Stretching exercises are commonly used as an integral part of a pre-exercise warm-up training sessions despite even early laboratory studies having demonstrated that some degree of mechanical weakness takes place following the stretching of muscle tissue. This study compared the effects of four treatments (n = 12 each) [10 minutes of quiet sitting, without stretching (NS); two minutes warm up on an arm ergometer at 25 watts resistance (WU); 10 second-hold static stretching (each) of the shoulder, chest and arm muscle groups (ST10); and two sets of 20 second-hold static stretching (each) of the shoulder, chest and upper-arm muscle groups (ST20)] on a 1-RM bench press in 48 subjects who were matched for their pre-test 1-RM bench press values. The mean 1-RM bench press values following ST10 (45.0 ± 9.9 kg) and WU (48.9 ± 10.5 kg) treatments were significantly (p ? 0.05) higher at the post-test than at the pre-test 1-RM (43.9 ± 10.1 kg and 43.9 ± 10. kg, respectively). The mean 1-RM values following the ST20 treatment was significantly lower (41.9 ± 10.0 kg) than at pre-test (43.9 ± 10.1 kg). However, multiple comparisons and Analysis of Variance (ANOVA) statistical procedures demonstrated that there was no significant difference from pre- to post-test between the four groups. These findings suggest that the use of stretching activities prior to events requiring maximal force production may not be obligatory or may even be contraindicated since the effects of stretching are then to decrease the amount of force that can be produced via the natural elastic components of the muscle and tendons and via the stretch reflex.

Abstract Stretching exercises are commonly used as an integral part of a pre-exercise warm-up training sessions despite even early laboratory studies having demonstrated that some degree of mechanical weakness takes place following the stretching of muscle tissue. This study compared the effects of four treatments (n = 12 each) [10 minutes of quiet sitting, without stretching (NS); two minutes warm up on an arm ergometer at 25 watts resistance (WU); 10 second-hold static stretching (each) of the shoulder, chest and arm muscle groups (ST10); and two sets of 20 second-hold static stretching (each) of the shoulder, chest and upper-arm muscle groups (ST20)] on a 1-RM bench press in 48 subjects who were matched for their pre-test 1-RM bench press values. The mean 1-RM bench press values following ST10 (45.0 ± 9.9 kg) and WU (48.9 ± 10.5 kg) treatments were significantly (p ? 0.05) higher at the post-test than at the pre-test 1-RM (43.9 ± 10.1 kg and 43.9 ± 10. kg, respectively). The mean 1-RM values following the ST20 treatment was significantly lower (41.9 ± 10.0 kg) than at pre-test (43.9 ± 10.1 kg). However, multiple comparisons and Analysis of Variance (ANOVA) statistical procedures demonstrated that there was no significant difference from pre- to post-test between the four groups. These findings suggest that the use of stretching activities prior to events requiring maximal force production may not be obligatory or may even be contraindicated since the effects of stretching are then to decrease the amount of force that can be produced via the natural elastic components of the muscle and tendons and via the stretch reflex.

