield, DL, Vingren, JL, Denegar, CR, Volek, JS, Kupchak, BR, Maresh, CR, and Kraemer, WJ. Validity of the myotest® in measuring force and power production in the squat and bench press. J Strength Cond Res 25(8): 2293-2297, 2011—The purpose of this study was to verify the concurrent validity of a bar-mounted Myotest® instrument in measuring the force and power production in the squat and bench press exercises when compared to the gold standard of a computerized linear transducer and force platform system. Fifty-four men (bench press: 39-171 kg; squat: 75-221 kg) and 43 women (bench press: 18-80 kg; squat: 30-115 kg) (age range 18-30 years) performed a 1 repetition maximum (1RM) strength test in bench press and squat exercises. Power testing consisted of the jump squat and the bench throw at 30% of each subjects 1RM. During each measurement, both the Myotest® instrument and the Celesco linear transducer of the directly interfaced BMS system (Ballistic Measurement System [BMS] Innervations Inc, Fitness Technology force plate, Skye, South Australia, Australia) were mounted to the weight bar. A strong, positive correlation (r) between the Myotest and BMS systems and a high correlation of determination (R2) was demonstrated for bench throw force (r = 0.95, p < 0.05) (R2 = 0.92); bench throw power (r = 0.96, p < 0.05) (R2 = 0.93); squat jump force (r = 0.98, p < 0.05) (R2 = 0.97); and squat jump power (r = 0.91, p < 0.05) (R2 = 0.82). In conclusion, when fixed on the bar in the vertical axis, the Myotest is a valid field instrument for measuring force and power in commonly used exercise movements.

LOWER-BODY MUSCLE STRUCTURE AND ITS ROLE IN JUMP PERFORMANCE DURING SQUAT, COUNTERMOVEMENT, AND DEPTH DROP JUMPS

Earp, JE, Kraemer, WJ, Newton, RU, Comstock, BA, Fragala, MS, Dunn-Lewis, C, Solomon-Hill, G, Penwell, ZR, Powell, MD, Volek, JS, Denegar, CR, Häkkinen, KA, and Maresh, CM. Performance during squat, countermovement, and depth drop jumps. J Strength Cond Res 24(3): 722-729, 2010-The purpose of this study was to examine the relationship between lower-body muscle structure and vertical jump performance. Twenty-five resistance-trained men (age, 23.3 ± 3.2 years; height, 176.1 ± 7.4 cm; and weight, 86.2 ± 11.6 kg) took part in both anatomical and jump performance testing. Muscle fascicle thickness, fascicle length, and pennation angle were analyzed for the vastus lateralis (VL) and the lateral gastrocnemius (LG). Jump height and both relative and absolute power were measured for the squat jump (SJ), countermovement jump (CMJ), and depth drop jump (DDJ). Regressions were used to determine if jump performance could be predicted using the aforementioned structures. No VL measurements were significantly correlated with any of the jump measures. Lateral gastrocnemius pennation angle was a significant but weak predictor of jump height for all 3 jump types (SJ: r2 = 0.212, p = 0.021; CMJ: r2 = 0.186, p = 0.018; DDJ: r2 = 0.263, p = 0.005). When comparing jump height at increasing preloads, none of the variables of interest could significantly predict the jump height differences between CMJ and SJ. However, LG fascicle length had a weak but significant inverse relationship with DDJ-CMJ (r2 = 0.152; p = 0.031). Lateral gastrocnemius thickness was the strongest predictor of absolute power for all jump types and between jump types (SJ: r2 = 0.181, p = 0.034; CMJ: r2 = 0.201, p = 0.014; DDJ: r2 = 0.122, p = 0.049; CMJ-SJ: r2 = 0.201, p = 0.014; DDJ-CMJ: r2 = 0.146, p = 0.034). Lateral gastrocnemius pennation angle was also the best predictor of relative power for all 3 jump types and between jump types (SJ: r2 = 0.172, p = 0.038; CMJ: r2 = 0.416, p = 0.000; DDJ: r2 = 0.167, p = 0.024; CMJ-SJ: r2 = 0.391, p = 0.000; DDJ-CMJ: r2 = 0.136, p = 0.039). Results for jump performance differ from those previously found for sprinting in that greater pennation and shorter fascicles, positively predicting jumping ability at increased prestretch loads reinforcing the need for training specificity. Our findings in resistance-trained men indicate that where jumping is vital to athletic success one can benefit from developing LG muscle architecture along with addressing eccentric strength.

