Does core strength training influence kinetic efficiency, lower extremity stability, and 5000m performance in runners?

Context: Core strength training (CST) has been popular in the fitness industry for a decade. Although strong core muscles are believed to enhance athletic performance, only few scientific studies have been conducted to identify the effectiveness of CST on improving athletic performance. Objective: Identify the effects of a 6-wk CST on running kinetics, lower extremity stability, and running performance in recreational and competitive runners. Design and Setting: A test-retest, randomized control design was used to assess the effect of CST and no CST on ground reaction force (GRF), lower extremity stability scores, and running performance. Participants: Twenty-eight healthy adults (age, 36.9+9.4yrs, height, 168.4+9.6cm, mass, 70.1+15.3kg) were recruited and randomly divided into two groups. Main outcome Measures: GRF was determined by calculating peak impact vertical GRF (vGRF), peak active vGRF, duration of the breaking or horizontal GRF (hGRF), and duration of the propulsive hGRF as measured while running across a force plate. Lower extremity stability in three directions (anterior, posterior, lateral) was assessed using the Star Excursion Balance Test (SEBT). Running performance was determined by 5000 meter run measured on selected outdoor tracks. Six 2 (time) X 2 (condition) mixed-design ANOVA were used to determine if CST influences on each dependent variable, p < .05. Results: No significant interactions were found for any kinetic variables and SEBT score, p>.05. But 5000m run time showed significant interaction, p < .05. SEBT scores improved in both groups, but more in the experimental group. Conclusion: CST did not significantly influence kinetic efficiency and lower extremity stability, but did influence running performance.

Physical activity in the school setting: cognitive performance is not affected by three different types of acute exercise

Recent studies indicate that a single bout of physical exercise can have immediatepositive effects on cognitive performance of children and adolescents. However, thetype of exercise that affects cognitive performance the most in young adolescents isnot fully understood. Therefore, this controlled study examined the acute effects ofthree types of 12-min classroom-based exercise sessions on information processingspeed and selective attention. The three conditions consisted of aerobic, coordination,and strength exercises, respectively. In particular, this study focused on the feasibilityand efficiency of introducing short bouts of exercise in the classroom. One hundredand ninety five students (5th and 6th grade; 10–13 years old) participated in a doublebaseline within-subjects design, with students acting as their own control. Exercise typewas randomly assigned to each class and acted as between-subject factor. Before andimmediately after both the control and the exercise session, students performed twocognitive tests that measured information processing speed (Letter Digit SubstitutionTest) and selective attention (d2 Test of Attention). The results revealed that exercisingat low to moderate intensity does not have an effect on the cognitive parameters testedin young adolescents. Furthermore, there were no differential effects of exercise type.The results of this study are discussed in terms of the caution which should be takenwhen conducting exercise sessions in a classroom setting aimed at improving cognitive performance.

Impact of a community-based exercise programme on physical fitness in middle-aged and older patients with type 2 diabetes

Objectives: Physical fitness is related to all-cause mortality, quality of life and risk of falls in patients with type 2 diabetes. This study aimed to analyse the impact of a long-term community-based combined exercise program (aerobic + resistance + agility/balance + flexibility) developed with minimum and low-cost material resources on physical fitness in middle-aged and older patients with type 2 diabetes. Methods: This was a non-experimental pre-post evaluation study. Participants (N = 43; 62.92 ± 5.92 years old) were engaged in a community-based supervised exercise programme (consisting of combined aerobic, resistance, agility/balance and flexibility exercises; three sessions per week; 70 min per session) of 9 months' duration. Aerobic fitness (6-Minute Walk Test), muscle strength (30-Second Chair Stand Test), agility/balance (Timed Up and Go Test) and flexibility (Chair Sit and Reach Test) were assessed before (baseline) and after the exercise intervention. Results: Significant improvements in the performance of the 6-Minute Walk Test (Δ = 8.20%, p < 0.001), 30-Second Chair Stand Test (Δ = 28.84%, p < 0.001), Timed Up and Go Test (Δ = 14.31%, p < 0.001), and Chair Sit and Reach Test (Δ = 102.90%, p < 0.001) were identified between baseline and end-exercise intervention time points. Conclusions: A long-term community-based combined exercise programme, developed with low-cost exercise strategies, produced significant benefits in physical fitness in middle-aged and older patients with type 2 diabetes. This supervised group exercise programme significantly improved aerobic fitness, muscle strength, agility/balance and flexibility, assessed with field tests in community settings.

