Biomedical subjects

Truls Raastad

Publications and source records attributed to Truls Raastad.

7 recordsLinked to original sources

PubMed2006

Promoting physical activity in a low-income multiethnic district: effects of a community intervention study to reduce risk factors for type 2 diabetes and cardiovascular disease: a community intervention reducing inactivity.

OBJECTIVE: The aim was to assess the net effects on risk factors for type 2 diabetes and cardiovascular disease of a community-based 3-year intervention to increase physical activity. RESEARCH DESIGN AND METHODS: A pseudo-experimental cohort design was used to compare changes in risk factors from an intervention and a control district with similar socioeconomic status in Oslo, Norway, using a baseline investigation of 2,950 30- to 67-year-old participants and a follow-up investigation of 1,776 (67% of those eligible, 56% women, 18% non-Western immigrants) participants. A set of theory-based activities to promote physical activity were implemented and tailored toward groups with different psychosocial readiness for change. All results reported are net changes (the difference between changes in the intervention and control districts). At both surveys, the nonfasting serum levels of lipids and glucose were adjusted for time since last meal. RESULTS: The increase in physical activity measured by two self-reported questionnaires was 9.5% (P = 0.008) and 8.1% (P = 0.02), respectively. The proportion who increased their body mass was 14.2% lower in the intervention district (P < 0.001), implying a 50% relative reduction compared with the control district, and was lower across subgroups. Beneficial effects were seen for triglyceride levels (0.16 mmol/l [95% CI 0.06-0.25], P = 0.002), cholesterol-to-HDL cholesterol ratio (0.12 [0.03-0.20], P = 0.007), systolic blood pressure (3.6 mmHg [2.2-4.8], P < 0.001), and for men also in glucose levels (0.35 mmol/l [0.03-0.67], P = 0.03). The net proportion who were quitting smoking was 2.9% (0.1-5.7, P = 0.043). CONCLUSIONS: Through a theory-driven, low-cost, population-based intervention program, we observed an increase in physical activity levels, reduced weight gain, and beneficial changes in other risk factors for type 2 diabetes and cardiovascular disease.

Adult↗

PubMed2005

Delayed leukocytosis and cytokine response to high-force eccentric exercise.

PURPOSE: Delayed leukocytosis after strenuous exercise is well documented, but the underlying mechanisms are not clear. In this study, we investigated the relationship between exercise-induced muscle damage and delayed leukocytosis, by utilizing an extreme eccentric exercise protocol. METHODS: We obtained blood samples from 11 healthy men before and after 300 maximal eccentric actions with m. quadriceps. Maximal force-generating capacity was tested before and regularly during the 7 d after exercise. Blood was analyzed for leukocytes, growth hormone (GH), cortisol, granulocyte colony-stimulating factor (G-CSF), macrophage colony-stimulating factor (M-CSF), interleukin (IL)-6, IL-8, monocyte chemoattractant protein-1 (MCP-1), macrophage inflammatory protein-1beta (MIP-1beta), creatine kinase (CK), C-reactive protein (CRP), complement activation products (C3bc and the terminal complement complex (TCC)), and chemotactic activity in plasma. RESULTS: The force-generating capacity was reduced by 47 +/- 5% (mean +/- SEM) immediately after exercise. Blood concentration of neutrophils and monocytes and the plasma concentration of G-CSF, IL-6, and MCP-1 peaked 6 h after exercise, whereas M-CSF peaked immediately after exercise. Serum concentration of GH and cortisol also peaked immediately after exercise, whereas the serum concentration of CRP and CK peaked after 2 and 4 d, respectively. At 1 h after exercise, chemotactic activity in plasma was increased; at the same time, concentration of C3bc and TCC were decreased. A positive correlation was found between the acute loss of force and the delayed leukocytosis (r = 0.66; P < 0.05), between peak G-CSF and the delayed neutrophilia (r = 0.65, P < 0.05), between acute loss of force and changes in CK (r = 0.65, P < 0.05), between acute loss of force and changes in CRP (r = 0.65, P < 0.05), and between changes in GH and monocyte blood concentrations (r = 0.68, P < 0.05). CONCLUSION: The degree of exercise-induced muscle damage seems to be reflected by the magnitude of the subsequent delayed leukocytosis. The signal between the exercised muscle and bone marrow must be investigated further, but G-CSF and GH are putative mobilizing factors.

