Todd A Trappe

Ball State University, Muncie, Indiana, United States

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Publications (136)450.94 Total impact

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    ABSTRACT: Common cyclooxygenase (COX)-inhibiting drugs enhance resistance exercise induced muscle mass and strength gains in older individuals. The purpose of this investigation was to determine whether the underlying mechanism regulating this effect was specific to Type I or Type II muscle fibers, which have different contractile and metabolic profiles. Muscle biopsies (vastus lateralis) were obtained before and after 12 weeks of knee-extensor resistance exercise (3 days/week) from healthy older men who consumed either a placebo (n = 8; 64±2 years) or COX inhibitor (acetaminophen, 4 gram/day; n = 7; 64±1 years) in double-blind fashion. Muscle samples were examined for Type I and II fiber cross-sectional area, capillarization, and metabolic enzyme activities (glycogen phosphorylase, citrate synthase, β-hydroxyacyl-CoA-dehydrogenase). Type I fiber size did not change with training in the placebo group (304±590 μm2) but increased 28% in the COX inhibitor group (1,388±760 μm2, p < .1). Type II fiber size increased 26% in the placebo group (1,432±499 μm2, p < .05) and 37% in the COX inhibitor group (1,825±400 μm2, p < .05). Muscle capillarization and enzyme activity were generally maintained in the placebo group. However, capillary to fiber ratio increased 24% (p < .1) and citrate synthase activity increased 18% (p < .05) in the COX inhibitor group. COX inhibitor consumption during resistance exercise in older individuals enhances myocellular growth, and this effect is more pronounced in Type I muscle fibers.
    No preview · Article · Jan 2016 · The Journals of Gerontology Series A Biological Sciences and Medical Sciences
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    ABSTRACT: Prostaglandin E2 (PGE2) produced by the cyclooxygenase (COX) pathway regulates skeletal muscle protein turnover and exercise training adaptations. The purpose of this study was two-fold: 1) Define the PGE2/COX pathway enzymes and receptors in human skeletal muscle, with a focus on Type I and II muscle fibers, 2) Examine the influence of aging on this pathway. Muscle biopsies were obtained from the soleus (primarily Type I fibers) and vastus lateralis (proportionally more Type II fibers than soleus) of young men and women (n=8, 26±2y), and from the vastus lateralis of young (n=8; 25±1y) and old (n=12; 79±2y) men and women. PGE2/COX pathway proteins [COX enzymes (COX-1, COX-2), PGE2 synthases (cPGES, mPGES-1, mPGES-2), and PGE2 receptors (EP1, EP2, EP3, EP4)] were quantified via Western blot. COX-1, cPGES, mPGES-2, and all four PGE2 receptors were detected in all skeletal muscle samples examined. COX-1 (P<0.1) and mPGES-2 were ~20% higher, while EP3 was 99% higher and EP4 57% lower in soleus compared to vastus lateralis (P<0.05). Aging did not change the level of skeletal muscle COX-1, while cPGES increased 45% and EP1 (P<0.1), EP3, and EP4 decreased ~33% (P<0.05). In summary, PGE2 production capacity and receptor levels are different in human skeletal muscles with markedly different Type I and II muscle fiber composition. In aging skeletal muscle, PGE2 production capacity is elevated and receptor levels are downregulated. These findings have implications for understanding the regulation of skeletal muscle adaptations to exercise and aging by the PGE2/COX pathway and related inhibitors.
    No preview · Article · Nov 2015 · Journal of Applied Physiology
  • P T Reidy · J M Hinkley · T A Trappe · S W Trappe · M P Harber
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    ABSTRACT: Evidence suggests that myofibers from endurance trained skeletal muscle display unique contractile parameters. However, the underlying mechanisms remain unclear. To further elucidate the influence of endurance training on myofiber contractile function, we examined factors that may impact myofilament interactions (i. e., water content, concentration of specific protein fractions, actin and myosin content) or directly modulate myosin heavy chain (MHC) function (i. e., myosin light chain (MLC) composition) in muscle biopsy samples from highly-trained competitive (RUN) and recreational (REC) runners. Muscle water content was lower (P<0.05) in RUN (73±1%) compared to REC (75±1%) and total muscle and myofibrillar protein concentration was higher (P<0.05) in RUN, which may indicate differences in myofilament spacing. Content of the primary contractile proteins, myosin (0.99±0.08 and 1.01±0.07 AU) and actin (1.33±0.09 and 1.27±0.09 AU) in addition to the myosin to actin ratio (0.75±0.04 and 0.80±0.06 AU) was not different between REC and RUN, respectively, when expressed relative to the amount of myofibrillar protein. At the single-fiber level, slow-twitch MHC I myofibers from RUN contained less (P<0.05) MLC 1 and greater (P<0.05) amounts of MLC 3 than REC, while MLC composition was similar in fast-twitch MHC IIa myofibers between REC and RUN. These data suggest that the distinctive myofiber contractile profile in highly-trained runners may be partially explained by differences in the content of the primary contractile proteins and provides unique insight into the modulation of contractile function with extreme loading -patterns.
