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Dive into the research topics where Gwendolyn A. Thomas is active.

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Featured researches published by Gwendolyn A. Thomas.


Journal of Strength and Conditioning Research | 2010

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

William J. Kraemer; Shawn D. Flanagan; Brett A. Comstock; Maren S. Fragala; Jacob E. Earp; Courtenay Dunn-Lewis; Jen-Yu Ho; Gwendolyn A. Thomas; Glenn F. Jr Solomon-Hill; Zachary R. Penwell; Matthew D. Powell; Megan R. Wolf; Jeff S. Volek; Craig R. Denegar; Carl M. Maresh

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.


Journal of Strength and Conditioning Research | 2007

Maximal Power at Different Percentages of One Repetition Maximum: Influence of Resistance and Gender

Gwendolyn A. Thomas; William J. Kraemer; Barry A. Spiering; Jeff S. Volek; Jeffrey M. Anderson; Carl M. Maresh

National Collegiate Athletic Association Division I athletes were tested to determine the load at which maximal mechanical output is achieved. Athletes performed power testing at 30, 40, 50, 60, and 70% of individual 1 repetition maximum (1RM) in the squat jump, bench press, and hang pull exercises. Additionally, hang pull power testing was performed using free-form (i.e., barbell) and fixed-form (i.e., Smith machine) techniques. There were differences between genders in optimal power output during the squat jump (30–40% of 1RM for men; 30–50% of 1RM for women) and bench throw (30% of 1RM for men; 30–50% of 1RM for women) exercises. There were no gender or form interactions during the hang pull exercise; maximal power output during the hang pull occurred at 30–60% of 1RM. In conclusion, these results indicate that (a) gender differences exist in the load at which maximal power output occurs during the squat jump and bench throw; and (b) although no gender or form interactions occurred during the hang pull exercise, greater power could be generated during fixed-form exercise. In general, 30% of 1RM will elicit peak power outputs for both genders and all exercises used in this study, allowing this standard percentage to be used as a starting point in order to train maximal mechanical power output capabilities in these lifts in strength trained athletes.


Journal of Strength and Conditioning Research | 2008

Effects of Stretching on Upper-body Muscular Performance

Earlando M Torres; William J. Kraemer; Jakob L. Vingren; Jeff S. Volek; Disa L. Hatfield; Barry A. Spiering; Jen Yu Ho; Maren S. Fragala; Gwendolyn A. Thomas; Jeffrey M. Anderson; Keijo Häkkinen; Carl M. Maresh

Torres, EM, Kraemer, WJ, Vingren, JL, Volek, JS, Hatfield, DL, Spiering, BA, Ho, JY, Fragala, MS, Thomas, GA, Anderson, JM, Häkkinen, K, and Maresh, CM. Effects of stretching on upper-body muscular performance. J Strength Cond Res 22: 1279-1285, 2008-The purpose of this investigation was to examine the influence of upper-body static stretching and dynamic stretching on upper-body muscular performance. Eleven healthy men, who were National Collegiate Athletic Association Division I track and field athletes (age, 19.6 ± 1.7 years; body mass, 93.7 ± 13.8 kg; height, 183.6 ± 4.6 cm; bench press 1 repetition maximum [1RM], 106.2 ± 23.0 kg), participated in this study. Over 4 sessions, subjects participated in 4 different stretching protocols (i.e., no stretching, static stretching, dynamic stretching, and combined static and dynamic stretching) in a balanced randomized order followed by 4 tests: 30% of 1 RM bench throw, isometric bench press, overhead medicine ball throw, and lateral medicine ball throw. Depending on the exercise, test peak power (Pmax), peak force (Fmax), peak acceleration (Amax), peak velocity (Vmax), and peak displacement (Dmax) were measured. There were no differences among stretch trials for Pmax, Fmax, Amax, Vmax, or Dmax for the bench throw or for Fmax for the isometric bench press. For the overhead medicine ball throw, there were no differences among stretch trials for Vmax or Dmax. For the lateral medicine ball throw, there was no difference in Vmax among stretch trials; however, Dmax was significantly larger (p ≤ 0.05) for the static and dynamic condition compared to the static-only condition. In general, there was no short-term effect of stretching on upper-body muscular performance in young adult male athletes, regardless of stretch mode, potentially due to the amount of rest used after stretching before the performances. Since throwing performance was largely unaffected by static or dynamic upper-body stretching, athletes competing in the field events could perform upper-body stretching, if enough time were allowed before the performance. However, prior studies on lower-body musculature have demonstrated dramatic negative effects on speed and power. Therefore, it is recommended that a dynamic warm-up be used for the entire warm-up.