Muskelstyrka är av stort värde för att bibehålla god hållning och aktivitetsnivå i såväl dagliga livet som i idrottssammanhang. Styrketräning har visats vara ett utmärkt sätt att uppnå styrka. De gamla teorierna om hur man på bästa sätt bedriver styrketräning har på senare år utmanats av studier som visar att man kan uppnå likvärdiga resultat med lågintensiv styrketräning till utmattning som med högintensiv sådan. Dessa studier har dock begränsats till otränade individer. Syfte: Att belysa hur intensiteten påverkar muskelstyrkan hos tränade individer. Metod: Litteratursökning i PubMed, SportsDiscus and Cinahl. Sju artiklar inkluderades genom granskning enligt PEDro scale. Resultat: Resultaten av denna review är ofullständiga till följd av begränsad statistisk power för styrkeökning i de inkluderade artiklarna. Ingen artikel undersökte en låg-intensitets interventionsgrupp. Det tycks föreligga en liten fördel för träning med belastning motsvarande 2 – 5 RM jämfört med 8 – 12 RM vid bänkpress. Slutsats: Det går inte utifrån denna litteraturstudie att dra några egentliga slutsatser om intensitetens betydelse för tränade individer, det behövs fler studier av god kvalitet. / Muscle strength is important to maintain a good posture and activity-level in sport as well as in daily life. Resistance training has been shown to be a good way to achieve that strength. The old theories of how to perform resistance training in an optimal way have recently been challenged by studies concluding that resistance training with low intensity to exhaustion or fatigue can give almost the same results as training with high intensity. However, these studies have been made on untrained subjects. Aim: The purpose of this review was to highlight the influence of intensity on muscle strength on trained subjects. Method: Literature search in PubMed, SportsDiscus and Cinahl. Seven articles were selected for reviewing using PEDro scale. Results: The results of this study are inconclusive due to lack of high statistical power for strength gain in included articles. None of the included articles had a real low intensity intervention. A small advantage can be seen for training with loads of 2 - 5 RM compared to 8 – 12 RM in bench press training. Conclusions: There are no direct conclusions to be drawn from this review, more studies of god quality are needed.

O objetivo desse estudo foi avaliar a influência da variabilidade da intensidade e do exercício no treinamento de força nos ganhos de força e área de secção transversa (AST). Quarenta e nove sujeitos destreinados e do sexo masculino foram divididos em cinco grupos: intensidade constante exercício variado (ICEV), intensidade constante exercício constante (ICEC), intensidade variada exercício variado (IVEV), intensidade variada exercício constante (IVEC) e controle (C). Foi realizado treinamento de força para membros inferiores durante doze semanas. A força máxima foi avaliada por meio do teste de uma repetição máxima (1RM) no agachamento e a AST do músculo quadríceps femural aferida por ressonância magnética. Todos os grupos obtiveram ganhos significativos em relação à condição pré-treinamento tanto de força máxima quanto de AST (P < 0,05). Não houve diferença significativa entre os grupos para ambas variáveis. A inclusão da variação do exercício isoladamente ou combinada com a variação da intensidade no estímulo do treinamento de força parece não trazer benefícios adicionais para o ganho de força e AST. Contudo, a variação da intensidade somente pode não ser a estratégia mais indicada quando o objetivo é gerar força em sujeitos destreinados em um período de doze semanas / The aim of this study was to evaluate the variability of intensity and exercise of the strength training on strength gains and muscle cross-sectional area (CSA). Forty-nine untrained male subjects were divided into five groups: constant exercise-varied intensity (ICEV), constant intensity-constant exercise (ICEC), varied exercise-varied intensity (IVEV), varying intensity- constant exercise (IVECO) and control (C). Strength training for the lower limbs was performed for twelve weeks. The maximal strength was assessed using the squat one repetition maximum test (1RM) and quadriceps femoris muscle CSA measured by MRI. All groups had significant gains both in maximum strength and CSA in relation to the pre-training (P <0.05). There were no significant differences between groups for both variables. On the IVEC group did not differ the maximum strength values from the control group at the post-test (P>0.05). The inclusion of the variation of exercise alone or combined with the variation in the stimulus intensity during a strength training program appears to produce no additional gains in strength and AST. However, the variation of intensity only may not be the best strategy when the objective is to increase strength in untrained subjects in a period of twelve weeks