    No preview · Article · Nov 2013 · International Journal of Sports Medicine
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    ABSTRACT: Introduction: We examined if epinephrine in the local anesthetic to help control incision-related bleeding interferes with molecular measurements obtained with the Duchenne-Bergström percutaneous needle biopsy technique for sampling human skeletal muscle. Methods: Three groups received 2.5-3.0 ml of 1% lidocaine in 2 injections: (1) 0.5-1.0 ml superficially, which varied among the groups according to (i) -Epi; intra- and subcutaneous without epinephrine, (ii) +Epi -Fascia; intra- and subcutaneous with epinephrine, avoiding the fascia, and (iii) +Epi +Fascia; intra- and subcutaneous with epinephrine, directing a small amount (∽0.2 ml) into the fascia area; and (2) ∽2.0 ml without epinephrine into the fascia area for all subjects. A muscle biopsy was obtained 5-10 min later for IL-6 and MuRF-1 mRNA levels. Results: IL-6 mRNA levels were low in -Epi and +Epi -Fascia, but ∽300-fold higher in +Epi +Fascia. MuRF-1 mRNA levels were similar among the groups. Conclusions: Lidocaine with epinephrine can confound intramuscular measurements from needle biopsies, but this can be avoided with a careful injection approach.
    No preview · Article · Oct 2013 · Muscle & Nerve
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    ABSTRACT: Studies of real and simulated microgravity exposure show the lower limb muscles atrophy to the greatest extent, with the calf muscles being most affected and most difficult to target with exercise countermeasures. This ground-based study examined the metabolic involvement of the thigh and calf muscles during two cycle exercise protocols (moderate and high intensity) central to the exercise countermeasures program on the International Space Station. Intramuscular glycogen and triglyceride levels were quantified in the vastus lateralis and soleus muscles before and after a moderate (current ISS prescription: 45 min at 55% VO(2max), 131 +/- 12 W) and high (proposed ISS prescription: 8 x 30-s intervals at 150% VO(2max), 459 +/- 34 W) intensity cycle exercise bout in nine individuals. During moderate intensity cycling, glycogen was significantly reduced in the vastus lateralis (114 +/- 27 mmol x kg(-1) dry weight) and remained unchanged in the soleus. High intensity cycling significantly reduced glycogen in both muscles, but the vastus lateralis (151 +/- 25 mmol x kg(-1) dry weight) used significantly more (-160%) than the soleus (59 +/- 11 mmol x kg(-1) dry weight). Intramuscular triglycerides were unchanged in both muscles at both intensities. These findings, coupled with other ground-based studies, provide strong support for high intensity cycling being a more appropriate component of the ISS prescription for upper and lower leg skeletal muscle health and cardiorespiratory fitness, although additional exercise paradigms that target the calf are warranted. These muscle-specific findings should be considered when designing exercise strategies for combating conditions of sarcopenia and muscle wasting on Earth.