Medicine and Science in Sports and Exercise | 2009

Effects of amino acids supplement on physiological adaptations to resistance training

William J. Kraemer; Disa L. Hatfield; Jeff S. Volek; Maren S. Fragala; Jakob L. Vingren; Jeffrey M. Anderson; Barry A. Spiering; Gwendolyn A. Thomas; Jen Yu Ho; Erin E. Quann; Mikel Izquierdo; Keijo Häkkinen; Carl M. Maresh

INTRODUCTION Previous research has demonstrated that ingestion of essential amino acids and their metabolites induce anabolic effects with the potential to augment gains in lean body mass and strength after resistance exercise training. PURPOSE The purpose of the present study was to examine the effects of an essential amino acid-based formula (Muscle Armor (MA); Abbott Laboratories, Abbott Park, IL) containing beta-hydroxy-beta-methylbutyrate (HMB) on hormonal and muscle damage markers in response to 12 wk of resistance exercise. METHODS Seventeen healthy men (mean body mass: 77.9 +/- 7.2 kg; mean height: 174.3 +/- 12.4 cm; mean age: 22.9 +/- 3.8 yr) were matched and randomized into two groups and performed 12 wk of periodized heavy resistance training while supplementing with either MA or an isocaloric, isonitrogenous placebo (CON). Every 2 wk during the 12-wk intervention, resting blood draws were obtained, and muscle strength and power were measured. In addition, blood draws were obtained before, during, and after a standardized resistance exercise challenge performed pre-, mid-, and posttraining. RESULTS Lean body mass, muscle strength, and muscle power significantly (P <or= 0.05) increased in both groups after training; however, MA supplementation augmented these responses to a significantly greater extent when compared with the CON group. MA supplementation promoted increases in resting and exercise-induced testosterone and resting growth hormone concentrations. In addition, MA reduced preexercise cortisol concentrations. Throughout the training protocol, MA attenuated circulating creatine kinase and malondealdehyde compared with the CON group, suggesting that MA might have influenced a reduction in muscle damage. CONCLUSION MA supplementation beneficially affected training-induced changes in lean body mass, muscle strength, and power, as well as hormonal responses and markers of muscle damage in response to 12 wk of resistance exercise training when compared with an isonitrogenous control.


Journal of Strength and Conditioning Research | 2009

Recovery from a national collegiate athletic association division I football game: muscle damage and hormonal status.

William J. Kraemer; Barry A. Spiering; Jeff S. Volek; Gerard J. Martin; Robert Howard; Nicholas A. Ratamess; Disa L. Hatfield; Jakob L. Vingren; Jen Yu Ho; Maren S. Fragala; Gwendolyn A. Thomas; Duncan N. French; Jeffrey M. Anderson; Keijo Häkkinen; Carl M. Maresh

Kraemer, WJ, Spiering, BA, Volek, JS, Martin, GJ, Howard, RL, Ratamess, NA, Hatfield, DL, Vingren, JL, Ho, JY, Fragala, MS, Thomas, GA, French, DN, Anderson, JM, Häkkinen, K, and Maresh, CM. Recovery from a National Collegiate Athletic Association Division I football game: muscle damage and hormonal status. J Strength Cond Res 23(1): 2-10, 2009-Recovery from an American football game has had limited study. The purpose of this study was to examine markers of skeletal muscle tissue damage and circulating anabolic and catabolic hormones to gain insight into the recovery process from Friday until Monday, when a new practice week begins. Twenty-eight National Collegiate Athletic Association Division I football players gave consent to participate in the investigation in the ninth game of the season. Sixteen players started the game and played the entire game (PL), and 12 others did not play and were on the bench during the game (DNP). Each player had fasted blood samples obtained at the same time of day between 1000 and 1200 hours the day before the game (Friday; T1), 18-20 hours after the game (Sunday; T2), and then 42-44 hours after the game (Monday; T3). Blood samples were analyzed for concentrations of creatine kinase (CK), lactate dehydrogenase (LDH), myoglobin, testosterone, and cortisol. The PL players showed significantly (p ≤ 0.05) increased concentrations of CK (T2 > T1 and T3), myoglobin (T2 > T1 and T3), and LDH (T2 > T1). In contrast, DNP players showed significant differences in cortisol (T3 < T1 and T2) and testosterone:cortisol (T3 > T1). Few changes were observed in testosterone and cortisol changes, indicating stability of the anabolic/catabolic hormones. In conclusion, these data indicate that participation in a college football game late in the season results in some degree of tissue damage but with minimal hormonal responses, which seem to have stabilized at resting concentrations without predominance of cortisols catabolic presence. As previously noted in the literature, some type of “contact adaptation” to the season may have occurred with regard to tissue damage responses. However, by the ninth game of a season, players do carry soft tissue damage levels above resting ranges into subsequent games, indicating that recovery should be monitored, with coaches being careful with scheduling scrimmage and full-contact drills. How such data implicate overuse injuries remains unclear, considering that hormonal status in this study was highly stable, with catabolic influences minimized by the high level of athlete conditioning. These data again support that high-level conditioning can stabilize anabolic and catabolic hormonal signals and limit acute soft tissue injury, making cerebral concussion (acute and chronic) and traumatic injury the biggest threats to a student-athletes health and well-being during an American football game.


