Aerobic exercise does not compromise muscle hypertrophy response to short-term resistance training

2013 ◽  
Vol 114 (1) ◽  
pp. 81-89 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Rodrigo Fernandez-Gonzalo ◽  
Thomas Gustafsson ◽  
Per A. Tesch
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Muscle Size ◽  
Mrna Levels ◽  
Cross Sectional ◽  
Before And After

This study tested the hypothesis that chronic aerobic and resistance exercise (AE+RE) would elicit greater muscle hypertrophy than resistance exercise only (RE). Ten men (25 ± 4 yr) performed 5 wk unilateral knee extensor AE+RE. The opposing limb was subjected to RE. AE completed 6 hr prior to RE consisted of ∼45 min one-legged cycle ergometry. RE comprised 4 × 7 maximal concentric-eccentric knee extensions. Various indexes of in vivo knee extensor function were measured before and after training. Magnetic resonance imaging (MRI) assessed m. quadricep femoris (QF) cross-sectional area (CSA), volume, and signal intensity (SI). Biopsies obtained from m. vastus lateralis determined fiber CSA, enzyme levels, and gene expression of myostatin, atrogin-1, MuRF-1, PGC-1α, and VEGF. Increases ( P < 0.05) in isometric strength and peak power, respectively, were comparable in AE+RE (9 and 29%) and RE (11 and 24%). AE+RE showed greater increase (14%; P < 0.05) in QF volume than RE (8%). Muscle fiber CSA increased 17% after AE+RE ( P < 0.05) and 9% after RE ( P > 0.05). QF SI increased (12%; P < 0.05) after AE+RE, but not RE. Neither AE+RE nor RE showed altered mRNA levels. Citrate synthase activity increased ( P < 0.05) after AE+RE. The results suggest that the increased aerobic capacity shown with AE+RE was accompanied by a more robust increase in muscle size compared with RE. Although this response was not carried over to greater improvement in muscle function, it remains that intense AE can be executed prior to RE without compromising performance outcome.

scholarly journals Regional and muscle-specific adaptations in knee extensor hypertrophy using flywheel versus conventional weight-stack resistance exercise

2019 ◽  
Vol 44 (8) ◽  
pp. 827-833 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Maria T. García-Gutiérrez ◽  
Mirko Mandić ◽  
Mats Lilja ◽  
Rodrigo Fernandez-Gonzalo
Keyword(s):  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Rectus Femoris ◽  
Knee Extension ◽  
Knee Extensors ◽  
Cross Sectional ◽  
Proximal Site ◽  
Before And After

This study compared the effects of the most frequently employed protocols of flywheel (FW) versus weight-stack (WS) resistance exercise (RE) on regional and muscle-specific adaptations of the knee extensors. Sixteen men (n = 8) and women (n = 8) performed 8 weeks (2–3 days/week) of knee extension RE employing FW technology on 1 leg (4 × 7 repetitions), while the contralateral leg performed regular WS training (4 × 8–12 repetitions). Maximal strength (1-repetition maximum (1RM) in WS) and peak FW power were determined before and after training for both legs. Partial muscle volume of vastus lateralis (VL), vastus medialis (VM), vastus intermedius (VI), and rectus femoris (RF) were measured using magnetic resonance imaging. Additionally, quadriceps cross-sectional area was assessed at a proximal and a distal site. There were no differences (P > 0.05) between FW versus WS in muscle hypertrophy of the quadriceps femoris (8% vs. 9%), VL (10% vs. 11%), VM (6% vs. 8%), VI (5% vs. 5%), or RF (17% vs. 17%). Muscle hypertrophy tended (P = 0.09) to be greater at the distal compared with the proximal site, but there was no interaction with exercise method. Increases in 1RM and FW peak power were similar across legs, yet the increase in 1RM was greater in men (31%) than in women (20%). These findings suggest that FW and WS training induces comparable muscle-specific hypertrophy of the knee extensors. Given that these robust muscular adaptations were brought about with markedly fewer repetitions in the FW compared with WS, it seems FW training can be recommended as a particularly time-efficient exercise paradigm.

