Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

The main goal of the current study was to compare the effects of volume-equated training frequency on gains in muscle mass and strength. In addition, we aimed to investigate whether the effect of training frequency was affected by the complexity, concerning the degrees of freedom, of an exercise. Participants were randomized to a moderate training frequency group (two weekly sessions) or high training frequency group (four weekly sessions). Twenty-one participants (male: 11, female: 10, age: 25.9 ± 4.0) completed the 9-week whole-body progressive heavy resistance training intervention with moderate (n = 13) or high (n = 8) training frequency. Whole-body and regional changes in lean mass were measured using dual-energy x-ray absorptiometry, while the vastus lateralis thickness was measured by ultrasound. Changes in muscle strength were measured as one repetition maximum for squat, hack squat, bench press, and chest press. No differences between groups were observed for any of the measures of muscle growth or muscle strength. Muscle strength increased to a greater extent in hack squat and chest press than squat and bench press for both moderate (50 and 21% vs. 19 and 14%, respectively) and high-frequency groups (63 and 31% vs. 19 and 16%, respectively), with no differences between groups. These results suggest that training frequency is less decisive when weekly training volume is equated. Further, familiarity with an exercise seems to be of greater importance for strength adaptations than the complexity of the exercise.publishedVersio

Vitamin D3 supplementation does not enhance the effects of resistance training in older adults

Background: Lifestyle therapy with resistance training is a potent measure to counteract age-related loss in muscle strength and mass. Unfortunately, many individuals fail to respond in the expected manner. This phenomenon is particularly common among older adults and those with chronic diseases (e.g. chronic obstructive pulmonary disease, COPD) and may involve endocrine variables such as vitamin D. At present, the effects of vitamin D supplementation on responses to resistance training remain largely unexplored. Methods: Ninety-five male and female participants (healthy, n = 71; COPD, n = 24; age 68 ± 5 years) were randomly assigned to receive either vitamin D3 or placebo supplementation for 28 weeks in a double-blinded manner (latitude 61°N, September-May). Seventy-eight participants completed the RCT, which was initiated by 12 weeks of supplementation-only (two weeks with 10 000 IU/day, followed by 2000 IU/day), followed by 13 weeks of combined supplementation (2000 IU/day) and supervised whole-body resistance training (twice weekly), interspersed with testing and measurements. Outcome measures included multiple assessments of muscle strength (nvariables = 7), endurance performance (n = 6), and muscle mass (n = 3, legs, primary), as well as muscle quality (legs), muscle biology (m. vastus lateralis; muscle fibre characteristics, transcriptome), and health-related variables (e.g. visceral fat mass and blood lipid profile). For main outcome domains such as muscle strength and muscle mass, weighted combined factors were calculated from the range of singular assessments. Results: Overall, 13 weeks of resistance training increased muscle strength (13% ± 8%), muscle mass (9% ± 8%), and endurance performance (one-legged, 23% ± 15%; whole-body, 8% ± 7%), assessed as weighted combined factors, and were associated with changes in health variables (e.g. visceral fat, -6% ± 21%; [LDL]serum , -4% ± 14%) and muscle tissue characteristics such as fibre type proportions (e.g. IIX, -3% points), myonuclei per fibre (30% ± 65%), total RNA/rRNA abundances (15%/6-19%), and transcriptome profiles (e.g. 312 differentially expressed genes). Vitamin D3 supplementation did not affect training-associated changes for any of the main outcome domains, despite robust increases in [25(OH)D]serum (∆49% vs. placebo). No conditional effects were observed for COPD vs. healthy or pre-RCT [25(OH)D]serum . In secondary analyses, vitamin D3 affected expression of gene sets involved in vascular functions in muscle tissue and strength gains in participants with high fat mass, which advocates further study. Conclusions: Vitamin D3 supplementation did not affect muscular responses to resistance training in older adults with or without COPD. Keywords: Cholecalciferol; Muscle plasticity; Strength training. © 2021 The Authors. Journal of Cachexia, Sarcopenia and Muscle published by John Wiley & Sons Ltd on behalf of Society on Sarcopenia, Cachexia and Wasting Disorders.publishedVersio

