The effect of short-term aerobic training on coagulation and fibrinolytic factors in sedentary healthy postmenopausal women

Objective

The purpose of this study was to assess the effect of short-term aerobic training on the fibrinolytic and coagulative factors in postmenopausal women.

Study design

Twenty volunteer sedentary healthy postmenopausal women (48–53 years), who entered the menopause naturally, were divided randomly into two groups: training (n = 10) and control (n = 10).

Methods and main outcome measures

Training consisted of 10 sessions of submaximal aerobic cycling, 35 min for each session (5 min warm-up, 25 min aerobic training with 70% HRmax, 5 min active and 15 min passive recovery), 3 times a week. Coagulation and fibrinolytic factors were assessed both before and after aerobic program in both groups.

Results

Fibrinogen, von Willbrand factor (vWF-Ag) antigen, plasminogen activator inhibitor-1 activity (PAI-1:Ac) and antigen (PAI-1:Ag) showed significant reduction after 10 sessions in the training group (P < 0.05). Also after training, prothrombin time (PT), partial thromboplastin time (PTT), tissue plasminogen activator activity (tPA:Ac) and antigen (tPA:Ag) increased (P < 0.05).

Conclusion

It was concluded that fibrinolytic activity on postmenopausal women could be improved by a 3-week regular submaximal training program. These changes on the hemostatic factors suggest that short-term aerobic training may prevent the decline in fibrinolytic function observed in sedentary postmenopausal women.     

Alterations in coagulatory and fibrinolytic systems following an ultra-marathon

Purpose

The aim of this study was to examine coagulatory and fibrinolytic responses to the Western States Endurance Run (WSER, June 23 to 24, 2012). The WSER is a 161-km (100 mile) trail foot race through the Sierra Nevada Mountains that involves 6,030 m of climb and 7,001 m of descent.

Methods

We examined 12 men and 4 women [mean (95 % CI), age 44.6 years (38.7–50.6)] who completed the race (24.64 h; range 16.89–29.46). Blood samples were collected the morning before the race, immediately post-race, and 1 (D1) and 2 (D2) days post-race (corresponding to 51–54 h and 75–78 h from the start of the race, respectively). Hypercoagulable state was characterized by prothrombin fragment 1+2 (PTF 1+2) and thrombin–antithrombin complex (TAT). Fibrinolytic state was assessed by plasminogen activator inhibitor antigen (PAI-1 Ag), tissue plasminogen activator antigen (tPA Ag), and d-Dimer. Muscle damage was assessed by serum creatine kinase (CK) and myoglobin concentrations.

Results

Significant (P ≤ 0.05) increases were observed immediately post-race for thrombin generation markers, PTF 1+2 (3.9-fold) and TAT (2.4-fold); markers of fibrinolysis, tPA Ag (4.0-fold), PAI-1 Ag (4.5-fold), and d-Dimer (2.2-fold); and muscle damage markers, CK (154-fold) and myoglobin (114-fold). Most markers continued to be elevated at D1, as seen by PTF 1+2, TAT (1.5- and 1.3-fold increase at D1), and d-Dimer (2.5- and 2.1-fold increase at D1 and D2, respectively). Additionally, PTF 1+2:tPA and TAT:tPA ratios, which assessed balance between coagulation and fibrinolysis, were slightly, but significantly increased at D1 (69 and 36 %) and D2 (19 and 31 %). CK and myoglobin also remained elevated at D1 (54- and 7-fold) and D2 (25- and 2-fold) time points.

Conclusion

The WSER produced extensive muscle damage and activated the coagulation and fibrinolytic systems. Since we observed a slight imbalance response between the two systems, a limited potential for thrombotic episodes is apparent in these highly trained athletes.     

Exercise volume and intensity: a dose–response relationship with health benefits

Introduction

The health benefits of exercise are well established. However, the relationship between exercise volume and intensity and health benefits remains unclear, particularly the benefits of low-volume and intensity exercise.