scholarly journals Changes in muscle size and MHC composition in response to resistance exercise with heavy and light loading intensity

2008 ◽  
Vol 105 (5) ◽  
pp. 1454-1461 ◽  
Author(s):  
L. Holm ◽  
S. Reitelseder ◽  
T. G. Pedersen ◽  
S. Doessing ◽  
S. G. Petersen ◽  
...  
Keyword(s):  
Resistance Training ◽  
Muscle Strength ◽  
Resistance Exercise ◽  
Muscle Hypertrophy ◽  
Vastus Lateralis ◽  
Load Resistance ◽  
Muscle Size ◽  
Heavy Load ◽  
Cross Sectional ◽  
Light Load

Muscle mass accretion is accomplished by heavy-load resistance training. The effect of light-load resistance exercise has been far more sparsely investigated with regard to potential effect on muscle size and contractile strength. We applied a resistance exercise protocol in which the same individual trained one leg at 70% of one-repetition maximum (1RM) (heavy load, HL) while training the other leg at 15.5% 1RM (light load, LL). Eleven sedentary men (age 25 ± 1 yr) trained for 12 wk at three times/week. Before and after the intervention muscle hypertrophy was determined by magnetic resonance imaging, muscle biopsies were obtained bilaterally from vastus lateralis for determination of myosin heavy chain (MHC) composition, and maximal muscle strength was assessed by 1RM testing and in an isokinetic dynamometer at 60°/s. Quadriceps muscle cross-sectional area increased ( P < 0.05) 8 ± 1% and 3 ± 1% in HL and LL legs, respectively, with a greater gain in HL than LL ( P < 0.05). Likewise, 1RM strength increased ( P < 0.001) in both legs (HL: 36 ± 5%, LL: 19 ± 2%), albeit more so with HL ( P < 0.01). Isokinetic 60°/s muscle strength improved by 13 ± 5% ( P < 0.05) in HL but remained unchanged in LL (4 ± 5%, not significant). Finally, MHC IIX protein expression was decreased with HL but not LL, despite identical total workload in HL and LL. Our main finding was that LL resistance training was sufficient to induce a small but significant muscle hypertrophy in healthy young men. However, LL resistance training was inferior to HL training in evoking adaptive changes in muscle size and contractile strength and was insufficient to induce changes in MHC composition.

scholarly journals Specific force of the vastus lateralis in adults with achondroplasia

2018 ◽  
Vol 124 (3) ◽  
pp. 696-703 ◽  
Author(s):  
David T. Sims ◽  
Gladys L. Onambélé-Pearson ◽  
Adrian Burden ◽  
Carl Payton ◽  
Christopher I. Morse
Keyword(s):  
Vastus Lateralis ◽  
Force Production ◽  
Limb Length ◽  
Muscle Size ◽  
Knee Extensors ◽  
Specific Force ◽  
Moment Arm ◽  
Cross Sectional ◽  
Volume Activation