Effekten av restitusjonsdrikken Smartfish og vitamin C og E på hypertrofisignalering etter en styrketreningsøkt

Innledning: Inntak av kosttilskudd med proteiner og antioksidanter kan påvirke den akutte aktiveringen av signaleringsproteiner i muskelcellene og restitusjon etter en styrketreningsøkt. Gjennom disse mekanismene kan slike tilskudd derfor også påvirke de langsiktige adaptasjonene til styrketrening. Stort inntak av antioksidanter kan imidlertid også teoretisk hindre adaptasjon til styrketrening gjennom å ved redusere virkningen av frie radikaler, som synes å være viktige i aktiveringen av signaleringsproteiner i muskelceller som respons på treningsstimuli.. Hensikten med denne studien var derfor å teste ut effekten av et antioksidanttilskudd (vitamin C + E) og et tilskudd som inneholdt protein, omega-3 og beta-alanin (Smarfish) på den akutte effekten av en styrketreningsøkt og på den langvarige effekten av en periode med styrketrening. Metode: I denne delen av studien ble 15 godt trente kvinner (6) og menn (9) rekrutterte fra den større SARA-studien ved NIH. Det var fem forsøkspersoner fra hver av de tre gruppene i studien: Smartfish, Vitamin C+ E og Placebo. Forsøkspersonene gjennomførte en intensiv styrketreningsøkt for knestrekkerne. Det ble tatt to biopsier før og 100 og 150 minutter etter økten. Prestasjonstester ble gjennomført før, rett etter, 160 minutter og 24 timer etter økten. Muskelbiopsiene ble analysert for aktivering (fosforylering/defosforylering) av signaleringsproteinene p70S6K, RPS6 og eEF-2 (westernblot). I tillegg ble effekten av 10 uker med styrketrening målt som endring i styrke i knestrekkerne og som endring i fettfri masse i beina. Resultater: Styrkeøkten medførte økt fosforylering av p70S6K for alle forsøkspersonene samlet. Det var ingen gruppeforskjeller i aktiveringen av p70S6K og RPS6 eller i restitusjonstiden. For eEF-2 tenderte vitamingruppen mot en økt aktivering (defosforylering), mens det ikke var noen endringer i de andre gruppene. Det var en tendens til at økningen i fettfri masse i beina var større i Smartfish og Vitamin C+E gruppene enn i placebogruppen, men det var ingen forskjell mellom gruppene i økningen i styrke. Diskusjon: Proteinsupplementering er tidligere vist å øke hypertrofisignalering og påskynde restitusjonsprosessen. Smartfish ga imidlerid ingen målbar effekt utover placebo i dette restitusjonsforøket. Dette kan skyldes for lav proteinmengde i Smartfishdrikken (7 g). Vitaminenes effekt på eEF-2 var uventet, da det er i strid med hypotesen om redusert signalering, men samtidig var det også en tendens til mindre aktivering av p70S6K som e ri tråd med hypotesen. Konklusjon: Styrketreningsøkten medførte økt aktivering av p70S6K, men det var ingen forskjell mellom gruppene. Smartfish fremmet derfor ikke signalering eller restitusjonsprosessen. Trass i få deltagere og relativt stor individuell variasjon finner vi en tendens til effekt av vitamin C+E på eEF-2. Dette tyder på en positiv effekt av disse vitaminene og bør undersøkes videre. Effekten på treningstilpasninger over tid er usikker basert på disse resultatene, da det var en tendens til større muskelvekst i Smartfish gruppen og i Vitamin C+E gruppen, men ingen forskjell mellom gruppene i økning i muskelstyrke. Flere forsøkspersoner må inkluderes i disse analysene før vi kan trekke noen sikrere konklusjoner

Can supplementation with vitamin C and E alter physiological adaptations to strength training?