Effects of physical exercise training in DNA damage and repair activity in humans with different genetic polymorphisms ofhOGG1(Ser326Cys)

The main purpose of this pilot study was to investigate the possible influence of genetic polymorphisms of the hOGG1 (Ser326Cys) gene in DNA damage and repair activity by 8-oxoguanine DNA glycosylase 1 (OGG1 enzyme) in response to 16 weeks of combined physical exercise training. Thirty-two healthy Caucasian men (40-74 years old) were enrolled in this study. All the subjects were submitted to a training of 16 weeks of combined physical exercise. The subjects with Ser/Ser genotype were considered as wild-type group (WTG), and Ser/Cys and Cys/Cys genotype were analysed together as mutant group (MG). We used comet assay in conjunction with formamidopyrimidine DNA glycoslyase (FPG) to analyse both strand breaks and FPG-sensitive sites. DNA repair activity were also analysed with the comet assay technique. Our results showed no differences between DNA damage (both strand breaks and FPG-sensitive sites) and repair activity (OGG1) between genotype groups (in the pre-training condition). Regarding the possible influence of genotype in the response to 16 weeks of physical exercise training, the results revealed a decrease in DNA strand breaks in both groups, a decrease in FPG-sensitive sites and an increase in total antioxidant capacity in the WTG, but no changes were found in MG. No significant changes in DNA repair activity was observed in both genotype groups with physical exercise training. This preliminary study suggests the possibility of different responses in DNA damage to the physical exercise training, considering the hOGG1 Ser326Cys polymorphism.

Home based exercise programme for knee pain and knee osteoarthritis: randomised controlled trial

Objectives To determine whether a home based exercise programme can improve outcomes in patients with knee pain. Design Pragmatic, factorial randomised controlled trial of two years' duration. Setting Two general practices in Nottingham. Participants 786 men and women aged >45 years with self reported knee pain. Interventions Participants were randomised to four groups to receive exercise therapy, monthly telephone contact, exercise therapy plus telephone contact, or no intervention. Patients in the no intervention and combined exercise and telephone groups were randomised to receive or not receive a placebo health food tablet. Main outcome measures Primary outcome was self reported score for knee pain on the Western Ontario and McMaster universities (WOMAC) osteoarthritis index at two years. Secondary outcomes included knee specific physical function and stiffness (scored on WOMAC index), general physical function (scored on SF­36 questionnaire), psychological outlook (scored on hospital anxiety and depression scale), and isometric muscle strength. Results 600 (76.3%) participants completed the study. At 24 months, highly significant reductions in knee pain were apparent for the pooled exercise groups compared with the non­exercise groups (mean difference –0.82, 95% confidence interval –1.3 to –0.3). Similar improvements were observed at 6, 12, and 18 months. Regular telephone contact alone did not reduce pain. The reduction in pain was greater the closer patients adhered to the exercise plan. Conclusions A simple home based exercise programme can significantly reduce knee pain. The lack of improvement in patients who received only telephone contact suggests that improvements are not just due to psychosocial effects because of contact with the therapist.

Effects of roller massager on muscle performance, morphology, and oxygenation after exercise-induced muscle damage

This study determined roller massager (RM) effectiveness on ankle plantar flexors’ recovery after exercise-induced muscle damage (EIMD) stimulus. Two experiments were conducted. The first experiment (n=10) examined functional [i.e., ankle plantar flexion maximal voluntary isometric contraction (MVIC) and submaximal (30% of MVIC) sustained force; ankle dorsiflexion maximal range of motion and resistance to stretch; and pain pressure threshold] and morphological [medial gastrocnemius (MG) cross sectional area, thickness, fascicle length, and fascicle angle] variables, before and immediately, 1h, 24h, 48h, and 72 after EIMD. In the second experiment (n=10), changes in MG deoxyhemoglobin concentration kinetics (velocity and amplitude) during a submaximal sustained force test were observed before and 48h after EIMD. Participants performed both experiments twice, with and without (NRM) the application of a RM (6 × 45 seconds with 20 seconds rest between sets). RM intervention did not alter plantar flexors’ strength and flexibility impairment after EIMD, as well the MG morphology and oxygenation kinetics (p>0.05). On the other hand, a strong tendency for an acute (within 1 hour) change of ipsilateral (post-effects: RM=+19%, NRM=-5%, p=0.032) and contralateral (p=0.095) MG pain pressure threshold was observed. In conclusion, the present results suggest that a roller massager has no effect on muscular performance, morphology, and oxygenation recovery after EIMD, except for muscle pain pressure threshold (i.e., a soreness). Thus, RM may have potential application in recovery for people with increased muscle soreness, if performed immediately before a physical task.

Anti-inflammatory effect of exercise training in subjects with type 2 diabetes and the metabolic syndrome is dependent on exercise modalities and independent of weight loss

We investigated the effect of different exercise modalities on high sensitivity-C reactive protein (hs-CRP) and other inflammatory markers in patients with type 2 diabetes and the metabolic syndrome. Eighty-two patients were randomized into 4 groups: sedentary control (A); receiving counseling to perform low-intensity physical activity (B); performing prescribed and supervised high-intensity aerobic (C) or aerobic + resistance (D) exercise (with the same caloric expenditure) for 12 months. Evaluation of leisure-time physical activity and assessment of physical fitness, cardiovascular risk factors and inflammatory biomarkers was performed at baseline and every 3 months. Volume of physical activity increased and HbA1c decreased in Groups B–D. VO2max, HOMA-IR index, HDL-cholesterol, waist circumference and albuminuria improved in Groups C and D, whereas strength and flexibility improved only in Group D. Levels of hs-CRP decreased in all three exercising groups, but the reduction was significant only in Groups C and D, and particularly in Group D. Changes in VO2max and the exercise modalities were strong predictors of hs-CRP reduction, independent of body weight. Leptin, resistin and interleukin-6 decreased, whereas adiponectin increased in Groups C and D. Interleukin-1β, tumor necrosis factor-α and interferon-γ decreased, whereas anti-inflammatory interleukin-4 and 10 increased only in Group D. In conclusion, physical exercise in type 2 diabetic patients with the metabolic syndrome is associated with a significant reduction of hs-CRP and other inflammatory and insulin resistance biomarkers, independent of weight loss. Long-term high-intensity (preferably mixed) training, in addition to daytime physical activity, is required to obtain a significant anti-inflammatory effect.