Achondroplasia is a clinical condition defined by shorter stature and disproportionate limb length. Force production in able-bodied individuals (controls) is proportional to muscle size, but given the disproportionate nature of achondroplasia, normalizing to anatomical cross-sectional area (ACSA) is inappropriate. The aim of this study was to assess specific force of the vastus lateralis (VL) in 10 adults with achondroplasia (22 ± 3 yr) and 18 sex-matched controls (22 ± 2 yr). Isometric torque (iMVCτ) of the dominant knee extensors (KE) and in vivo measures of VL muscle architecture, volume, activation, and patella tendon moment arm were used to calculate VL physiological CSA (PCSA), fascicle force, and specific force in both groups. Achondroplasic muscle volume was 53% smaller than controls (284 ± 36 vs. 604 ± 102 cm3, P < 0.001). KE iMVCτ was 63% lower in achondroplasia compared with controls (95 ± 24 vs. 256 ± 47 N⋅m, P < 0.001). Activation and moment arm length were similar between groups ( P > 0.05), but coactivation of bicep femoris of achondroplasic subjects was 70% more than controls (43 ± 20 vs. 13 ± 5%, P < 0.001). Achondroplasic subjects had 58% less PCSA (43 ± 10 vs. 74.7 ± 14 cm2, P < 0.001), 29% lower fascicle force (702 ± 235 vs. 1704 ± 303 N, P < 0.001), and 29% lower specific force than control subjects (17 ± 6 vs. 24 ± 6 N⋅cm−2, P = 0.012). The smaller VL specific force in achondroplasia may be attributed to infiltration of fat and connective tissue, rather than to any difference in myofilament function. NEW & NOTEWORTHY The novel observation of this study was the measurement of normalized force production in a group of individuals with disproportionate limb length-to-torso ratios.

Training can improve muscle strength and endurance in 78- to 84-yr-old men

1992 ◽  
Vol 73 (6) ◽  
pp. 2517-2523 ◽  
Author(s):  
G. Grimby ◽  
A. Aniansson ◽  
M. Hedberg ◽  
G. B. Henning ◽  
U. Grangard ◽  
...  
Keyword(s):  
Muscle Strength ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Knee Extension ◽  
Emg Activity ◽  
Vastus Lateralis Muscle ◽  
Neural Activation ◽  
Cross Sectional ◽  
Before And After ◽  
The Right

Nine men, 78–84 yr of age, participated in a dynamometer training program 2–3 times/wk, totaling 25 sessions, using voluntary maximal isometric, concentric, and eccentric right knee–extension actions (30 and 180 degrees/s). Measurements of muscle strength with a Kin-Com dynamometer and simultaneous electromyograms (EMG) were performed of both sides before and after the training period. Muscle biopsies were taken from the right vastus lateralis muscle. The total quadriceps cross-sectional area was measured with computerized tomography. Training led to an increase in maximal torque for concentric (10% at 30 degrees/s) and eccentric (13–19%) actions in the trained leg. The EMG activity increased at maximal eccentric activities. The total cross-sectional quadriceps area of the trained leg increased by 3%, but no changes were recorded in muscle fiber areas in these subjects, who already had large mean fiber areas (5.15 microns 2 x 10(3)). The fatigue index measured from 50 consecutive concentric contractions at 180 degrees/s decreased and the citrate synthase activity increased in all but one subject. The results demonstrate that increased neural activation accompanies an increase in muscle strength at least during eccentric action in already rather active elderly men and that muscle endurance may also be improved with training.

scholarly journals Exercise-induced AMPK activation does not interfere with muscle hypertrophy in response to resistance training in men

2014 ◽  
Vol 116 (6) ◽  
pp. 611-620 ◽  
Author(s):  
Tommy R. Lundberg ◽  
Rodrigo Fernandez-Gonzalo ◽  
Per A. Tesch
Keyword(s):  
Gene Expression ◽  
Glycogen Content ◽  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Endurance Performance ◽  
Quadriceps Muscle ◽  
Muscle Size ◽  
Vastus Lateralis Muscle ◽  
Myostatin Gene

