David H. Fukuda

Dr. David H. Fukuda

School of Kinesiology and Physical Therapy, University of Central Florida, Orlando, FL 32816, USA
orcid

Research Focus & Metrics

Academic Career Length

18Years (2009-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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13 August 2015 in Physiological Reports
Verified
Journal Article
Open access
PDF file
GMGerald T. Mangine
Gerald T. Mangine
JHJay Hoffman
Jay Hoffman
AGAdam M. Gonzalez
Adam M. Gonzalez
JTJeremy Townsend
Jeremy Townsend
Adam WellsAdam Wells
Adam Wells
Jeffrey StoutJeffrey Stout
Jeffrey Stout
This investigation compared the effect of high‐volume (VOL) versus high‐intensity (INT) resistance training on stimulating changes in muscle size and strength in resistance‐trained men. Following a 2‐week preparatory phase, participants were randomly assigned to either a high‐volume (VOL; n = 14, 4 × 10–12 repetitions with ~70% of one repetition maximum [1RM], 1‐min rest intervals) or a high‐intensity (INT; n = 15, 4 × 3–5 repetitions with ~90% of 1RM, 3‐min rest intervals) training group for 8 weeks. Pre‐ and posttraining assessments included lean tissue mass via dual energy x‐ray absorptiometry, muscle cross‐sectional area and thickness of the vastus lateralis (VL), rectus femoris (RF), pectoralis major, and triceps brachii muscles via ultrasound images, and 1RM strength in the back squat and bench press (BP) exercises. Blood samples were collected at baseline, immediately post, 30 min post, and 60 min postexercise at week 3 (WK3) and week 10 (WK10) to assess the serum testosterone, growth hormone (GH), insulin‐like growth factor‐1 (IGF1), cortisol, and insulin concentrations. Compared to VOL, greater improvements ( P < 0.05) in lean arm mass (5.2 ± 2.9% vs. 2.2 ± 5.6%) and 1RM BP (14.8 ± 9.7% vs. 6.9 ± 9.0%) were observed for INT. Compared to INT, area under the curve analysis revealed greater ( P < 0.05) GH and cortisol responses for VOL at WK3 and cortisol only at WK10. Compared to WK3, the GH and cortisol responses were attenuated ( P < 0.05) for VOL at WK10, while the IGF1 response was reduced ( P < 0.05) for INT. It appears that high‐intensity resistance training stimulates greater improvements in some measures of strength and hypertrophy in resistance‐trained men during a short‐term training period.

1 November 2016 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
RWRan Wang
Ran Wang
JHJay Hoffman
Jay Hoffman
STSatoru Tanigawa
Satoru Tanigawa
AMAmelia A. Miramonti
Amelia A. Miramonti
MMMichael B. La Monica
Michael B. La Monica
Jeffrey StoutJeffrey Stout
Jeffrey Stout
Wang, R, Hoffman, JR, Tanigawa, S, Miramonti, AA, La Monica, MB, Beyer, KS, Church, DD, Fukuda, DH, and Stout, JR. Isometric mid-thigh pull correlates with strength, sprint, and agility performance in collegiate rugby union players. J Strength Cond Res 30(11): 3051–3056, 2016—The purpose of this investigation was to examine the relationships between isometric mid-thigh pull (IMTP) force and strength, sprint, and agility performance in collegiate rugby union players. Fifteen members of a champion-level university's club rugby union team (mean ± SD: 20.67 ± 1.23 years, 1.78 ± 0.06 m, and 86.51 ± 14.18 kg) participated in this investigation. One repetition maximum (1RM) squat, IMTP, speed (40 m sprint), and agility (proagility test and T-test) were performed during 3 separate testing sessions. Rate of force development (RFD) and force output at 30, 50, 90, 100, 150, 200, and 250 milliseconds of IMTP, as well as the peak value were determined. Pearson product-moment correlation analysis was used to examine the relationships between these measures. Performance in the 1RM squat was significantly correlated to the RFD between 90 and 250 milliseconds from the start of contraction (r's ranging from 0.595 to 0.748), and peak force (r = 0.866, p ≤ 0.05). One repetition maximum squat was also correlated to force outputs between 90 and 250 milliseconds (r's ranging from 0.757 to 0.816, p ≤ 0.05). Sprint time over the first 5 m in the 40 m sprint was significantly (p ≤ 0.05) correlated with peak RFD (r = −0.539) and RFD between 30 and 50 milliseconds (r's = −0.570 and −0.527, respectively). Time for the proagility test was correlated with peak RFD (r = −0.523, p ≤ 0.05) and RFD between 30 and 100 milliseconds (r's ranging from −0.518 to −0.528, p's < 0.05). Results of this investigation indicate that IMTP variables are significantly associated with strength, agility, and sprint performance. Future studies should examine IMTP as a potential tool to monitor athletic performance during the daily training of rugby union players.