O objetivo desse estudo foi avaliar a influência da variabilidade da intensidade e do exercício no treinamento de força nos ganhos de força e área de secção transversa (AST). Quarenta e nove sujeitos destreinados e do sexo masculino foram divididos em cinco grupos: intensidade constante exercício variado (ICEV), intensidade constante exercício constante (ICEC), intensidade variada exercício variado (IVEV), intensidade variada exercício constante (IVEC) e controle (C). Foi realizado treinamento de força para membros inferiores durante doze semanas. A força máxima foi avaliada por meio do teste de uma repetição máxima (1RM) no agachamento e a AST do músculo quadríceps femural aferida por ressonância magnética. Todos os grupos obtiveram ganhos significativos em relação à condição pré-treinamento tanto de força máxima quanto de AST (P < 0,05). Não houve diferença significativa entre os grupos para ambas variáveis. A inclusão da variação do exercício isoladamente ou combinada com a variação da intensidade no estímulo do treinamento de força parece não trazer benefícios adicionais para o ganho de força e AST. Contudo, a variação da intensidade somente pode não ser a estratégia mais indicada quando o objetivo é gerar força em sujeitos destreinados em um período de doze semanas / The aim of this study was to evaluate the variability of intensity and exercise of the strength training on strength gains and muscle cross-sectional area (CSA). Forty-nine untrained male subjects were divided into five groups: constant exercise-varied intensity (ICEV), constant intensity-constant exercise (ICEC), varied exercise-varied intensity (IVEV), varying intensity- constant exercise (IVECO) and control (C). Strength training for the lower limbs was performed for twelve weeks. The maximal strength was assessed using the squat one repetition maximum test (1RM) and quadriceps femoris muscle CSA measured by MRI. All groups had significant gains both in maximum strength and CSA in relation to the pre-training (P <0.05). There were no significant differences between groups for both variables. On the IVEC group did not differ the maximum strength values from the control group at the post-test (P>0.05). The inclusion of the variation of exercise alone or combined with the variation in the stimulus intensity during a strength training program appears to produce no additional gains in strength and AST. However, the variation of intensity only may not be the best strategy when the objective is to increase strength in untrained subjects in a period of twelve weeks

Introduction: Creatine is naturally found in our bodys and converts stored energy into kinetic energy. Higher levels of creatine gives more fuel to perform high intensity training that's why creatine is claimed to have an effect on our training results. Purpose: The purpose of this narrative literature study is to summarize and review the latest research regarding the effects of creatine on muscle strenght for different individuals and what is optimal dosage? Method: To find relevant articles the database pubmed was used. After the titles and abstracts were read carefully ten articles were included to be used for this study. Results: 8/10 studys shows significantly better results for individuals using creatine compared to the control group when it comes to muscle strenght for young individuals. Effect on muscle strength is already proven after low doses of creatine such as 2 grams a day. Conclusion: Creatine as a supplement seems to have a positive effect on muscle strength with a low risk of side effects. Younger people seem to get the best effect from creatine, while the effect for older people can be questioned. Optimal dosage for best effect is something that needs to be studied further.

Nutrition and recovery go hand in hand. After a resistance training workout, it is extremely important for athletes to rebuild and refuel their bodies with the proper nourishment to obtain maximal results. In doing so, they consume different recovery aids or ergogenic aids for gains in muscle mass, an aid in hydration, and a speedy recovery. Ergogenic aids can include many things (i.e., improved equipment, training program), but one of the most popular types of ergogenic aids is nutritional supplements such as protein, carbohydrates, creatine, and vitamins. A nutritional supplement that has recently grown in popularity is chocolate milk. Currently, no studies exist comparing the effects of fat-free chocolate milk and 2% chocolate milk on muscular strength and body composition in collegiate softball players. The purpose of this study will be to determine the effects of fat-free and 2% chocolate milk ingestion on body composition and muscular strength following eight weeks of resistance training. In a randomized (matched according to strength and bodyweight), double blind experimental design, 18 female, collegiate softball players (18.5 +_ .7 yrs; 65.7 +_ 1.8 inches; 156.2 +_ 21.6 lbs) ingested either fat-free chocolate milk or 2% chocolate milk immediately after resistance exercise workouts for an 8-week period. Dependent variables included body fat percentage, lean muscle mass, bench press 1RM, and leg press 1RM. Data was analyzed via a paired samples t-test (to detect difference across both groups over the 8-week training period) and an independent samples t-test (to detect differences between the groups) using SPSS for Windows 15.0. No statistically significant differences were found in bench press strength, leg press strength, body fat %, and lean body mass between the fat-free group and the 2% chocolate milk group. The major finding of this study is that there is no difference between fat-free chocolate milk and 2% chocolate milk in regards to body fat percentage, lean body mass, bench press maximal strength, and leg press maximal strength following an eight week exercise program where the chocolate milk was ingested immediately after each workout. However, there was a significant difference in both groups combined after the eight week training program. Therefore, from a practical sense, consumption of either fat-free chocolate milk or 2% chocolate milk in conjunction with a periodized resistance training program does improve exercise performance in regards to maximal strength as well as improvements in body fat percentage and lean body mass.