As aerobic exercise (AE) may interfere with adaptations to resistance exercise (RE), this study explored acute and chronic responses to consecutive AE (∼45 min cycling) and RE (4 × 7 maximal knee extensions) vs. RE only. Ten men performed acute unilateral AE + RE interspersed by 15 min recovery. The contralateral leg was subjected to RE. This exercise paradigm was then implemented in a 5-wk training program. Protein phosphorylation, gene expression, and glycogen content were assessed in biopsies obtained from the vastus lateralis muscle of both legs immediately before and 3 h after acute RE. Quadriceps muscle size and in vivo torque were measured, and muscle samples were analyzed for citrate synthase activity and glycogen concentration, before and after training. Acute AE reduced glycogen content (32%; P < 0.05) and increased ( P < 0.05) phosphorylation of AMPK (1.5-fold) and rpS6 (1.3-fold). Phosphorylation of p70S6K and 4E-BP1 remained unchanged. Myostatin gene expression was downregulated after acute AE + RE but not RE. Muscle size showed greater ( P < 0.05) increase after AE + RE (6%) than RE (3%) training. Citrate synthase activity (18%) and endurance performance (22%) increased ( P < 0.05) after AE + RE but not RE. While training increased ( P < 0.05) in vivo muscle strength in both legs, normalized and concentric torque increased after RE only. Thus AE activates AMPK, reduces glycogen stores, and impairs the progression of concentric force, yet muscle hypertrophic responses to chronic RE training appear not to be compromised.

Interaction between concurrent strength and endurance training

1990 ◽  
Vol 68 (1) ◽  
pp. 260-270 ◽  
Author(s):  
D. G. Sale ◽  
J. D. MacDougall ◽  
I. Jacobs ◽  
S. Garner
Keyword(s):  
Citrate Synthase ◽  
Vastus Lateralis ◽  
Knee Extensor ◽  
Knee Extension ◽  
Cycle Ergometer ◽  
The Other ◽  
Leg Press ◽  
Group 4 ◽  
Before And After ◽  
Slow Twitch Fibers

To assess the effects of concurrent strength (S) and endurance (E) training on S and E development, one group (4 young men and 4 young women) trained one leg for S and the other leg for S and E (S+E). A second group (4 men, 4 women) trained one leg for E and the other leg for E and S (E+S). E training consisted of five 3-min bouts on a cycle ergometer at a power output corresponding to that requiring 90-100% of oxygen uptake during maximal exercise (VO2 max). S training consisted of six sets of 15-20 repetitions with the heaviest possible weight on a leg press (combined hip and knee extension) weight machine. Training was done 3 days/wk for 22 wk. Needle biopsy samples from vastus lateralis were taken before and after training and were examined for histochemical, biochemical, and ultrastructural adaptations. The nominal S and E training programs were “hybrids”, having more similarities as training stimuli than differences; thus S made increases (P less than 0.05) similar to those of S+E in E-related measures of VO2max (S, S+E: 8%, 8%), repetitions with the pretraining maximal single leg press lift [1 repetition maximum (RM)] (27%, 24%), and percent of slow-twitch fibers (15%, 8%); and S made significant, although smaller, increases in repetitions with 80% 1 RM (81%, 152%) and citrate synthase (CS) activity (22%, 51%). Similarly, E increased knee extensor area [computed tomography (CT) scans] as much as E+S (14%, 21%) and made significant, although smaller, increases in leg press 1 RM (20%, 34%) and thigh girth (3.4%, 4.8%). When a presumably stronger stimulus for an adaptation was added to a weaker one, some additive effects occurred (i.e., increases in 1 RM and thigh girth that were greater in E+S than E; increases in CS activity and repetitions with 80% 1 RM that were greater in S+E than S). When a weaker, although effective, stimulus was added to a stronger one, addition generally did not occur. Concurrent S and E training did not interfere with S or E development in comparison to S or E training alone.

Muscle Strength, Size, and Composition Following 12 Months of Gender-affirming Treatment in Transgender Individuals

2019 ◽  
Vol 105 (3) ◽  
pp. e805-e813 ◽  
Author(s):  
Anna Wiik ◽  
Tommy R Lundberg ◽  
Eric Rullman ◽  
Daniel P Andersson ◽  
Mats Holmberg ◽  
...  
Keyword(s):  
Muscle Mass ◽  
Muscle Function ◽  
Treatment Initiation ◽  
Hormone Replacement ◽  
Knee Extensor ◽  
Muscle Volume ◽  
Muscle Size ◽  
Thigh Muscle ◽  
Cross Sectional ◽  
One Year

