| 1. |
- Cardinale, Daniele A., et al.
(författare)
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Resistance Training with Co-ingestion of Anti-inflammatory Drugs Attenuates Mitochondrial Function
- 2017
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Ingår i: Frontiers in Physiology. - : Frontiers Media SA. - 1664-042X. ; 8
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Tidskriftsartikel (refereegranskat)abstract
- Aim: The current study aimed to examine the effects of resistance exercise with concomitant consumption of high versus low daily doses of non-steroidal anti-inflammatory drugs (NSAIDs) on mitochondrial oxidative phosphorylation in skeletal muscle. As a secondary aim, we compared the effects of eccentric-overload with conventional training. Methods: Twenty participants were randomized to either a group taking high doses (3 x 400 mg/day) of ibuprofen (IBU; 27±5 yr; n=11) or a group ingesting a low dose (1 x 75 mg/day) of acetylsalicylic acid (ASA; 26±4 yr; n=9) during 8 weeks of supervised knee extensor resistance training. Each of the subject’s legs were randomized to complete the training program using either a flywheel (FW) device emphasizing eccentric-overload, or a traditional weight stack machine (WS). Maximal mitochondrial oxidative phosphorylation (CI+IIP) from permeabilized skeletal muscle bundles was assessed using high-resolution respirometry. Citrate synthase (CS) activity was assessed using spectrophotometric techniques and mitochondrial protein content using western blotting. Results: After training, CI+IIP decreased (P<0.05) in both IBU (23%) and ASA (29%) with no difference across medical treatments. Although CI+IIP decreased in both legs, the decrease was greater (interaction p = 0.015) in WS (33%, p = 0.001) compared with FW (19%, p = 0.078). CS activity increased (p = 0.027) with resistance training, with no interactions with medical treatment or training modality. Protein expression of ULK1 increased with training in both groups (p < 0.001). The increase in quadriceps muscle volume was not correlated with changes in CI+IIP (R=0.16). Conclusion: These results suggest that 8 weeks of resistance training with co-ingestion of anti-inflammatory drugs reduces mitochondrial function but increases mitochondrial content. The observed changes were not affected by higher doses of NSAIDs consumption, suggesting that the resistance training intervention was the prime mediator of the decreased mitochondrial phosphorylation. Finally, we noted that flywheel resistance training, emphasizing eccentric overload, rescued some of the reduction in mitochondrial function seen with conventional resistance training.
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| 2. |
- Cardinale, Daniele, et al.
(författare)
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Resistance Exercise Attenuates Mitochondrial Function : Effects Of NSAID Intake And Eccentric-Overload Training
- 2017
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Ingår i: Medicine & Science in Sports & Exercise. 49(5S):329, MAY 2017. - : Ovid Technologies (Wolters Kluwer Health). ; , s. 329-329
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Konferensbidrag (refereegranskat)abstract
- Although nonsteroidal antiinflammatorydrugs (NSAIDs) have been shown to modulate skeletal muscle adaptations and protein metabolism in response toresistance exercise, little is known about the effects of NSAIDs on mitochondrial function. Thus, the current study aimed to examine the effects of resistanceexercise with concomitant NSAID consumption on mitochondrial oxidative phosphorylation in skeletal muscle. Twenty participants were randomized in asingleblindedfashion to either an experimental group receiving ibuprofen (IBU: 27±5 yr; n=11; 1200 mg/d) or a control group receiving a lowdoseacetylsalicylic acid (CON: 26±4 yr; n=9; 75 mg/d) During this period, subjects performed 8 weeks of supervised resistance exercise involving the kneeextensors muscles. Each of the subject’s legs were randomized to complete the training program using either a flywheel (FW) device emphasizing eccentricoverload,or a traditional weight stack machine (WS). Maximal mitochondrial oxidative phosphorylation (OXPHOS) from permeabilized skeletal muscle bundleswas assessed using high resolution respirometry before and after the training intervention. Citrate synthase activity was assessed using spectrophotometrictechniques. After training, OXPHOS decreased (P<0.05) in both IBU (23%) and CON (29%) with no difference across medical treatments. Although OXPHOSdecreased in both legs, the decrease was greater (interaction P= 0.015) in WS (33%, P= 0.015) than in FW (19%, P= 0.078). Citrate synthase (CS) did notchange after the intervention. The increase in quadriceps muscle volume was not significantly correlated with the change in OXPHOS (R=0.15). These resultssuggest that 1) eight weeks of resistance training reduces mitochondrial function but not mitochondrial content, 2) The decreased mitochondrial function withresistance exercise was not affected by ibuprofen consumption, 3) flywheel resistance training, emphasizing eccentric overload, rescues some of thereduction in mitochondrial function seen with conventional resistance training.