Adult↗

PubMed2004

A 10-week randomized trial comparing eccentric vs. concentric hamstring strength training in well-trained soccer players.

PURPOSE: To compare the effects of a 10-week training program with two different exercises -- traditional hamstring curl (HC) and Nordic hamstrings (NH), a partner exercise focusing the eccentric phase -- on muscle strength among male soccer players. METHODS: Subjects were 21 well-trained players who were randomized to NH training (n = 11) or HC training (n = 10). The programs were similar, with a gradual increase in the number of repetitions from two sets of six reps to three sets of eight to 12 reps over 4 weeks, and then increasing load during the final 6 weeks of training. Strength was measured as maximal torque on a Cybex dynamometer before and after the training period. RESULTS: In the NH group, there was an 11% increase in eccentric hamstring torque measured at 60 degrees s(-1), as well as a 7% increase in isometric hamstring strength at 90 degrees, 60 degrees and 30 degrees of knee flexion. Since there was no effect on concentric quadriceps strength, there was a significant increase in the hamstrings:quadriceps ratio from 0.89 +/- 0.12 to 0.98 +/- 0.17 (11%) in the NH group. No changes were observed in the HC group. CONCLUSION: NH training for 10 weeks more effectively develops maximal eccentric hamstring strength in well-trained soccer players than a comparable program based on traditional HC.

Adult↗

PubMed2003

Delayed leukocytosis after hard strength and endurance exercise: aspects of regulatory mechanisms.

BACKGROUND: During infections, polymorphonuclear neutrophilic granulocytes (PMN) are mobilized from their bone marrow stores, travel with blood to the affected tissue, and kill invading microbes there. The signal(s) from the inflammatory site to the marrow are unknown, even though a number of humoral factors that can mobilize PMN, are well known. We have employed a standardized, non-infectious human model to elucidate relevant PMN mobilizers. Well-trained athletes performed a 60-min strenuous strength workout of leg muscles. Blood samples were drawn before, during and just after exercise, and then repeatedly during the following day. Cortisol, GH, ACTH, complement factors, high-sensitive CRP (muCRP), IL-6, G-CSF, IL-8 (CXCL8) and MIP-1beta (CCL4) were measured in blood samples. PMN chemotaxins in test plasma was assessed with a micropore membrane technique. RESULTS: About 5 hr after the workout, blood granulocytosis peaked to about 150% of baseline. Plasma levels of GH increased significantly 30 min into and 5 min after the exercise, but no increase was recorded for the other hormones. No significant correlation was found between concentrations of stress hormones and the subjects' later occurring PMN increases above their individual baselines. Plasma G-CSF increased significantly - but within the normal range - 65 min after the workout. IL-6 increased very slightly within the normal range, and the chemokines IL-8 and MIP-1beta did not increase consistently. However, we found a significant increase of hitherto non-identified PMN-chemotactic activity in plasma 35, 50, and 60 min after the exercise. No systemic complement activation was detected, and (mu)CRP was within the reference range at rest, 5 h and 23 h after the exercise. After endurance exercise, similar findings were made, except for a cortisol response, especially from non-elite runners. CONCLUSION: Apparently, a multitude of humoral factors can - directly or indirectly - mobilize PMN from marrow to blood; some of the factors are, others are not known to be, chemotactic. Under different conditions, different selections of these mobilizers may be used. In the late granulocytosis after heavy, long-lasting exercise a number of factors thought capable of mimicking the granulocytosis of infectious diseases were apparently irrelevant.

Adult↗

PubMed2003

Temporal relation between leukocyte accumulation in muscles and halted recovery 10-20 h after strength exercise.