Cancer Prevention Research | 2013

Effect of exercise on markers of inflammation in breast cancer survivors: the Yale exercise and survivorship study.

Sara B. Jones; Gwendolyn A. Thomas; Sara D. Hesselsweet; Marty Alvarez-Reeves; Herbert Yu; Melinda L. Irwin

Physical activity is associated with improved breast cancer survival, but the underlying mechanisms, possibly including modification of the inflammatory state, are not well understood. We analyzed changes in interleukin (IL)-6, C-reactive protein (CRP), and TNF-α in a randomized controlled trial of exercise in postmenopausal breast cancer survivors. Seventy-five women, recruited through the Yale-New Haven Hospital Tumor Registry, were randomized to either a six-month aerobic exercise intervention or usual care. Correlations were calculated between baseline cytokines, adiposity, and physical activity measures. Generalized linear models were used to assess the effect of exercise on IL-6, CRP, and TNF-α. At baseline, IL-6 and CRP were positively correlated with body fat and body mass index (BMI) and were inversely correlated with daily pedometer steps (P < 0.001). We found no significant effect of exercise on changes in inflammatory marker concentrations between women randomized to exercise versus usual care, though secondary analyses revealed a significant reduction in IL-6 among exercisers who reached 80% of the intervention goal compared with those who did not. Future studies should examine the effect of different types and doses of exercise and weight loss on inflammatory markers in large-scale trials of women diagnosed with breast cancer. Cancer Prev Res; 6(2); 109–18. ©2012 AACR.


Steroids | 2009

Effect of resistance exercise on muscle steroid receptor protein content in strength-trained men and women

Jakob L. Vingren; William J. Kraemer; Disa L. Hatfield; Jeff S. Volek; Nicholas A. Ratamess; Jeffrey M. Anderson; Keijo Häkkinen; Juha P. Ahtiainen; Maren S. Fragala; Gwendolyn A. Thomas; Jen Yu Ho; Carl M. Maresh

The purpose of this study was to examine the acute effect of resistance exercise (RE) on muscle androgen receptor (AR) and glucocorticoid receptor (GR) protein content. Fifteen resistance-trained men (n=8; 21+/-1 years, 175.3+/-6.7 cm, 90.8+/-11.6 kg) and women (n=7; 24+/-5 years, 164.6+/-6.7 cm, 76.4+/-15.6 kg) completed 6 sets of 10 repetitions of heavy squats. Blood samples were obtained before RE, after 3 and 6 sets of squats, and 5, 15, 30 and 70 min after RE. Muscle biopsies from the vastus lateralis were obtained before RE, and 10 min and 70 min after RE. Blood samples were analyzed for total and free testosterone concentrations and muscle samples were analyzed for AR and GR protein content. Circulating total testosterone increased significantly (p< or =0.05) in men and free testosterone increased in men and women with exercise. AR was significantly reduced at 70 min post-exercise in men and at 10 min post-exercise in women compared to pre-exercise. There were no changes in GR following RE, but GR was significantly higher in women compared to men. These findings support a current paradigm for stabilization followed by a reduction and then a rebound in the acute AR response to RE but demonstrate that gender differences exist in the timeline of the AR response.