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| 3. |
- Lilja, Mats, et al.
(författare)
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High-doses of anti-inflammatory drugs compromise muscle strength and hypertrophic adaptations to resistance training in young adults.
- 2018
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Ingår i: Acta Physiologica. - : Wiley. - 1748-1708 .- 1748-1716. ; 222:2
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Tidskriftsartikel (refereegranskat)abstract
- AIMS: This study tested the hypothesis that high doses of anti-inflammatory drugs would attenuate the adaptive response to resistance training compared with low doses.METHODS: Healthy men and women (aged 18-35 years) were randomly assigned to daily consumption of ibuprofen (IBU; 1200 mg; n=15) or acetylsalicylic acid (ASA; 75 mg; n=16) for 8 weeks. During this period, subjects completed supervised knee-extensor resistance training where one leg was subjected to training with maximal volitional effort in each repetition using a flywheel ergometer (FW), while the other leg performed conventional (work-matched across groups) weight-stack training (WS). Before and after training, muscle volume (MRI) and strength were assessed, and muscle biopsies were analysed for gene and protein expression of muscle growth regulators.RESULTS: The increase in m. quadriceps volume was similar between FW and WS, yet was (averaged across legs) greater in ASA (7.5%) compared with IBU (3.7%, group difference 34 cm(3) ; P=0.029). In the WS leg, muscle strength improved similarly (11-20%) across groups. In the FW leg, increases (10-23%) in muscle strength were evident in both groups yet they were generally greater (interaction effects P<0.05) for ASA compared with IBU. While our molecular analysis revealed several training effects, the only group interaction (P<0.0001) arose from a down-regulated mRNA expression of IL-6 in IBU.CONCLUSION: Maximal over-the-counter doses of ibuprofen attenuate strength and muscle hypertrophic adaptations to 8 weeks of resistance training in young adults. Thus, young individuals using resistance training to maximise muscle growth or strength should avoid excessive intake of anti-inflammatory drugs. This article is protected by copyright. All rights reserved.
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| 4. |
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| 5. |
- Mandić, Mirko, et al.
(författare)
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Automated assessment of regional muscle volume and hypertrophy using MRI
- 2020
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Ingår i: Scientific Reports. - : Nature Publishing Group. - 2045-2322. ; 10:1
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Tidskriftsartikel (refereegranskat)abstract
- This study aimed to validate a fully automatic method to quantify knee-extensor muscle volume and exercise-induced hypertrophy. By using a magnetic resonance imaging-based fat-water separated two-point Dixon sequence, the agreement between automated and manual segmentation of a specific ~15-cm region (partial volume) of the quadriceps muscle was assessed. We then explored the sensitivity of the automated technique to detect changes in both complete and partial quadriceps volume in response to 8 weeks of resistance training in 26 healthy men and women. There was a very strong correlation (r = 0.98, P < 0.0001) between the manual and automated method for assessing partial quadriceps volume, yet the volume was 9.6% greater with automated compared with manual analysis (P < 0.0001, 95% limits of agreement -93.3 ± 137.8 cm3). Partial muscle volume showed a 6.0 ± 5.0% (manual) and 4.8 ± 8.3% (automated) increase with training (P < 0.0001). Similarly, the complete quadriceps increased 5.1 ± 5.5% with training (P < 0.0001). The intramuscular fat proportion decreased (P < 0.001) from 4.1% to 3.9% after training. In conclusion, the automated method showed excellent correlation with manual segmentation and could detect clinically relevant magnitudes of exercise-induced muscle hypertrophy. This method could have broad application to accurately measure muscle mass in sports or to monitor clinical conditions associated with muscle wasting and fat infiltration.