    No preview · Article · Aug 2013 · Aviation Space and Environmental Medicine
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    ABSTRACT: Exercise and nutritional interventions have been examined independently as countermeasures to offset the loss of skeletal muscle mass with unloading, yet a protocol to completely preserve the soleus has not been identified. Little is known regarding the combined effect of exercise and nutrition on factors regulating skeletal muscle growth. The purpose of this investigation was to evaluate the influence of amino acid (AA) infusion on myogenic (MRF-4, MyoD, and Myogenin), proteolytic (MuRF-1, Atrogin-1, FOXO3A, Calpain-1, Calpain-2, Caspase-3, Cathepsin L1), and cytokine (IL-6, IL-8, and IL-15) mRNA transcripts in two skeletal muscles that respond distinctly to microgravity unloading. Muscle biopsies were obtained from the vastus lateralis (VL) and soleus of eight male subjects prior to and after 4 h of AA infusion for analysis of mRNA expression. All subjects performed a standardized exercise bout (45-min treadmill run) 24 h prior to the AA infusion. In the VL, proteolytic factors MuRF-1 and FOXO3A were reduced (44 +/- 9 and 28 +/- 6%, respectively) in response toAA infusion. In the soleus, mRNA transcripts of myogenic factor MRF-4 (91 +/- 36%) and cytokines IL-6, IL-8, and IL-15 were elevated while the proteolytic marker FOXO3A mRNA was reduced by 19 +/- 9%. These data suggest that the expression of genes related to skeletal muscle remodeling is altered during acute AA infusion 24 h post-exercise. It appears that increased amino acid availability in concert with exercise may create an intramuscular environment favorable for the prevention of muscle atrophy associated with unloading, which may be particularly beneficial for the soleus.
    No preview · Article · Jul 2013 · Aviation Space and Environmental Medicine
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    Todd A Trappe · Sophia Z Liu
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    ABSTRACT: It has been ~40 years since the discovery that prostaglandins are produced by exercising skeletal muscle, and since the discovery that inhibition of prostaglandin synthesis is the mechanism of action of what are now known as cyclooxygenase (COX)-inhibiting drugs. Since that time, it has been established that prostaglandins are made during and after aerobic and resistance exercise and have a potent paracrine/autocrine effect on muscle metabolism. Consequently, it has also been determined that orally consumed doses of COX-inhibitors can profoundly influence muscle prostaglandin synthesis, muscle protein metabolism, and numerous other cellular processes that regulate muscle adaptations to exercise loading. Although data from acute human exercise studies, as well as animal and cell culture data would predict regular consumption of a COX-inhibitor during exercise training would dampen the typical muscle adaptations, the chronic data do not support this conjecture. From the studies in young and older individuals lasting from 1.5-4 months, no interfering effects of COX-inhibitors on muscle adaptations to resistance exercise training have been noted. In fact, in older individuals a substantial enhancement of muscle mass and strength has been observed. The collective findings of the prostaglandin/COX pathway regulation of skeletal muscle responses and adaptations to exercise are compelling. Considering the discoveries in other areas of COX regulation of health and disease there is certainly an interesting future of investigation in this re-emerging area, especially as it pertains to older individuals and the condition of sarcopenia, as well as exercise training and performance of individuals of all ages.
    Preview · Article · Mar 2013 · Journal of Applied Physiology
  • R.A. Standley · S.Z. Liu · B Jemiolo · S.W. Trappe · T.A. Trappe
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    ABSTRACT: Cyclooxygenase (COX) inhibiting drugs augment muscle mass and strength improvements during resistance exercise based treatment of sarcopenia in older individuals. Initial evidence suggests a potential mechanism of COX inhibitor blunted prostaglandin (PG) E2 stimulation of interleukin (IL)-6 and the ubiquitin ligase MuRF-1, reducing their inhibition on muscle growth. The purpose of this investigation was to determine if PGE2 stimulates IL-6 and MuRF-1 transcription in skeletal muscle. Muscle biopsies were obtained from 10 young individuals and incubated ex vivo with PGE2 or control and analyzed for IL-6 and MuRF-1 mRNA levels. PGE2 upregulated (P<0.05) expression of both IL-6 (195%) and MuRF-1 (51%). A significant relationship was found between IL-6 and MuRF-1 expression after incubation with PGE2 (r=0.77, P<0.05), suggesting regulation through a common pathway. PGE2 induces IL-6 and MuRF-1 transcription in human skeletal muscle, providing a mechanistic link between COX inhibiting drugs, PGE2, and the regulation of muscle mass.