1 May 2014 in Journal of Strength & Conditioning Research
Verified
Journal Article
Closed access
EFEmerson Franchini
Emerson Franchini
CBCiro Jose Brito
Ciro Jose Brito
David H. FukudaDavid H. Fukuda
David H. Fukuda
GAGuilherme Artioli
Guilherme Artioli
Understanding the physiological response to the most common judo training modalities may help to improve the prescription and monitoring of training programs. This review is based on search results using the following terms: "judo," "judo and training," "judo and physiology," "judo and specific exercises," and "judo and combat practice." Uchi-komi (repetitive technical training) is a specific judo exercise that can be used to improve aerobic and anaerobic fitness. Effort to pause ratio, total session duration, number and duration of individual sets, and the type of technique can be manipulated to emphasize specific components of metabolism. "Nage-komi" (repetitive throwing training) can also be used to improve aerobic and anaerobic fitness, depending on the format of the training session. "Randori" (combat or fight practice; sparring) is the training modality most closely related to actual judo matches. Despite the similarities, the physiological demands of randori practice are not as high as observed during real competitive matches. Heart rate has not shown to be an accurate measure of training intensity during any of the previously mentioned judo training modalities. High-volume, high-intensity training programs often lead judo athletes to experience overtraining-related symptoms, with immunosuppression being one of the most common. In conclusion, judo training and judo-specific exercise should be manipulated to maximize training response and competitive performance.

1 November 2013 in Experimental Gerontology
Verified
Journal Article
Open access
Jeffrey StoutJeffrey Stout
Jeffrey Stout
ASAbbie E Smith-Ryan
Abbie E Smith-Ryan
David H. FukudaDavid H. Fukuda
David H. Fukuda
KKKristina L. Kendall
Kristina L. Kendall
JMJordan R. Moon
Jordan R. Moon
VMVikkie A. Mustad
Vikkie A. Mustad
Evidence suggests CaHMB may impact muscle mass and/or strength in older adults, yet no long-term studies have compared its effectiveness in sedentary and resistance training conditions. The purpose of this study was to evaluate the effects of 24 weeks of CaHMB supplementation and resistance training (3 d wk(-1)) or CaHMB supplementation only in ≥65 yr old adults. This double-blinded, placebo-controlled, trial occurred in two phases under ad libitum conditions. Phase I consisted of two non-exercise groups: (a) placebo and (b) 3 g CaHMB consumed twice daily. Phase II consisted of two resistance exercise groups: (a) placebo and resistance exercise and (b) 3 g CaHMB consumed twice daily and resistance exercise (RE). Strength and functionality were assessed in both phases with isokinetic leg extension and flexion at 60°·s(-1) and 180°·s(-1) (LE60, LF60, LE180, LF180), hand grip strength (HG) and get-up-and-go (GUG). Dual X-Ray Absorptiometry (DXA) was used to measure arm, leg, and total body lean mass (LM) as well as total fat mass (FM). Muscle Quality was measured for arm (MQ(HG)=HG/arm LM) and Leg (MQ60=LE60/leg LM) (MQ180=LE180/leg LM). At 24 weeks of Phase I, change in LE60 (+8.8%) and MQ180 (+20.8%) for CaHMB was significantly (p<0.05) greater than that for placebo group. Additionally, only CaHMB showed significant (p<0.05) improvements in total LM (2.2%), leg LM (2.1%), and LE180 (+17.3%), though no treatment effect was observed. Phase II demonstrated that RE significantly improved total LM (4.3%), LE60 (22.8%), LE180 (21.4%), HG (9.8%), and GUG (10.2%) with no difference between treatment groups. At week 24, only CaHMB group significantly improved FM (-3.8%) and MQHG (7.3%); however there was no treatment main effect for these variables. CaHMB improved strength and MQ without RE. Further, RE is an effective intervention for improving all measures of body composition and functionality.