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| 6. |
- Mandić, Mirko
(författare)
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Blood volume expansion following supramaximal exercise : occurrence and contribution to maximal oxygen uptake
- 2022
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Previously published research using various types of exercise has shown that central hemodynamic factors such as blood volume (BV) and maximal cardiac output (Qmax) are of large importance in the mediation of improvements in VO2max. Whether this is true for adaptations induced by sprint-interval training (SIT) is unclear. Three experimental studies were carried out investigating the occurrence and contribution of hypervolemia to SIT-induced improvements in VO2max. Forty-eight study participants performed the interventions. Significant increases in BV and Qmax were observed after the 6-week training interventions in conjunction with the expected increases in VO2max (Paper Ⅰ and Ⅱ). The hypervolemic response was shown not only to be associated with the increase in VO2max but also to be the primary mediator of it, as demonstrated by the elimination of the exercise-induced increases in VO2max when BV was normalized to pre-intervention levels by phlebotomy. This demonstrates that central adaptations are paramount for the SIT-induced increase in VO2max. In addition, systemic oxygen extraction increased as a consequence of decreased venous oxygen content during maximal exercise (Paper Ⅱ). This suggests that both peripheral and central factors are responsible for the adaptations in VO2max observed with SIT and refutes previous theories proposing that the increase in VO2max was mediated primarily by peripheral adaptations. Metabolic and intravascular perturbation has been proposed as an important stimuli for exercise adaptation. Since SIT is one of the most intense forms of exercise available the immediate effects after SIT are interesting in order to understand how such small amounts of exercise can lead to cardiovascular adaptations usually associated with more prolonged types of exercise. Acute effects of one session of SIT caused pronounced disturbance of the intravascular milieu and perturbations of the muscle metabolism. The variable that correlated best with changes in plasma and muscle volume was glucose-6-phosphate (Paper Ⅲ). Similarly, plasma osmolality and plasma concentration of arginine and citrulline was shown to be the best predictors of improvements in VO2max after a training intervention of 6-weeks (Paper Ⅳ). Overall, the present work demonstrates that brief supramaximal exercise leads to improvements in VO2max and that these improvements are mediated mainly by central adaptations. Peripheral adaptations occur concurrently but cannot alone explain the improvements in VO2max, as previously hypothesized. The data presented show that both central and peripheral adaptations are involved in the improvement of VO2max after an SIT intervention.
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| 7. |
- Mandic, Mirko, et al.
(författare)
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Interval-induced metabolic perturbation determines tissue fluid shifts into skeletal muscle
- 2021
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Ingår i: Physiological Reports. - : Wiley. - 2051-817X. ; 9:7
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Tidskriftsartikel (refereegranskat)abstract
- Intense interval exercise has proven to be as effective as traditional endurance exercise in improving maximal oxygen uptake. Shared by these two exercise regimes is an acute reduction in plasma volume, which is a suggested stimulus behind exercise-induced increases in blood volume and maximal oxygen uptake. This study aimed to link exercise-induced metabolic perturbation with volume shifts into skeletal muscle tissue. Ten healthy subjects (mean age 33 +/- 8 years, 5 males and 5 females) performed three 30 s all-out sprints on a cycle ergometer. Upon cessation of exercise magnetic resonance imaging, (31)Phosphorus magnetic resonance spectroscopy and blood samples were used to measure changes in muscle volume, intramuscular energy metabolites and plasma volume. Compared to pre-exercise, muscle volume increased from 1147.1 +/- 35.6 ml to 1283.3 +/- 11.0 ml 8 min post-exercise. At 30 min post-exercise, muscle volume was still higher than pre-exercise (1147.1 +/- 35.6 vs. 1222.2 +/- 6.8 ml). Plasma volume decreased by 16 +/- 3% immediately post-exercise and recovered back to - 5 +/- 6% after 30 min. Principal component analysis of exercise performance, muscle and plasma volume changes as well as changes in intramuscular energy metabolites showed generally strong correlations between metabolic and physiological variables. The strongest predictor for the volume shifts of muscle and plasma was the magnitude of glucose-6-phosphate accumulation post-exercise. Interval training leads to large metabolic and hemodynamic perturbations with accumulation of glucose-6-phosphate as a possible key event in the fluid flux between the vascular compartment and muscle tissue.
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| 8. |
- Wiik, Anna, et al.
(författare)
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Muscle Strength, Size, and Composition Following 12 Months of Gender-affirming Treatment in Transgender Individuals
- 2020
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Ingår i: Journal of Clinical Endocrinology and Metabolism. - : ENDOCRINE SOC. - 0021-972X .- 1945-7197. ; 105:3, s. E805-E813
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Tidskriftsartikel (refereegranskat)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.
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