    No preview · Article · Mar 2013 · Prostaglandins Leukotrienes and Essential Fatty Acids
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    ABSTRACT: Twelve weeks of resistance training (3d/wk) combined with daily consumption of the cyclooxygenase-inhibiting drugs acetaminophen (4.0g/d; n=11, 64±1y) or ibuprofen (1.2g/d; n=13, 64±1y) unexpectedly promoted muscle mass and strength gains 25-50% above placebo (n=12, 67±2y). To investigate the mechanism of this adaptation, muscle biopsies obtained before and ~72h following the last training bout were analyzed for mRNA levels of prostaglandin (PG)/COX pathway enzymes and receptors (arachidonic acid synthesis: cPLA(2) and sPLA(2); PGF(2α) synthesis: PGF(2α) synthase and PGE(2) to PGF(2α) reductase; PGE(2) synthesis: PGE(2) synthase-1, -2, and -3; PGF(2α) receptor and PGE(2) receptor-4), cytokines and myokines involved in skeletal muscle adaptation (TNF-α, IL-1β, IL-6, IL-8, IL-10), and regulators of muscle growth (myogenin, MRF4, myostatin) and atrophy (FOXO3A, atrogin-1, MuRF-1, IKKβ). Training increased (P<0.05) cPLA(2), PGF(2α) synthase, PGE(2) to PGF(2α) reductase, PGE(2) receptor-4, TNF-α, IL-1β, IL-8, and IKKβ. However, the PGF(2α) receptor was up-regulated (P<0.05) only in the drug groups and the placebo group up-regulation (P<0.05) of IL-6, IL-10, and MuRF-1 was eliminated in both drug groups. These results highlight prostaglandin and myokine involvement in the adaptive response to exercise in older individuals and suggest two mechanisms underlying the enhanced muscle mass gains in the drug groups: 1) The drug-induced PGF(2α) receptor up-regulation helped offset the drug suppression of PGF(2α)-stimulated protein synthesis after each exercise bout, and enhanced skeletal muscle sensitivity to this stimulation. 2) The drug-induced suppression of intramuscular PGE(2) production increased net muscle protein balance after each exercise bout through a reduction in PGE(2)-induced IL-6 and MuRF-1, both promoters of muscle loss.
    No preview · Article · Dec 2012 · AJP Regulatory Integrative and Comparative Physiology
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    ABSTRACT: We examined whole body aerobic capacity and myocellular markers of oxidative metabolism in lifelong endurance athletes (n=9, 81±1 y, 68±3 kg, BMI=23±1 kg/m(2)) and age-matched, healthy, untrained men (n=6; 82±1 y, 77±5 kg, BMI=26±1 kg/m(2)). The endurance athletes were cross-country skiers, including a former Olympic champion and several national/regional champions, with a history of aerobic exercise and participation in endurance events throughout their lives. Each subject performed a maximal cycle test to assess aerobic capacity (VO(2)max). Subjects had a resting vastus lateralis muscle biopsy to assess oxidative enzymes (citrate synthase and βHAD) and molecular (mRNA) targets associated with mitochondrial biogenesis (PGC-1α and Tfam). The octogenarian athletes had a higher (P<0.05) absolute (2.6±0.1 vs. 1.6±0.1 L•min(-1)) and relative (38±1 vs. 21±1 ml•kg(-1)•min(-1)) VO(2)max, ventilation (79±3 vs. 64±7 L•min(-1)), heart rate (160±5 vs. 146±8 b•min(-1)), and final workload (182±4 vs. 131±14 watts). Skeletal muscle oxidative enzymes were 54% (citrate synthase) and 42% (βHAD) higher (P<0.05) in the octogenarian athletes. Likewise, basal PGC-1α and Tfam mRNA were 135% and 80% greater (P<0.05) in the octogenarian athletes. To our knowledge, the VO(2)max of the lifelong endurance athletes is the highest recorded in humans >80 y of age and comparable to non-endurance trained men 40 years younger. The superior cardiovascular and skeletal muscle health profile of the octogenarian athletes provides a large functional reserve above the aerobic frailty threshold and is associated with lower risk for disability and mortality.
    Full-text · Article · Oct 2012 · Journal of Applied Physiology
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    ABSTRACT: To examine potential age-specific adaptations in skeletal muscle size and myofiber contractile physiology in response to aerobic exercise, seven young (YM; 20±1 yr) and six older (OM; 74±3 yr) men performed 12-weeks of cycle-ergometer training. Muscle biopsies were obtained from the vastus lateralis to determine size and contractile properties of isolated slow (MHC I) and fast (MHC IIa) myofibers. Aerobic capacity was higher (P<0.05) after training in both YM (16±2%) and OM (13±3%). Quadriceps muscle volume, determined via MRI, was 5±1 and 6±1% greater (P<0.05) after training for YM and OM, respectively, which was associated with an increase in MHC I myofiber cross-sectional area (CSA). MHC I peak power was higher (P<0.05) after training for both YM and OM while MHC IIa peak power was increased (P<0.05) with training in OM only. MHC I and MHC IIa myofiber peak and normalized (P(0)/CSA) force were preserved with training in OM while MHC I P(0)/CSA and MHC IIa peak force were lower (P<0.05) after training in YM. These data suggest relative improvements in muscle size and aerobic capacity are similar between young and older men while adaptations in myofiber contractile function showed improvement in OM. Training-related increases in MHC I and MHC IIa peak power reveal that skeletal muscle of OM is responsive to aerobic training and further support the use of aerobic exercise for improving cardiovascular and skeletal muscle health in older individuals.