Abstract Context As many sports are divided in male/female categories, governing bodies have formed regulations on the eligibility for transgender individuals to compete in these categories. Yet, the magnitude of change in muscle mass and strength with gender-affirming treatment remains insufficiently explored. Objective This study explored the effects of gender-affirming treatment on muscle function, size, and composition during 12 months of therapy. Design, settings, participants In this single-center observational cohort study, untrained transgender women (TW, n = 11) and transgender men (TM, n = 12), approved to start gender-affirming medical interventions, underwent assessments at baseline, 4 weeks after gonadal suppression of endogenous hormones but before hormone replacement, and 4 and 12 months after treatment initiation. Main outcome measures Knee extensor and flexor strength were assessed at all examination time points, and muscle size and radiological density (using magnetic resonance imaging and computed tomography) at baseline and 12 months after treatment initiation. Results Thigh muscle volume increased (15%) in TM, which was paralleled by increased quadriceps cross-sectional area (CSA) (15%) and radiological density (6%). In TW, the corresponding parameters decreased by –5% (muscle volume) and –4% (CSA), while density remained unaltered. The TM increased strength over the assessment period, while the TW generally maintained their strength levels. Conclusions One year of gender-affirming treatment resulted in robust increases in muscle mass and strength in TM, but modest changes in TW. These findings add new knowledge on the magnitude of changes in muscle function, size, and composition with cross-hormone therapy, which could be relevant when evaluating the transgender eligibility rules for athletic competitions.

scholarly journals Omega-3 supplementation improves isometric strength but not muscle anabolic and catabolic signaling in response to resistance exercise in healthy older adults

2020 ◽  
Author(s):  
Sebastiaan Dalle ◽  
Evelien Van Roie ◽  
Charlotte Hiroux ◽  
Mathias Vanmunster ◽  
Walter Coudyzer ◽  
...  
Keyword(s):  
Older Adults ◽  
Resistance Exercise ◽  
Corn Oil ◽  
Knee Extensor ◽  
Muscle Volume ◽  
Isometric Strength ◽  
Muscle Quality ◽  
Omega 3 ◽  
Muscle Inflammation ◽  
Before And After

Abstract Old skeletal muscle exhibits decreased anabolic sensitivity, eventually contributing to muscle wasting. Besides anabolism, also muscle inflammation and catabolism are critical players in regulating the old skeletal muscle’s sensitivity. Omega-3 fatty acids (ω-3) are an interesting candidate to reverse anabolic insensitivity via anabolic actions. Yet, it remains unknown whether ω-3 also attenuates muscle inflammation and catabolism. The present study investigates the effect of ω-3 supplementation on muscle inflammation and metabolism (anabolism/catabolism) upon resistance exercise (RE). Twenty-three older adults (OA) (65-84yr;8♀) were randomized to receive ω-3 (~3g·d -1) or corn oil (PLAC) and engaged in a 12-wk RE program (3x·wk -1). Before and after intervention, muscle volume, strength and systemic inflammation were assessed, and muscle biopsies were analysed for markers of anabolism, catabolism and inflammation. Isometric knee-extensor strength increased in ω-3 (+12.2%), but not in PLAC (-1.4%; pinteraction=0.015), whereas leg press strength improved in both conditions (+27.1%; ptime&lt;0.001). RE, but not ω-3, decreased inflammatory (p65NF-κB) and catabolic (FOXO1, LC3b) markers, and improved muscle quality. Yet, muscle volume remained unaffected by RE and ω-3. Accordingly, muscle anabolism (mTORC1) and plasma CRP remained unchanged by RE and ω-3, whereas serum IL-6 tended to decrease in ω-3 (pinteraction=0.07). These results show that, despite no changes in muscle volume, RE-induced gains in isometric strength can be further enhanced by ω-3. However, ω-3 did not improve RE-induced beneficial catabolic or inflammatory adaptations. Irrespective of muscle volume, gains in strength (primary criterion for sarcopenia) might be explained by changes in muscle quality due to muscle inflammatory or catabolic signaling.