Purpose

The primary purpose of this investigation was, therefore, to examine the dose–response relationship between exercise volume and intensity with derived health benefits including volumes and intensity of activity well below international recommendations.

Methods

Generally healthy, active participants (n = 72; age = 44 ± 13 years) were assigned randomly to control (n = 10) or one of five 13-week exercise programs: (1) 10-min brisk walking 1×/week (n = 10), (2) 10-min brisk walking 3×/week (n = 10), (3) 30-min brisk walking 3×/week (n = 18), (4) 60-min brisk walking 3×/week (n = 10), and (5) 30-min running 3×/week (n = 14), in addition to their regular physical activity. Health measures evaluated pre- and post-training including blood pressure, body composition, fasting lipids and glucose, and maximal aerobic power (VO₂max).

Results

Health improvements were observed among programs at least 30 min in duration, including body composition and VO₂max: 30-min walking 28.8–34.5 mL kg^?1 min^?1, 60-min walking 25.1–28.9 mL kg^?1 min^?1, and 30-min running 32.4–36.4 mL kg^?1 min^?1. The greater intensity running program also demonstrated improvements in triglycerides.

Conclusion

In healthy active individuals, a physical activity program of at least 30 min in duration for three sessions/per week is associated with consistent improvements in health status.     

The influence of aerobic fitness on the recovery of peak power output

Purpose

The aims of this study were to evaluate the recovery kinetics of peak power output (PPO) following a maximal sprint, and to evaluate the influence of aerobic fitness on that recovery process.

Methods

On separate occasions, 16 well-trained men (age: 21 ± 3 years; height: 1.84 ± 0.05 m; and body mass: 78.8 ± 7.8 kg) performed a 30 s maximal sprint on a cycle ergometer, followed by a predetermined stationary rest period (5, 10, 20, 40, 80, and 160 s) and a subsequent 5 s sprint to determine PPO recovery kinetics. On another occasion, \({\dot V}{{\rm O}_{2}}\) was monitored during recovery from a 30 s sprint to provide a comparison with the recovery of PPO. Finally, subjects completed a \({\dot V}{{\rm O}_{2{\rm max}}}\) test to evaluate the influence of aerobic fitness on the recovery of PPO.

Results

Despite following similar time courses (F = 0.36, p = 0.558), and being well described by double-exponential models, the kinetic parameters of PPO and \({\dot V}{{\rm O}_{2}}\) in recovery were significantly different (p < 0.05). There was no significant relationship (r = 0.15; p = 0.578) between \({\dot V}{\rm O}_{2{\rm max}}\) and the time to achieve 50 % recovery of PPO. Moreover, there was no difference (p = 0.61) between the recovery kinetics of participants classified according to their \({\dot V}{\rm O}_{2{\rm max}}\) (59.4 ± 1.3 vs 48.5 ± 2.2 ml·kg^?1·min^?1).

Conclusion

Despite similar overall recovery kinetics, \({\dot V}{{\rm O}_{2}}\) and PPO show differences in key model parameters. Moreover, the recovery of PPO does not appear to be affected by aerobic fitness.     

Short-term high-intensity interval and continuous moderate-intensity training improve maximal aerobic power and diastolic filling during exercise

Purpose

This study examined the effects of short-term high-intensity interval training (HIT) and continuous moderate-intensity training (CMT) on cardiac function in young, healthy men.

Methods

Sixteen previously untrained men (mean age of 25.1 ± 4.1 years) were randomly assigned to HIT and CMT (n = 8 each) and assessed before and after six sessions over a 12-day training period. HIT consisted of 8–12 intervals of cycling for 60 s at 95–100 % of pre-training maximal aerobic power ( $\dot{V}$ O_2max), interspersed by 75 s of cycling at 10 % $\dot{V}$ O_2max. CMT involved 90–120 min of cycling at 65 % pre-training $\dot{V}$ O_2max. Left ventricular (LV) function was determined at rest and during submaximal exercise (heart rate ~105 bpm) using two-dimensional and Doppler echocardiography.