    No preview · Article · Sep 2012 · Journal of Applied Physiology
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    ABSTRACT: The aim of this project was to develop a method to assess fiber type specific protein content across the continuum of human skeletal muscle fibers. Individual vastus lateralis muscle fibers (n = 264) were clipped into two portions: one for sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) fiber typing and one for Western blot protein identification. Following fiber type determination, fiber segments were combined into fiber type specific pools (∼20 fibers/pool) and measured for total protein quantity, glyceraldehyde 3-phosphate dehydrogenase (GAPDH), citrate synthase (CS), and total p38 content. GAPDH content was 64, 54, 160, and 138% more abundant in myosin heavy chain (MHC) I/IIa, MHC IIa, MHC IIa/IIx, and MHC IIx fibers, respectively, when compared with MHC I. Inversely, CS content was 528, 472, 242, and 47% more abundant in MHC I, MHC I/IIa, MHC IIa, and MHC IIa/IIx fibers, respectively, when compared with MHC IIx. Total p38 content was 87% greater in MHC IIa versus MHC I fibers. These data and this approach establish a reliable method for human skeletal muscle fiber type specific protein analysis. Initial results show that particular proteins exist in a hierarchal fashion throughout the continuum of human skeletal muscle fiber types, further highlighting the necessity of fiber type specific analysis.
    Full-text · Article · Mar 2012 · Analytical Biochemistry
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    ABSTRACT: This investigation examined the effects of acute resistance exercise (RE), progressive resistance training (PRT), and age on the human skeletal muscle Transcriptome. Two cohorts of young and old adults [study A: 24 yr, 84 yr (n = 28); study B: 25 yr, 78 yr (n = 36)] were studied. Vastus lateralis biopsies were obtained pre- and 4 h post-RE in conjunction with the 1st and 36th (last) training session as part of a 12-wk PRT program in study A, whereas biopsies were obtained in the basal untrained state in study B. Additionally, the muscle fiber type specific (MHC I and MHC IIa) Transcriptome response to RE was examined in a subset of young and old women from study A. Transcriptome profiling was performed using HG U133 Plus 2.0 Arrays. The main findings were 1) there were 661 genes affected by RE during the 1st and 36th training bout that correlated with gains in muscle size and strength with PRT (termed the Transcriptome signature of resistance exercise adaptations); 2) the RE gene response was most pronounced in fast-twitch (MHC IIa) muscle fibers and provided additional insight into the skeletal muscle biology affected by RE; 3) skeletal muscle of young adults is more responsive to RE at the gene level compared with old adults and age also affected basal level skeletal muscle gene expression. These skeletal muscle Transcriptome findings provide further insight into the molecular basis of sarcopenia and the impact of resistance exercise at the mixed muscle and fiber type specific level.