Propósito: Observar obesas pré e pós-dieta hipocalórica moderada, mais treinamento em circuito ou caminhada. quanto a variáveis nutricionais. Métodos: Grupos: treinamento em circuito, CIRC, n = 26, índice de massa corporal (IMC, kg/m2) = 33,2 ± 7,9 (Média±desvio padrão); idade = 32,6 ± 9,7 anos; e treinamento em caminhada, CAM, n = 24, IMC = 29,2±3,4; idade = 38,8 ± 10,5 anos. Avaliações: a composição corporal, coleta de urina e sangue, calorimetria indireta e testes físicos eram obtidos no inicio (M1) e final (M2) do estudo. Treinamento: mês 1 = 1 h x 3 d/semana; e mês 2 = 1 h x 4 d/semana. Dieta: foi adaptada do registro alimentar de uma semana, ajustado ao gasto energético de repouso (GER) e balanceada, com a seguinte proporção: 20% de proteínas; 20% de gorduras; e 60% de carbohidratos. Resultados: Pré-intervenção: 76% tinham algum familiar obeso; havia sintomatologia indicativa de: 60% ansiosas, 12% depressivas, 34% compulsivas e 32% distúrbio do sono, avaliadas por questionário no exame clínico. Foram encontrados níveis alterados de colesterol total (CT, mg/dL), e ou frações em 22% das sujeitas. O peso, IMC, o índice abdômem/quadril (IAQ), a soma de oito pregas cutâneas (SP8) se correlacionaram significativamente a quatro variáveis bioquímicas, e a circunferência do abdômen (CAb), e o percentual de gordura por antropometria (%GAntro) a cinco. Intervenção: O peso, IMC, %GAntro, endomorfia, massa gorda por bioimpedância (MGBia) e percentual de gordura por bioimpedância (%GBia), foram reduzidos significativamente nos dois grupos. O CIRC melhorou significativamente em todos (seis) e o CAM em três testes físicos. O CIRC teve significância para: ¯glicose (Gli), ¯AU, ¯CT, ¯Tg (todos em mg/dL), ­glóbulos vermelhos (GV) (mm3) e ­hematócrito (Ht) (%); e o CAM para: ¯Gli, ¯AU, ¯HDL, ­CT/HDL, ­GV, ­Ht. O GER não teve diferença em ambos os grupos. Conclusões: Pré-intervenção: Os dados antropometricos indicam boa correlação com os fatores bioquímicos de risco, mas não tem uma tendência constante. A taxa CT/HDL apresentou correlação com todas as medidas antropométircas e a Gli com nenhuma. A obesidade destas mulheres parece ter múltiplos fatores e o estilo de vida papel determinante. Intervenção: A atividade física per se foi importante para causar modificações nutricionais e da composição corporal nestas obesas. O CIRC teve melhor associação com o incremento da performance física e dados bioquímicos sanguineos e ambos os grupos preservaram o GER. / Purpose: To observe obese women before and after a low-calorie diet plus circuit training or jogging regarding nutritional parameters. Methods: Groups: circuit training, CIRC, n = 26, body mass index (BMI, kg/m2) = 33.2 ± 7.9 (Mean±SD), age = 32.6 ± 9.7 years; and jogging training, JOGG, n = 24, BMI = 29.2 ± 3.4; age = 38.8 ± 10.5 years. Evaluations: body composition, collection of urine and blood samples, indirect calorimetry and physical tests were performed at the beginning (M1) and at the end (M2) of the study. Training: month one: 1 h x 3 d/week; month two: 1 h x 4 d/week. Diet: was adapted on the basis of a one week feeding record feed and adjusted to the resting metabolic rate (RMR) measured by indirect calorimetry, with the following proportion: 20% protein, 20% fat; and 60% carbohydrate. Results: Pre-intervention: 76% had