Background: Antioxidant supplementation has recently been demonstrated to be a double-edged sword, because small to moderate doses of exogenous antioxidants are essential or beneficial, while high doses may have adverse effects. The adverse effects can be manifested in attenuated effects of exercise and training, as the antioxidants may shut down some redox-sensitive signaling in the exercised muscle fibers. However, conditions such as age may potentially modulate the need for antioxidant intake. Therefore, this paper describes experiments for testing the hypothesis that high dosages of vitamin C (1000 mg/day) and E (235 mg/day) have negative effects on adaptation to resistance exercise and training in young volunteers, but positive effects in older men. Methods/design: We recruited a total of 73 volunteers. The participants were randomly assigned to receiving either vitamin C and E supplementation or a placebo. The study design was double-blinded, and the participants followed an intensive training program for 10–12 weeks. Tests and measurements aimed at assessing changes in physical performance (maximal strength) and physiological characteristics (muscle mass), as well as biochemical and cellular systems and structures (e.g., cell signaling and morphology). Discussion: Dietary supplements, such as vitamin C and E, are used by many people, especially athletes. The users often believe that high dosages of supplements improve health (resistance to illness and disease) and physical performance. These assumptions are, however, generally not supported in the scientific literature. On the contrary, some studies have indicated that high dosages of antioxidant supplements have negative effects on exercise-induced adaptation processes. Since this issue concerns many people and few randomized controlled trials have been conducted in humans, further studies are highly warranted

Equal-Volume Strength Training With Different Training Frequencies Induces Similar Muscle Hypertrophy and Strength Improvement in Trained Participants

The main goal of the current study was to compare the effects of volume-equated training frequency on gains in muscle mass and strength. In addition, we aimed to investigate whether the effect of training frequency was affected by the complexity, concerning the degrees of freedom, of an exercise. Participants were randomized to a moderate training frequency group (two weekly sessions) or high training frequency group (four weekly sessions). Twenty-one participants (male: 11, female: 10, age: 25.9 ± 4.0) completed the 9-week whole-body progressive heavy resistance training intervention with moderate (n = 13) or high (n = 8) training frequency. Whole-body and regional changes in lean mass were measured using dual-energy x-ray absorptiometry, while the vastus lateralis thickness was measured by ultrasound. Changes in muscle strength were measured as one repetition maximum for squat, hack squat, bench press, and chest press. No differences between groups were observed for any of the measures of muscle growth or muscle strength. Muscle strength increased to a greater extent in hack squat and chest press than squat and bench press for both moderate (50 and 21% vs. 19 and 14%, respectively) and high-frequency groups (63 and 31% vs. 19 and 16%, respectively), with no differences between groups. These results suggest that training frequency is less decisive when weekly training volume is equated. Further, familiarity with an exercise seems to be of greater importance for strength adaptations than the complexity of the exercise

No Difference Between Spray Dried Milk and Native Whey Supplementation with Strength Training

Background: A rapid digestibility and high leucine content are considered important for maximal stimulation of muscle protein synthesis. Consequently, with these properties, native whey may hold greater anabolic potential than milk, when supplemented in combination with strength training. Our aim was to compare the effects of supplementation with milk or native whey, during a 12-week strength training period, on gains in muscle mass and strength in young adults. Methods: In this double-blinded, randomized, controlled study a total of 40 untrained young men and women received two daily servings of either milk or native whey containing 20 g of protein, during a 12-week strength training intervention. Muscle strength, lean mass, thigh muscle cross sectional area, m. vastus lateralis thickness and muscle fiber cross sectional area were assessed before and after the training period. In addition, the acute phosphorylation of the anabolic kinases p70S6K, 4E-BP1 and eEF-2 in response to a standardized workout and supplementation was investigated before and after the 12-week training period. Results: Muscle mass and strength increased, by all measures applied (5-16%, P 0.25). p70S6K phosphorylation increased (~1000%, P 0.40). No correlation between these acute measures and changes in muscle mass or strength were observed. Conclusion: Supplementation with milk or native whey during a 12-week strength training period did not differentially affect muscle mass and strength in young untrained individuals

Depressed Physical Performance Outlasts Hormonal Disturbances after Military Training