Effects of normal strength exercise on leukocyte accumulation were examined in 10 well-trained male subjects (27.2 +/- 2.7 yr). The workout, consisting of five maximal sets of three repetitions of leg press exercise and five maximal sets of six repetitions of knee extension exercise, was performed with the dominant leg, and the other leg served as control. Repeated maximal isokinetic knee extensions at 60 degrees /s were performed to evaluate neuromuscular fatigue and recovery after the workout. Accumulation of leukocytes was assessed with 99mTc-labeled cells, and repeated images of the thighs were taken 1-24 h after the workout. Maximal force-generating capacity in the exercised leg was reduced by 17 +/- 2% (P < 0.01) after the workout. The course of recovery followed a biphasic pattern characterized by halted recovery 10-23 h after exercise. The presence of leukocytes was approximately 10% higher in the exercised than in the control thigh 10 h after exercise (P < 0.05). This difference increased to approximately 15% at 20 h after exercise (P < 0.05). The retarded recovery of maximal force-generating capacity 10-20 h after exercise, together with a significant infiltration of leukocytes in exercised muscle during the same time interval, shows a temporal relation between leukocyte infiltration and impaired recovery.

Adult↗

PubMed2003

Promoting physical activity in a multi-ethnic district - methods and baseline results of a pseudo-experimental intervention study.

BACKGROUND AND DESIGN: A combined community and high-risk intervention study of three years duration started in one district in Oslo after a baseline health survey in two multi-ethnic and low socio-economic status (SES) districts, using a pseudo-experimental design with an age-matched sample from the other district as controls. The intervention focused on promoting physical activity to reduce the burden of type 2 diabetes and cardiovascular disease (CVD). METHODS: A total of 6140 subjects were invited to participate (age group: 31-67). Data on health status and health-related behaviours, collected via standardized questionnaires, physical examinations and blood sample analyses, were available for 2950 persons (attendance rate 48%), whereas official statistics were available for the invited population. RESULTS: The prevalence of self-reported diabetes was 5.1% in men and 3.5% in women, but the total diabetes prevalence was 9% for men and 5.1% for women. One-third of the population were sedentary in their leisure time, men more than women (38% versus 29%). The prevalence of obesity did not differ between the genders (21% had BMI 30 kg/m(2)). The relatively high mean scores on most psychosocial variables related to physical activity, especially among women, indicate a high motivational readiness for increase in physical activity behaviour. The baseline data, for example on the prevalence of chronic diseases were similar in the two districts. CONCLUSION: The prevalence of self-reported diabetes is remarkably higher than reported from other studies in Norway. The proportion of undiagnosed diabetes was higher than anticipated, and constituted 39% of all those categorized as diabetics.

Cardiovascular Diseases↗

PubMed2003

The influence of volume of exercise on early adaptations to strength training.

The purpose of this investigation was to compare the effects of single-set strength training and 3-set strength training during the early phase of adaptation in 18 untrained male subjects (age, 20-30 years). After initial testing, subjects were randomly assigned to either the 3L-1U group (n = 8), which trained 3 sets in leg exercises and 1 set in upper-body exercises, or the 1L-3U group (n = 10), which trained 1 set in leg exercises and 3 sets in upper-body exercises. Testing was conducted at the beginning and at the end of the study and consisted of 2 maximal isometric tests (knee extension and bench press) and 6 maximal dynamic tests (1 repetition maximum [1RM] tests). Subjects trained 3 days per week for 6 weeks. After warm-up, subjects performed 3 leg exercises and 4 upper-body exercises. In both groups, each set consisted of 7 repetitions (reps) with the load supposed to induce muscular failure after the seventh rep (7RM load). After 6 weeks of training, 1RM performance in all training exercises was significantly increased (10-26%, p < 0.01) in both groups. The relative increase in 1RM load in the 3 leg exercises was significantly greater in the 3L-1U group than in the 1L-3U group (21% vs. 14%, p = 0.01). However, the relative increase in 1RM load in the 3 upper-body exercises was similar in the 3L-1U group (16%) and the 1L-3U group (14%). These results show a superior adaptation to 3-set strength training, compared with 1-set strength training, in leg exercises but not in upper-body exercises during the early phase of adaptation.

Adaptation, Physiological↗