    No preview · Article · Feb 2012 · Journal of Applied Physiology
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    ABSTRACT: Human skeletal muscle contains pure myosin heavy chain (MHC) fiber types (I, IIa, and IIx) along with hybrid fibers expressing multiple MHC isoforms (I/IIa, IIa/IIx, and I/IIa/IIx). Although hybrid fibers represent a common component of human muscle, little research exists on their relative MHC protein distribution or single fiber functional profiles. Purpose: Quantify the proportion of co-expressed MHC isoforms in hybrid fibers and determine its influence on single muscle fiber function. Methods: Human muscle fibers (n=68) were isolated from vastus lateralis biopsies, analyzed for single fiber physiology (size, strength, speed, power), typed electrophoretically, digitally imaged, and identified as one of three hybrid fiber types [MHC I/IIa (n=47), MHC IIa/IIx (n=20), and MHC I/IIa/IIx (n=1)]. Two researchers independently quantified (in duplicate) the proportion of MHC isoforms expressed in these fibers via densitometry. Results: Significant correlations in densitometry measures existed between observations from the same researcher (r≥0.995) and different researchers (r=0.998, ICC=0.997), indicating strong test-retest and inter-rater reliability. Proportions of MHC IIa isoform expressed in I/IIa and IIa/IIx hybrid fibers ranged between 7-94% and 28-83% of total MHC protein, respectively. MHC IIa isoform percentage positively correlated with strength (Po, R2=0.40), speed (Vo, R2=0.78), and normalized power (R2=0.76) in MHC I/IIa fibers. No significant correlations were observed between MHC isoform proportions and IIa/IIx hybrid fiber function. Conclusion: These initial results indicate hybrid fibers exist on a morphological and functional continuum. More research is needed to elucidate the physiological significance of hybrid muscle fibers in humans and their adaptability with changes in physical activity patterns. Supported by grants from the National Institutes of Health (AG038576) and the National Aeronautics and Space Administration (NNJ06HF59G).
    No preview · Conference Paper · Jan 2012
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    ABSTRACT: Nine to 12 weeks of resistance exercise training in young individuals induces quadriceps muscle (∼6%) and region-specific patellar tendon (4-6%) hypertrophy. However, 12 weeks of resistance exercise training (∼1 h total exercise time) in older individuals (60-78 years) induces quadriceps muscle hypertrophy (9%) without impacting patellar tendon size. The current study examined if a different loading paradigm using cycle exercise would promote patellar tendon hypertrophy or alter the internal tendon properties, measured with magnetic resonance imaging signal intensity, in older individuals. Nine women (70 ± 2 years) completed 12 weeks of aerobic upright cycle exercise training (∼28 h total exercise time). Aerobic exercise training increased (P < 0.05) quadriceps muscle size (11 ± 2%) and VO(2max) (30 ± 9%). Mean patellar tendon cross-sectional area (CSA) (2 ± 1%) and signal intensity (-1 ± 2%) were unchanged (P > 0.05) over the 12 weeks of training. Region-specific CSA was unchanged (P > 0.05) at the proximal (-1 ± 3%) and mid regions (2 ± 2%) of the tendon but tended (P = 0.069) to increase at the distal region (5 ± 3%). Region-specific signal intensity differed along the tendon but was unchanged (P > 0.05) with training. Although more studies are needed, exercise-induced patellar tendon hypertrophy, compared with skeletal muscle, appears to be attenuated in older individuals, while the loading pattern associated with aerobic exercise seems to have more impact than resistance exercise in promoting patellar tendon hypertrophy.
    No preview · Article · Oct 2011 · Scandinavian Journal of Medicine and Science in Sports
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    ABSTRACT: To assess myosin heavy chain (MHC) plasticity in aging skeletal muscle with aerobic exercise training, MHC composition was measured at the messenger RNA (mRNA) level and protein level in mixed-muscle homogenates and single myofibers. Muscle samples were obtained from eight nonexercising women (70 ± 2 years) before and after 12 weeks of training (20-45 minutes of cycle exercise per session at 60%-80% heart rate reserve, three to four sessions per week). Training elevated MHC I mRNA (p < .10) and protein (p < .05) in mixed-muscle (54% ± 4% to 61% ± 2%) and single myofibers (42% ± 4% to 52% ± 3%). The increase in MHC I protein was positively correlated (p < .05) with improvements in whole muscle power. Training resulted in a general downregulation of MHC IIa and IIx at the mRNA and protein levels. The training-induced increase in MHC I protein and mRNA demonstrates the maintenance of skeletal muscle plasticity with aging. Furthermore, these data suggest that a shift toward an oxidative MHC phenotype may be beneficial for metabolic and functional health in older individuals.