scholarly journals In vivo strain of the medial vs. lateral quadriceps tendon in patellofemoral pain syndrome

2009 ◽  
Vol 107 (2) ◽  
pp. 422-428 ◽  
Author(s):  
Nicole A. Wilson ◽  
Joel M. Press ◽  
Li-Qun Zhang
Keyword(s):  
Vastus Lateralis ◽  
Knee Extensor ◽  
Pain Syndrome ◽  
Quadriceps Tendon ◽  
Biomechanical Properties ◽  
Patellofemoral Pain ◽  
Control Subjects ◽  
Patellar Maltracking ◽  
Tendon Strain

Patellofemoral pain (PFP) is thought to be related to patellar maltracking due to imbalances in the knee extensor. However, no study has evaluated the in vivo biomechanical properties of the quadriceps tendon in PFP syndrome. Our purpose was to compare the biomechanical properties of the quadriceps tendons in vivo and noninvasively in patients with PFP syndrome to those of control subjects. The null hypothesis was that the quadriceps tendons of PFP subjects would have significantly decreased strain compared with control subjects. Fourteen subjects (7 control, 7 PFP) performed voluntary ramp isometric contractions to a range of torque levels, while quadriceps tendon elongation was measured using ultrasonography. Tendon strain was calculated for the vastus medialis obliquus (VMO) and vastus lateralis (VL) portion of the quadriceps tendon and compared between subjects (control vs. PFP) and within subjects (VMO vs. VL). PFP subjects showed significantly less VMO tendon strain than control subjects ( P < 0.001), but there was no difference in VL tendon strain between PFP and control subjects ( P = 0.100). Relative weakness of the VMO is the most likely cause of the decreased tendon strain seen in subjects with PFP. VMO weakness not only explains the decreased medial tendon strain but also explains the presence of increased lateral patellar translation and lateral patellar spin (distal pole rotates laterally) reported in the literature in this population. This technique can potentially be used in a clinical setting to evaluate quadriceps tendon properties and infer the presence of muscle weakness in PFP.

Effect of Honey and Green Tea Solutions on Streptococcus mutans

2015 ◽  
Vol 39 (5) ◽  
pp. 435-441
Author(s):  
F Abdelmegid ◽  
M Al-Agamy ◽  
A Alwohaibi ◽  
H Ka'abi ◽  
F Salama
Keyword(s):  
Streptococcus Mutans ◽  
Green Tea ◽  
Saliva Sample ◽  
Post Intervention ◽  
Cross Sectional ◽  
Colony Forming Unit ◽  
Before And After ◽  
The Mean ◽  
Mouth Rinsing

Objectives: The aim of this cross-sectional in vivo study was to assess the effect of green tea and honey solutions on the level of salivary Streptococcus mutans. Study design: A convenient sample of 30 Saudi boys aged 7–10 years were randomly assigned into 2 groups of 15 each. Saliva sample was collected for analysis of level of S. mutans before rinsing. Commercial honey and green tea were prepared for use and each child was asked to rinse for two minutes using 10 mL of the prepared honey or green tea solutions according to their group. Saliva samples were collected again after rinsing. The collected saliva samples were prepared and colony forming unit (CFU) of S. mutans per mL of saliva was calculated. Results: The mean number of S. mutans before and after rinsing with honey and green tea solutions were 2.28* 108(2.622*108), 5.64 *107(1.03*108), 1.17*109(2.012*109) and 2.59*108 (3.668*108) respectively. A statistically significant reduction in the average number of S. mutans at baseline and post intervention in the children who were assigned to the honey (P=0.001) and green tea (P=0.001) groups was found. Conclusions: A single time mouth rinsing with honey and green tea solutions for two minutes effectively reduced the number of salivary S. mutans of 7–10 years old boys.

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