Journal of Applied Physiology | 2008

Effect of resistance exercise on muscle steroidogenesis

Jakob L. Vingren; William J. Kraemer; Disa L. Hatfield; Jeffrey M. Anderson; Jeff S. Volek; Nicholas A. Ratamess; Gwendolyn A. Thomas; Jen Yu Ho; Maren S. Fragala; Carl M. Maresh

Circulating testosterone is elevated acutely following resistance exercise (RE) and is an important anabolic hormone for muscle adaptations to resistance training. The purpose of this study was to examine the acute effect of heavy RE on intracrine muscle testosterone production in young resistance-trained men and women. Fifteen young, highly resistance-trained men (n = 8; 21 +/- 1 yr, 175.3 +/- 6.7 cm, 90.8 +/- 11.6 kg) and women (n = 7; 24 +/- 5 yr, 164.6 +/- 6.7 cm, 76.4 +/- 15.6 kg) completed 6 sets of 10 repetitions of Smith machine squats with 80% of their 1-repetition maximum. Before RE and 10 and 70 min after RE, muscle biopsies were obtained from the vastus lateralis. Before RE, after 3 and 6 sets of squats, and 5, 15, 30, and 70 min into recovery from RE, blood samples were obtained using venipuncture from an antecubital vein. Muscle samples were analyzed for testosterone, 17beta-hydroxysteroid dehydrogenase (HSD) type 3, and 3beta-HSD type 1 and 2 content. Blood samples were analyzed for glucose and lactate concentrations. No changes were found for muscle testosterone, 3beta-HSD type 1 and 2, and 17beta-HSD type 3 concentrations. However, a change in protein migration in the Bis-Tris gel was observed for 17beta-HSD type 3 postexercise; this change in migration indicated an approximately 2.8 kDa increase in molecular mass. These findings indicate that species differences in muscle testosterone production may exist between rats and humans. In humans, muscle testosterone concentrations do not appear to be affected by RE. This study expands on the current knowledge obtained from animal studies by examining resting and postexercise concentrations of muscle testosterone and steroidogenic enzymes in humans.


Current Sports Medicine Reports | 2010

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

William J. Kraemer; Courtenay Dunn-Lewis; Brett A. Comstock; Gwendolyn A. Thomas; James E. Clark; Bradley C. Nindl

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.


Journal of Strength and Conditioning Research | 2010

Endocrine response patterns to acute unilateral and bilateral resistance exercise in men

Matthew J. Migiano; Jakob L. Vingren; Jeff S. Volek; Carl M. Maresh; Maren S. Fragala; Jen Yu Ho; Gwendolyn A. Thomas; Disa L. Hatfield; Keijo Häkkinen; Juha P. Ahtiainen; Jacob E. Earp; William J. Kraemer

Migiano, MJ, Vingren, JL, Volek, JS, Maresh, CM, Fragala, MS, Ho, J-Y, Thomas, GA, Hatfield, DL, Häkkinen, K, Ahtiainen J, Earp, JE, and Kraemer WJ. Endocrine response patterns to acute unilateral and bilateral resistance exercise in men. J Strength Cond Res 24(1): 128-134, 2010-Rehabilitation programs and research experiments use single-arm protocols in which the contralateral arm is not functional or used as a control limb. This study was interested in determining the hormonal signal impacts of such one- versus two-arm exercise responses that might have an impact on adaptational changes with training. The purpose was to examine the acute hormonal responses to a unilateral and a bilateral upper-body resistance exercise (RE) protocol. A balanced randomized treatment intervention with series time frame for blood collections before and after exercise was used as the basic experimental design. Ten recreationally resistance trained men (18-25 years, 20.4 ± 1.2 years, 175.6 ± 4.5 cm, 81.7 ± 9.3 kg) gave informed consent to participate in the investigation. Each subject performed unilateral (dominant arm only) and bilateral upper-body RE protocol separated by 1 week in a balanced randomized fashion. The RE protocol consisted of 3 sets of 10 repetitions of 5 different dumbbell upper-body exercises at 80% of 1-repetition maximum, and blood samples were obtained before and 5, 15, and 30 minutes immediately postexercise (IP). Blood was obtained and analyzed for lactate, immunoreactive growth hormone (iGH), cortisol (C), total testosterone (T), and insulin concentrations. Total volume of work also was determined for the 2 exercise sessions. Total volume of work performed during the unilateral protocol was 52.1% of that for the bilateral protocol. Both RE protocols elicited a significant (p ≤ 0.05) increase in lactate and iGH, but the increase for the bilateral condition was significantly greater. Cortisol decreased significantly during recovery for the unilateral condition. Testosterone was not affected by either protocol. Insulin was significantly increased at IP and 5 minutes postexercise for both conditions. These results indicate that the hormonal responses to dominant-arm unilateral RE is blunted compared to that for bilateral RE. This differential endocrine response is likely a result of the difference in volume between the protocols. It is important to pay attention to the amount of muscle mass utilized in a resistance exercise protocol to optimize endocrine signaling.

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Maren S. Fragala

University of Central Florida

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Disa L. Hatfield

University of Rhode Island

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Jen Yu Ho

University of Connecticut

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Keijo Häkkinen

University of Jyväskylä

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