Progressive strength training was performed 3 times a week for 8 weeks by 14 male students (19-31 yrs.). The training program consisted mainly of dynamic exercises for the leg extensors with maximal or close to maximal loads. The training caused significant improvements in dynamic and isometric strength. One repetition maximum in squats increased with 67%, Sargent jump with 22%, and maximal voluntary isometric contraction (MVC) with 13%, respectively. Body weight and leg muscle circumferences remained unchanged after training, whereas total body potassium, lean body mass and calculated total muscle mass increased, suggesting a change in body composition with training. Muscle biopsies were obtained from vastus lateralis for fibre analyses and determination of enzyme activities. There were no changes in muscle fibre composition or fibre area with training. The activities of Mg2+ stimulated ATPase, creatine phosphokinase and phosphofructokinase remained unchanged, whereas myokinase activity was increased after training from (1.41 to 1.52 moles x 10(-4) x g-1 x min-1, p less than 0.05). After training significant correlations (p less than 0.01) were demonstrated between Mg2+ stimulated ATPase activity and % fast twitch fibres (% FT) (r = 0.67), as well as between myokinase activity and % FT (r = 0.86).

The point prevalence of pSS was approximately seven times higher in the elderly population aged 71-74 years compared to individuals aged 40-44 years, regardless of the classification criteria used.

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BackgroundOverweight and obesity among adolescents are increasing worldwide. Risk factors include dietary intake characteristics and high levels of physical inactivity. In Sweden, few large comprehensive population-based surveys of dietary intake and lifestyle among adolescents have been carried out. Thus, the purpose of the current study was to describe dietary intake and food choices as well as leisure time activities in relation to overweight and obesity in a total sample of all schoolchildren aged 15 years in Western Sweden.MethodsIn 2008, a questionnaire was sent to all 21,651 adolescents born in 1992 in Västra Götaland Region, Sweden. Participation rate was 54.3 % (50.7 % girls/49.3 % boys). The questionnaire included a 73-item semi-quantitative food frequency questionnaire and questions on lifestyle. Results were evaluated against the Nordic Nutrition Recommendations and Swedish indicators of healthy diet and exercise habits. Associations with concurrent overweight and obesity were evaluated in multiple linear regression analysis.ResultsAmong girls, 49.5 % reached the goal of consuming fruit and vegetables at least daily, whereas for boys the figure was 34.4 %. Among both sexes, 15 % reached the goal of consuming fish at least twice weekly. Two-thirds of both sexes reached the goal of regular moderate or vigorous physical activity weekly. In total, 12.4 % were overweight and 2.4 % were obese. More girls than boys were underweight, whereas more boys than girls were overweight or obese (p < 0.001). Boys exhibited a more frequent intake of sodas and concentrated fruit juices, milk 3 % fat, bread and potatoes and fast food (p < 0.001). Frequent intake of candies and chocolate was reported by both sexes. Among girls and boys, living in rural areas, living in apartments and reporting no frequent leisure time physical activity were significant risk factors for being overweight or obese, also when adjusted for other risk factors.ConclusionsDietary habits of adolescents in Western Sweden warrant improvements. Public health actions should be taken to increase consumption of fruit, vegetables and fish, and decrease consumption of sodas and candies and also to increase frequency of physical activity. These actions may be helpful in reducing risks for overweight and obesity.

Relationship between isometric endurance performance at 50% of maximal voluntary isometric contraction (MCV) and skeletal muscle fibre composition has been elucidated in 19 physical education students. This was found to be linear and the equation corresponded to: y=9.35 + 1.093x; r=0.70 (endurance time expressed in seconds and fibre composition as percent slow twitch muscle fibres (ST) of the vastus lateralis muscle). As it is assumed from previous studies that similar isometric tensions preferentially recruit fast twitch muscle fibres (FT) and that the muscle at the point of exhaustion exhibits maximal values for lactate accumulation, it is suggested that lactate formed in FT fibres is released and stored in nonrecruited ST fibres. The ability to sustain similar isometric tension would then be depending on how large the fraction of ST fibres is that can serve as a lactaterecipient for lactate producing FT fibres.

Muscle biopsy samples were obtained from arm and leg muscles of endurance and strength trained athletes, respectively. Total LDH activity as well as occurrence and activity of LDH isozymes were determined. Comparing the results from the athletes with those from non-trained subjects with corresponding fibre compositions, it was found that the endurance athletes had a lower total LDH activity, a higher relative activity of the most heart-specific isozymes. LDH (1 + 2), and, on electrophoretic separation, a complete absence of LDH (4 + 5) in both arm and leg muscles. As compared to the untrained material the strength trained athletes tended to have a higher total LDH activity, a similar distribution of relative isozyme activities, and, in the leg muscles, a strong electrophoretic band corresponding to LDH 5, the most skeletal muscle specific isozyme.

1. The influence of ethanol administration on the metabolism of non-esterified fatty acids (NEFA) and on the utilization of blood-borne substrates and stored glycogen by leg muscles was examined in nine young healthy subjects at rest and during 40 min bicycle ergometer exercise at 50% of maximal capacity. Ethanol was administered by a constant-rate intravenous infusion (6 mmol/min), giving an arterial concentration within the range of 9·3–15·6 mmol/l. Turnover of NEFA and regional exchange were evaluated with [14C]oleic acid, and muscle metabolites were analysed from needle biopsy samples. 2. Leg blood flow was not altered by ethanol. Alanine in arterial blood was reduced by approximately 25% after ethanol administration during exercise. A slight decrease in the concentration of NEFA in arterial plasma was observed after ethanol, associated with an increase in the fractional turnover of oleic acid, indicating an increased removal of NEFA from the plasma. The rate of uptake of NEFA in the leg was only slightly decreased. 3. The total glycogen depletion in leg muscle during exercise was not influenced by ethanol. The pattern of glycogen utilization in different muscle fibres was changed by ethanol and found to be dependent on the fibre composition of the respective subject. In the control experiments, but not after ethanol administration, a negative correlation was observed between glycogen utilization during exercise and the fraction of type I fibres. 4. It is concluded that ethanol administration during exercise (a) decreases leg uptake of NEFA due to a lower concentration of NEFA in plasma, although this lower uptake is compensated by an increased fractional oxidation, (b) does not influence total glycogen depletion in leg muscle, (c) changes the pattern of glycogen utilization in different muscle fibres, (d) influences only to a small extent the energy supply to working muscles, the most predominant isolated effect being on inhibition of the lactate release.

tHcy in middle-aged women is an independent risk factor for LIs, but not WMLs, as observed using CT later in life.