    Full-text · Article · Jun 2011 · The Journals of Gerontology Series A Biological Sciences and Medical Sciences
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    ABSTRACT: Millions of older individuals consume acetaminophen or ibuprofen daily and these same individuals are encouraged to participate in resistance training. Several in vitro studies suggest that cyclooxygenase-inhibiting drugs can alter tendon metabolism and may influence adaptations to resistance training. Thirty-six individuals were randomly assigned to a placebo (67 ± 2 yr old), acetaminophen (64 ± 1 yr old; 4,000 mg/day), or ibuprofen (64 ± 1 yr old; 1,200 mg/day) group in a double-blind manner and completed 12 wk of knee extensor resistance training. Before and after training in vivo patellar tendon properties were assessed with MRI [cross-sectional area (CSA) and signal intensity] and ultrasonography of patellar tendon deformation coupled with force measurements to obtain stiffness, modulus, stress, and strain. Mean patellar tendon CSA was unchanged (P > 0.05) with training in the placebo group, and this response was not influenced with ibuprofen consumption. Mean tendon CSA increased with training in the acetaminophen group (3%, P < 0.05), primarily due to increases in the mid (7%, P < 0.05) and distal (8%, P < 0.05) tendon regions. Correspondingly, tendon signal intensity increased with training in the acetaminophen group at the mid (13%, P < 0.05) and distal (15%, P = 0.07) regions. When normalized to pretraining force levels, patellar tendon deformation and strain decreased 11% (P < 0.05) and stiffness, modulus, and stress were unchanged (P > 0.05) with training in the placebo group. These responses were generally uninfluenced by ibuprofen consumption. In the acetaminophen group, tendon deformation and strain increased 20% (P < 0.05) and stiffness (-17%, P < 0.05) and modulus (-20%, P < 0.05) decreased with training. These data suggest that 3 mo of knee extensor resistance training in older adults induces modest changes in the mechanical properties of the patellar tendon. Over-the-counter doses of acetaminophen, but not ibuprofen, have a strong influence on tendon mechanical and material property adaptations to resistance training. These findings add to a growing body of evidence that acetaminophen has profound effects on peripheral tissues in humans.
    No preview · Article · May 2011 · Journal of Applied Physiology
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    ABSTRACT: Little is known about protein profiles in slow-twitch (MHC I) and fast-twitch (MHC IIa and MHC IIx) muscle fiber types from human skeletal muscle. PURPOSE: To develop a method of assessing fiber type specific protein content with low amounts of protein via Western blotting following single fiber SDS-PAGE MHC identification. METHODS: Two hundred and sixty four individual muscle fibers from a muscle biopsy of the vastus lateralis were isolated. Approximately ¼ of each single fiber was clipped and fiber-typed based on MHC composition using SDS-PAGE combined with silver staining. The remaining ¾ was stored in individually labeled wells of an RNALater filled 96-well plate. Following MHC identification, the preserved portions were combined into pools of 20 like fibers. Homogenized pools of known fiber types were loaded onto Western blots and probed for GAPDH, Actin, and total p38 to establish reliable protein detection using this methodology. RESULTS: At low amounts of protein, good reliability of this method was shown as MHC I and MHC IIa pools loaded in quintuplicate displayed 11% and 4% variance in GAPDH expression, respectively. When the amount of sample loaded on the blot doubled, GAPDH expression doubled in both MHC I and MHC IIa samples, implying consistent transferring and equal protein loading. Actin content did not differ between fiber types and was therefore found to be an appropriate loading control. GAPDH content was 67% (MHC IIa) and 84% (MHC IIx) more abundant when compared to MHC I pools. Similarly, total p38 expression was 40% greater in MHC IIa fibers when compared to MHC I fibers. CONCLUSION: These data establish a novel application of Western blotting for fiber type specific protein quantification in human skeletal muscle. These initial results show content of specific proteins are 40-84% higher in fast-twitch muscle fibers as compared to slow-twitch muscle fibers (MHC IIx>MHC IIa>MHC I). Application of these methods can enhance our knowledge on fiber type specific differences in relation to skeletal muscle health profiles among physically active and clinically based populations.
    Full-text · Conference Paper · May 2011

  • No preview · Article · May 2011 · Medicine & Science in Sports & Exercise

  • No preview · Article · May 2011 · Medicine & Science in Sports & Exercise

Publication Stats

4k Citations
450.94 Total Impact Points


  • 1996-2013
    • Ball State University
      • Human Performance Laboratory
      Muncie, Indiana, United States
    • University of Colorado Colorado Springs
      Colorado Springs, Colorado, United States
  • 2002-2004
    • University of Arkansas for Medical Sciences
      • Department of Physiology and Biophysics
      Little Rock, Arkansas, United States
    • Central Arkansas Veterans Healthcare System
      Washington, Washington, D.C., United States
  • 2001-2004
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States
  • 1997
    • University of Texas Medical Branch at Galveston
      Galveston, Texas, United States