Exercise intervention in pediatric patients with solid tumors: The PAPEC trial

The randomized controlled trial ‘Physical Activity in Pediatric Cancer’ (PAPEC) determined the effects of an in-hospital exercise intervention combining aerobic and muscle strength training on pediatric cancer patients with solid tumors undergoing neoadjuvant chemotherapy. Methods. Participants were allocated to an exercise (n=24, 17 boys; mean±SEM age 10±1y) or control group (n=25, 18 boys; 11±1y). Training included three sessions/week for 19±2 weeks. Participants were assessed at treatment initiation, termination, and two months after end-treatment. The primary endpoint was muscle strength (as assessed by upper and lower-body five-repetition-maximum (5RM) tests). Secondary endpoints included cardiorespiratory fitness, functional capacity during daily life activities, physical activity, body mass and body mass index, and quality of life. Results. Most sessions were performed in the hospital’s gymnasium. Adherence to the program averaged 68±4% and no major adverse events or health issues were noted. A significant interaction (group*time) effect was found for all 5RM tests. Performance significantly increased after training (leg press: 40% (95% CI=15–41 kg); bench press: 24% (95% CI=6–14 kg); lateral row 25% (95%CI=6–15 kg)), whereas an opposite trend was found in controls. Two-month post values tended to be higher than baseline for leg (P=0.017) and bench press (P=0.014). In contrast, no significant interaction effect was found for any of the secondary endpoints. Conclusion. An in-hospital exercise program for pediatric cancer patients with solid tumors undergoing neoadjuvant treatment increases muscle strength despite the aggressiveness of such therapy. Key words: Cancer, exercise, muscle strength, fitness, quality of life.

Determination of metabolic equivalents during low-and high-intensity resistance exercise in healthy young subjects and patients with type 2 diabetes

The purpose of this study was to quantify the metabolic equivalents (METs) of resistance exercise in obese patients with type 2 diabetes (T2DM) and healthy young subjects and to evaluate whether there were differences between sessions executed at low- versus high-intensity resistance exercise. Twenty obese patients with T2DM (62.9±6.1 years) and 22 young subjects (22.6±1.9 years) performed two training sessions: one at vigorous intensity (80% of 1-repetition maximum (1RM)) and one at moderate intensity (60% of 1RM). Both groups carried out three strength exercises with a 2-day recovery between sessions. Oxygen consumption was continuously measured 15 min before, during and after each training session. Obese T2DM patients showed lower METs values compared with young healthy participants at the baseline phase (F= 2043.86; P<0.01), during training (F=1140.59; P<0.01) and in the post-exercise phase (F=1012.71; P<0.01). No effects were detected in the group x intensity analysis of covariance. In this study, at both light-moderate and vigorous resistance exercise intensities, the METs value that best represented both sessions was 3 METs for the obese elderly T2DM patients and 5 METs for young subjects.

Effects of dry-land strength and conditioning programs in age group swimmers

Context: Even though dry-land S&C training is a common practice in swimming, there are countless uncertainties over it effects in performance of age group swimmers. Objective: To investigate the effects of dry-land S&C programs in swimming performance of age group swimmers. Participants: A total of 21 male competitive swimmers (12.7±0.7 years) were randomly assigned to the Control Group (n=7) and experimental GR1 and GR2 (n=7 for each group). Intervention: Control group performed a 10-week training period of swim training alone, GR1 followed a 6-week dry-land S&C program based on sets/repetitions plus a 4-week swim training program alone and GR2 followed a 6-week dry-land S&C program focused on explosiveness, plus a 4-week program of swim training alone. Results: For the dry-land tests a time effect was observed between week 0 and week 6 for vertical jump (p<0.01) in both experimental groups, and for the GR2 ball throwing (p<0.01), with moderate-strong effect sizes. The time*group analyses showed that for performance in 50 m, differences were significant, with the GR2 presenting higher improvements than their counterparts (F=4.156; ƿ=0.007; η2=0.316) at week 10. Conclusions: The results suggest that 6 weeks of a complementary dry-land S&C training may lead to improvements in dry-land strength. Furthermore, a 4-week adaptation period was mandatory to achieve beneficial transfer for aquatic performance. Additional benefits may occur if coaches plan the dry-land S&C training focusing on explosiveness.