Changes in Cytokines of the Bone Microenvironment during Breast Cancer Metastasis.

It is commonly accepted that cancer cells interact with host cells to create a microenvironment favoring malignant colonization. The complex bone microenvironment produces an ever changing array of cytokines and growth factors. In this study, we examined levels of MCP-1, IL-6, KC, MIP-2, VEGF, MIG, and eotaxin in femurs of athymic nude mice inoculated via intracardiac injection with MDA-MB-231GFP human metastatic breast cancer cells, MDA-MB-231BRMS1GFP, a metastasis suppressed variant, or PBS. Animals were euthanized (day 3, 11, 19, 27 after injection) to examine femoral cytokine levels at various stages of cancer cell colonization. The epiphysis contained significantly more cytokines than the diaphysis except for MIG which was similar throughout the bone. Variation among femurs was evident within all groups. By day 27, MCP-1, MIG, VEGF and eotaxin levels were significantly greater in femurs of cancer cell-inoculated mice. These pro-osteoclastic and angiogenic cytokines may manipulate the bone microenvironment to enhance cancer cell colonization.

L-Carnitine Supplementation: Influence upon Physiological Function

Carnitine (L-3-hydroxytrimethylamminobutanoate) is a naturally occurring compound that can be synthesized in mammals from the essential amino acids lysine and methionine or ingested through diet. Primary sources of dietary carnitine are red meat and dairy products; however, commercially produced supplements also are available and have been shown to be safe in humans. Carnitine is stored primarily in skeletal muscle, with lower concentrations in plasma. Biologically, carnitine is essential for the transport of long-chain (carbon chain length = 10) fatty acids across the outer- and inner-mitochondrial membranes (carnitine palmitoyltransferanse I and II, respectively). Conflicting results characterized the early research focused on L-carnitine supplementations ability to enhance endurance performance, and studies showed no changes occurred in muscle carnitine levels. Nevertheless, promising findings for its use have been observed for various pathologies, including cardiovascular diseases, which show it might mitigate some negative effects and enhance physical function. Recent studies have focused upon a different paradigm for L-carnitine in regulating hypoxic stress and enhancing recovery from exercise.

The effects of a customized over-the-counter mouth guard on neuromuscular force and power production in trained men and women.

Abstract Dunn-Lewis, C, Luk, H-Y, Comstock, BA, Szivak, TK, Hooper, DR, Kupchak, BR, Watts, AM, Putney, BJ, Hydren, JR, Volek, JS, Denegar, CR, and Kraemer, WJ. The effects of a customized over-the-counter mouth guard on neuromuscular force and power production in trained men and women. J Strength Cond Res 26(4): 1085–1093, 2012—Although mouth guards were originally designed for injury prevention, even elite athletes are now using performance mouth guards to improve athletic success. Both expensive custom models and over-the-counter models are available, but the efficacy is not well known. Some athletes remain wary of the perceived potential for detriments using a mouth guard to their performance. Thus, the purpose of this study was to examine various physical performance tests when using a mouth guard including a customized over-the-counter mouth guard. Twenty-six trained men (25 ± 4 years; 1.78 ± 0.07 m; 83.3 ± 11.4 kg) and 24 trained women (23 ± 3 years; 1.65 ± 0.08 m; 62.6 ± 7.8 kg) volunteered for the investigation. The subjects completed a familiarization period and then balanced and randomized treatment conditions that included: (a) a customized Power Balance performance mouth guard (PB MG); (b) a regular over the counter boil-and-bite mouth guard (Reg MG); and (c) a no mouth guard (No MG) treatment condition. At each visit, the subjects completed a testing protocol that was sequenced in the following order: sit-and-reach flexibility, medial-lateral balance, visual reaction time, vertical jump, 10-m sprint, bench throw, and plyo press power quotient (3PQ). Heart rate and rating of perceived exertion (RPE) were recorded around the 3PQ. Significance was set at p ⩽ 0.05. Expected significant sex differences existed for all power, strength, and speed variables. Bench throw power (watts) and force (newtons) were significantly higher under PB MG than either Reg MG or No MG or in both men and women. The 3PQ power and force production were higher than that for the other 2 treatments for the PB MG for men only. There were no significant differences for treatment conditions in the heart rate or RPE after the 3PQ test. Men were better able to maintain significantly higher 3PQ power production under PB MG treatment condition compared with the other 2 treatment conditions. Rate of power development was significantly higher in men for the vertical jump when using the PB MG compared with that for other treatment conditions in men only. No differences were observed in flexibility, balance, visual reaction time, or sprint time. The PB MG performance mouth guard improves performance of upper-body loaded power exercises in both men and women and lower body power exercise in men without compromising performance on any other performance parameters.