one or more obese family members; there were symptoms indicating that 60% were anxious, 12% depressive, 34% compulsive, and 32% had sleep disorders, evaluated by a questionnaire during clinical examination. Altered levels of total cholesterol (TC) and/or fractions were found in 22% of the subjects. Weight (W), BMI, waist/hip ratio (WHR), and the sum of eight skin folds (8SF), were significantly correlated with four biochemistry variables, and abdominal circumference (AbC), and anthropometric fat percentage (%FAnthro) were correlated with five. Intervention: Weight, BMI, %FAnthro, endomorphy, body fat mass by bioimpedance (BFMBia) and percent body fat by bioimpedance (%FBia) were reduced in both groups. CIRC significantly increased performance in all (six) tests and the JOGG in three physical tests. CIRC showed significant differences for: ¯glucose (Glu), ¯UA, ¯TC (TC), ¯Tg (all in mg/dL), ­red blood cells (RBC) (mm3) and ­hematocrit (Ht) (%); and JOGG for: ¯Glu, ¯UA, ¯HDL, ­CT/HDL, ­RBC, ­Ht. The RMR was not significantly reduced in both groups. Conclusions: Pre-intervention: Anthropometric data indicated a good correlation with biochemical factors, but did not show a constant tendency. CT/HDL showed correlation with all anthropometric measurements and Glu with none. The obesity of these women appears to have multiple factors, with life style playing a determinant role. Intervention: Physical activities were determined to favor body composition, reduced weight and blood markers. CIRC were better in terms of physical performance and blood markers. Both types of training were sufficient to prevent a fall of RMR.

Propósito: Observar obesas pré e pós-dieta hipocalórica moderada, mais treinamento em circuito ou caminhada. quanto a variáveis nutricionais. Métodos: Grupos: treinamento em circuito, CIRC, n = 26, índice de massa corporal (IMC, kg/m2) = 33,2 ± 7,9 (Média±desvio padrão); idade = 32,6 ± 9,7 anos; e treinamento em caminhada, CAM, n = 24, IMC = 29,2±3,4; idade = 38,8 ± 10,5 anos. Avaliações: a composição corporal, coleta de urina e sangue, calorimetria indireta e testes físicos eram obtidos no inicio (M1) e final (M2) do estudo. Treinamento: mês 1 = 1 h x 3 d/semana; e mês 2 = 1 h x 4 d/semana. Dieta: foi adaptada do registro alimentar de uma semana, ajustado ao gasto energético de repouso (GER) e balanceada, com a seguinte proporção: 20% de proteínas; 20% de gorduras; e 60% de carbohidratos. Resultados: Pré-intervenção: 76% tinham algum familiar obeso; havia sintomatologia indicativa de: 60% ansiosas, 12% depressivas, 34% compulsivas e 32% distúrbio do sono, avaliadas por questionário no exame clínico. Foram encontrados níveis alterados de colesterol total (CT, mg/dL), e ou frações em 22% das sujeitas. O peso, IMC, o índice abdômem/quadril (IAQ), a soma de oito pregas cutâneas (SP8) se correlacionaram significativamente a quatro variáveis bioquímicas, e a circunferência do abdômen (CAb), e o percentual de gordura por antropometria (%GAntro) a cinco. Intervenção: O peso, IMC, %GAntro, endomorfia, massa gorda por bioimpedância (MGBia) e percentual de gordura por bioimpedância (%GBia), foram reduzidos significativamente nos dois grupos. O CIRC melhorou significativamente em todos (seis) e o CAM em três testes físicos. O CIRC teve significância para: ¯glicose (Gli), ¯AU, ¯CT, ¯Tg (todos em mg/dL), ­glóbulos vermelhos (GV) (mm3) e ­hematócrito (Ht) (%); e o CAM para: ¯Gli, ¯AU, ¯HDL, ­CT/HDL, ­GV, ­Ht. O GER não teve diferença em ambos os grupos. Conclusões: Pré-intervenção: Os dados antropometricos indicam boa correlação com os fatores bioquímicos de risco, mas não tem uma tendência constante. A taxa CT/HDL apresentou correlação com todas as medidas antropométircas e a Gli com nenhuma. A obesidade destas mulheres parece ter múltiplos fatores e o estilo de vida papel determinante. Intervenção: A atividade física per se foi importante para causar modificações nutricionais e da composição corporal nestas obesas. O CIRC teve melhor associação com o incremento da performance física e dados bioquímicos sanguineos e ambos os grupos preservaram o GER. / Purpose: To observe obese women before and after a low-calorie diet plus circuit training or jogging regarding nutritional parameters. Methods: Groups: circuit training, CIRC, n = 26, body mass index (BMI, kg/m2) = 33.2 ± 7.9 (Mean±SD), age = 32.6 ± 9.7 years; and jogging training, JOGG, n = 24, BMI = 29.2 ± 3.4; age = 38.8 ± 10.5 years. Evaluations: body composition, collection of urine and blood samples, indirect calorimetry and physical tests were performed at the beginning (M1) and at the end (M2) of the study. Training: month one: 1 h x 3 d/week; month two: 1 h x 4 d/week. Diet: was adapted on the basis of a one week feeding record feed and adjusted to the resting metabolic rate (RMR) measured by indirect calorimetry, with the following proportion: 20% protein, 20% fat; and 60% carbohydrate. Results: Pre-intervention: 76% had one or more obese family members; there were symptoms indicating that 60% were anxious, 12% depressive, 34% compulsive, and 32% had sleep disorders, evaluated by a questionnaire during clinical examination. Altered levels of total cholesterol (TC) and/or fractions were found in 22% of the subjects. Weight (W), BMI, waist/hip ratio (WHR), and the sum of eight skin folds (8SF), were significantly correlated with four biochemistry variables, and abdominal circumference (AbC), and anthropometric fat percentage (%FAnthro) were correlated with five. Intervention: Weight, BMI, %FAnthro, endomorphy, body fat mass by bioimpedance (BFMBia) and percent body fat by bioimpedance (%FBia) were reduced in both groups. CIRC significantly increased performance in all (six) tests and the JOGG in three physical tests. CIRC showed significant differences for: ¯glucose (Glu), ¯UA, ¯TC (TC), ¯Tg (all in mg/dL), ­red blood cells (RBC) (mm3) and ­hematocrit (Ht) (%); and JOGG for: ¯Glu, ¯UA, ¯HDL, ­CT/HDL, ­RBC, ­Ht. The RMR was not significantly reduced in both groups. Conclusions: Pre-intervention: Anthropometric data indicated a good correlation with biochemical factors, but did not show a constant tendency. CT/HDL showed correlation with all anthropometric measurements and Glu with none. The obesity of these women appears to have multiple factors, with life style playing a determinant role. Intervention: Physical activities were determined to favor body composition, reduced weight and blood markers. CIRC were better in terms of physical performance and blood markers. Both types of training were sufficient to prevent a fall of RMR.

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