1 September 2013 in International Journal of Sports Physiology and Performance
Verified
Journal Article
Closed access
PDF file
LRLindy M. Rossow
Lindy M. Rossow
David H. FukudaDavid H. Fukuda
David H. Fukuda
CFChristopher A. Fahs
Christopher A. Fahs
JLJeremy P. Loenneke
Jeremy P. Loenneke
Jeffrey StoutJeffrey Stout
Jeffrey Stout
Bodybuilding is a sport in which competitors are judged on muscular appearance. This case study tracked a drug-free male bodybuilder (age 26–27 y) for the 6 mo before and after a competition.Purpose: The aim of this study was to provide the most comprehensive physiological profile of bodybuilding competition preparation and recovery ever compiled.Methods: Cardiovascular parameters, body composition, strength, aerobic capacity, critical power, mood state, resting energy expenditure, and hormonal and other blood parameters were evaluated.Results: Heart rate decreased from 53 to 27 beats/min during preparation and increased to 46 beats/min within 1 mo after competition. Brachial blood pressure dropped from 132/69 to 104/56 mmHg during preparation and returned to 116/64 mmHg at 6 mo after competition. Percent body fat declined from 14.8% to 4.5% during preparation and returned to 14.6% during recovery. Strength decreased during preparation and did not fully recover during 6 months of recovery. Testosterone declined from 9.22 to 2.27 ng/mL during preparation and returned back to the baseline level, 9.91 ng/mL, after competition. Total mood disturbance increased from 6 to 43 units during preparation and recovered to 4 units 6 mo after competition.Conclusions: This case study provides a thorough documentation of the physiological changes that occurred during natural bodybuilding competition and recovery.

26 May 2016 in Journal of Applied Physiology
Verified
Journal Article
Open access
PDF file
DCDavid D. Church
David D. Church
JHJay Hoffman
Jay Hoffman
GMGerald T. Mangine
Gerald T. Mangine
AJAdam R. Jajtner
Adam R. Jajtner
JTJeremy Townsend
Jeremy Townsend
JSJeffrey R. Stout
Jeffrey R. Stout
This study compared the acute and chronic response of circulating plasma brain-derived neurotrophic factor (BDNF) to high-intensity low-volume (HI) and low-intensity high volume (HV) resistance training. Twenty experienced resistance trained men (23.5±2.6 y, 1.79±0.05 m, 75.7±13.8 kg) volunteered for this study. Prior to the resistance training program (PRE), participants performed an acute bout of exercise using either the HI (3-5 reps; 90% of one repetition maximum [1RM]) or HV (10-12 reps; 70% 1RM) training paradigm. The acute exercise protocol was repeated following 7-weeks of training (POST). Blood samples were obtained at rest (BL), immediately- (IP), 30-min (30P) and 60-min (60P) post exercise at PRE and POST. A 3-way repeated measure ANOVA was used to analyze acute changes in BDNF concentrations during HI and HV resistance exercise at PRE and POST. No training x time x group interaction in BDNF was noted (p=0.994). Significant main effects for training (p=0.050) and time (p<0.001) in BDNF were observed. Significant elevations in BDNF concentrations were seen from BL at IP (p=0.001), 30P (p<0.001), and 60P (p<0.001) in both HI and HV combined during PRE and POST. BDNF concentrations were also observed to increase from PRE to POST when collapsed across groups and time. No significant group x training interaction (p=0.342), training (p=0.105), or group (p=0.238) effect were noted in the BDNF area under the curve response. Results indicate BDNF concentrations are increased after an acute bout of resistance exercise, regardless of training paradigm, and are further increased during a 7-week training program in experienced lifters.