Growth Hormone, Exercise, and Athletic Performance: A Continued Evolution of Complexity

Growth hormone (hGH) presents pleiotropic effects in many tissues encompassing a diverse range of physiological actions. Its complexity as a family of hormones with different isoforms and different somatotroph molecular functions continues to challenge the status quo of our understanding of its release, function, and signaling. Owing to the fact that the majority of the literature has viewed hGH from the perspective of the primary 22 kD monomer, further investigation is needed as to the influence and biological activity of other aggregate and splice variant isoforms that are released into circulation. Its role over the life span and with supplementation yields equivocal results with more study needed. Testing for the use of hGH has progressed, and the first positive test was recently documented. Understanding of pituitary function and physiology will remain complex until the use of a broader range of analytical techniques, including assays, becomes mainstream.

Effects of Fatigue From Resistance Training on Barbell Back Squat Biomechanics

Abstract Hooper, DR, Szivak, TK, Comstock, BA, Dunn-Lewis, C, Apicella, JM, Kelly, NA, Creighton, BC, Flanagan, SD, Looney, DP, Volek, JS, Maresh, CM, and Kraemer, WJ. Effects of fatigue from resistance training on barbell back squat biomechanics. J Strength Cond Res 28(4): 1127–1134, 2014—Exhaustive resistance training programs that have been previously referred to as extreme conditioning protocols have increased in popularity in military and civilian populations in recent years. However, because of their highly fatiguing nature, proprioception is likely altered during such programs that would significantly affect the safety and efficacy of such programs. Therefore, the purpose of this study was to assess the alterations in movement patterns that result from extreme conditioning protocols and to evaluate if these protocols can be deemed safe and effective. Twelve men (age 24 ± 4.2 years, height 173.1 ± 3.6 cm, weight 76.9 ± 7.8 kg, body fat percentage 9.0 ± 2.2%) and 13 women (age 24.5 ± 3.8 years, height 166.9 ± 8.5 cm, weight 66.1 ± 9.2 kg, body fat percentage 18.6 ± 4.0%) with at least 6 months of resistance training experience involving barbell bench press, barbell deadlift, and barbell back squat performed a highly fatiguing resistance training workout. During the barbell back squat, a 2-dimensional analysis was performed where the knee and hip angles were recorded throughout the 55 repetitions of the workout. At the early stages of the protocol, knee angle was significantly lower in men and in women demonstrating less knee flexion. Also, hip angle was significantly lower early in the program in men and in women, demonstrating a greater forward lean. The technique changes that occur in high repetition sets do not favor optimal strength development and may increase the risk of injury, clearly questioning the safety and efficacy of such resistance training programming. This is likely a display of self-preservation by individuals who are faced with high repetition programs.

Beneficial effects of habitual resistance exercise training on coagulation and fibrinolytic responses

BACKGROUND A sedentary lifestyle is a major risk factor for cardiovascular and thrombotic complications. While habitual endurance activity will reduce the risk of these adverse events, the influence of habitual resistance exercise is less clear. This study examined coagulation and fibrinolytic responses to an acute exhaustive resistance exercise test (AERET) in both resistance-trained (RT, min 2 yr, 5 men and 5 women) and untrained (UT, 5 men and 5 women) subjects. METHODS The AERET consisted of six sets of 10 repetitions of squats at 80% of 1-repetition maximum. Venous blood was collected pre-exercise, immediate post exercise (IP), and +15, +60, and +120 minutes post exercise. RESULTS Compared to UT, RT exhibited a lower capacity to form a clot as seen by activated partial Thromboplastin time (aPTT) integrated area under the curve over time (iAUC) levels, lower pre-exercise and 120 min post-exercise plasminogen activator inhibitor -1 (PAI-1) activity, and higher tissue plasminogen activator (tPA) activity immediately post-exercise. There were no significant differences between RT and UT for fibrinogen, prothrombin fragment 1+2 (PTF 1+2), and thrombin-antithrombin complexes (TAT). CONCLUSION These results suggest that habitual resistance exercise training may provide an enhanced fibrinolytic state.