. Introduction: The aim of this study was to investigate the effect of an arduous 1-wk military course on measures of physical performance, body composition, and blood biomarkers. Methods: Participants were apprentices in an annual selection course for the Norwegian Special Forces. Fifteen soldiers (23 T 4 yr, 1.81 T 0.06 m, 78 T 7 kg) completed a hell week consisting of rigorous activity only interspersed by 2 to 3 h of sleep per day. Testing was conducted before and 0, 1, 3, 7, and 14 d after the hell week. Physical performance was measured as muscle strength and jump performance. Body composition was measured by bioelectrical impedance and blood samples were collected and analyzed for hormones, creatine kinase, and C-reactive protein. Results: Body mass was reduced by 5.3 T 1.9 kg during the hell week and returned to baseline within 1 wk. Fat mass was reduced by 2.1 T 1.7 kg and muscle mass by 1.9 T 0.9 kg. Muscle strength in leg press and bench press was reduced by 20% T 9% and 9% T 7%, respectively, and both were approximately 10% lower than baseline after 1 wk of recovery. Jump-height was reduced by 28% T 13% and was still 14% T 5% below baseline after 2 wk of recovery. Testosterone was reduced by 70% T 12% and recovered gradually within a week. Cortisol was increased by 154% T 74% and did not fully recover during the next week. Insulin-like growth factor 1 was reduced by 51% T 10% and triiodothyronine and thyroxine by 12% to 30%, all recovered within a week. Conclusions: One-week arduous military exercise resulted in reductions in body mass and performance, as well as considerable hormonal disturbances. Our most important observation was that whereas the hormonal systems was normalized within 1 wk of rest and proper nutrition, lower body strength and jump performance were still depressed after 2 wk

Participación de las MIPYMES en las contrataciones menores reguladas por la Ley 737, Ley de contrataciones administrativas del sector público y su reglamento

Plantea que a pesar de tener una importante incidencia en el desarrollo económico del país y de gozar de políticas de apoyo para su fortalecimiento, las MIPYMES se encuentran con una serie de factores, que dificultan su participación en las contrataciones menores del sector público; por lo tanto en este trabajo se realiza un análisis de las debilidades existentes, con el fin de aportar algunas sugerencias que contribuyan a irlas superando

Native Whey Induces Similar Adaptation to Strength Training as Milk, despite Higher Levels of Leucine, in Elderly Individuals

Background: Large amounts of protein (40 g) or supplementing suboptimal servings of protein with leucine are able to overcome the anabolic resistance in elderly muscle. Our aim was to compare the effects of supplementation of native whey, high in leucine, with milk on gains in muscle mass and strength during a period of strength training, in elderly individuals. Methods: In this double-blinded, randomized, controlled study, a total of 30 healthy men and women received two daily servings of 20 g of either milk protein or native whey, during an 11-week strength training intervention. Muscle strength, lean mass, m. vastus lateralis thickness, muscle fiber area, and resting and post-exercise phosphorylation of p70S6K, 4E-BP1, and eEF-2 were assessed prior to and after the intervention period. Results: Muscle mass and strength increased, by all measures applied in both groups (p 0.25). p70S6K phosphorylation increased (~1000%, p < 0.045) 2 h after exercise in the untrained and trained state, with no differences between supplements. Total and phosphorylated mTORC-1 decreased after training. Conclusion: Supplementation with milk or native whey during an 11-week strength training period increased muscle mass and strength similarly in healthy elderly individuals

Native Whey Induces Similar Adaptation to Strength Training as Milk, despite Higher Levels of Leucine, in Elderly Individuals

Background: Large amounts of protein (40 g) or supplementing suboptimal servings of protein with leucine are able to overcome the anabolic resistance in elderly muscle. Our aim was to compare the effects of supplementation of native whey, high in leucine, with milk on gains in muscle mass and strength during a period of strength training, in elderly individuals. Methods: In this double-blinded, randomized, controlled study, a total of 30 healthy men and women received two daily servings of 20 g of either milk protein or native whey, during an 11-week strength training intervention. Muscle strength, lean mass, m. vastus lateralis thickness, muscle fiber area, and resting and post-exercise phosphorylation of p70S6K, 4E-BP1, and eEF-2 were assessed prior to and after the intervention period. Results: Muscle mass and strength increased, by all measures applied in both groups (p 0.25). p70S6K phosphorylation increased (~1000%, p < 0.045) 2 h after exercise in the untrained and trained state, with no differences between supplements. Total and phosphorylated mTORC-1 decreased after training. Conclusion: Supplementation with milk or native whey during an 11-week strength training period increased muscle mass and strength similarly in healthy elderly individuals