Results

Training resulted in increased calculated plasma volume (PV) in both groups, accompanied by improved $\dot{V}$ O_2max in HIT (HIT: from 39.5 ± 7.1 to 43.9 ± 5.5 mL kg^?1 min^?1; CMT: from 39.9 ± 5.9 to 41.7 ± 5.3 mL kg^?1 min^?1; P < 0.001). Resting LV function was not altered. However, increased exercise stroke volume (P = 0.02) and cardiac output (P = 0.02) were observed, secondary to increases in end-diastolic volume (P < 0.001). Numerous Doppler and speckle tracking indices of diastolic function were similarly enhanced during exercise in both training groups and were related to changes in PV.

Conclusion

Short-term HIT and CMT elicit rapid improvements in $\dot{V}$ O_2max and LV filling without global changes in cardiac performance at rest.     

Small-sided games training reduces CRP,IL-6 and leptin in sedentary,middle-aged men

Purpose

Long-term physical activity is reported to improve chronic systemic inflammation, which provides protection against the ensuing development of chronic disease. Accordingly, the present study assessed changes in pro- and anti-inflammatory cytokines, aerobic capacity and body composition following 8 weeks of either small-sided games (SSG) or cycling (CYC) training compared to a sedentary control (CON) condition.

Methods

Thirty-three middle-aged, sedentary men were randomized into CYC (n = 11), SSG (n = 11), or CON (n = 11) conditions. The CYC and SSG conditions trained 3 days/week for 8 weeks, whilst CON maintained habitual activity and dietary patterns. Pre- and post-intervention testing included a dual-energy X-ray absorptiometry scan, sub-maximal (80 % maximal heart rate) aerobic capacity (VO₂) and fasting venous blood. Venous blood measures for pro-inflammatory markers included C-reactive protein (CRP), interleukin (IL)-6, IL-1β, tumor necrosis factor-α, and leptin; anti-inflammatory markers included IL-10, IL-1 receptor agonist, and adiponectin.

Results

Both CYC and SSG increased submaximal power output and VO₂ (P < 0.05), decreased total body fat-mass (TB-FM; P < 0.05), and CRP (SSG, ?0.45 ± 0.42 mg L^?1; P = 0.008; CYC, ?0.44 ± 0.59 mg L^?1; P = 0.02). Only SSG increased total body fat-free mass (TB-FFM; +1.1 ± 1.2 kg; P = 0.001) and decreased concentration of plasma IL-6 (?0.69 ± 0.62 pg mL^?1; P = 0.002) and leptin (?2,212 ± 2,531 ng mL^?1; P = 0.014).

Conclusion

Cycling and SSG training were both effective at improving CRP, VO₂ and TB-FM. Furthermore, SSG training has also shown to be an effective training approach in reducing IL-6 and leptin and increasing muscle mass within sedentary, middle-aged men.     

Reactive oxygen and nitrogen species in sepsis-induced hepatic microvascular dysfunction

Objective and design

Hepatic microvascular dysfunction is a critical event in the development of liver failure during sepsis. Activated blood cells and reactive oxygen and nitrogen species (RONS) have been implicated in the pathogenesis of sepsis.

Methods

Intravital-videomicroscopy was used to determine whether RONS contribute to the recruitment of leukocytes/platelets in the hepatic microvasculature during sepsis. Six hours following cecal-ligation and puncture (CLP), disturbances of the hepatic microvasculature were assessed in WT-mice (C57Bl/6 J; n = 8), in mice lacking gp91^phox(n = 5), overexpressing superoxide-dismutase (SOD, n = 8), in WT-mice treated with a NOS-inhibitor (l-NAME, n = 5), lacking nNOS, eNOS or iNOS (n = 5 each), treated with the NO-donor DetaNO (n = 5), in WT-mice treated with gadolinium-chloride (GdCl₂, n = 5) and compared to a group of WT-mice following a sham operation (n = 8). Six hours post-CLP, the adhesion of leukocytes and platelets in terminal hepatic venules (THV) and sinusoids was quantified.

Results

In WT-mice, CLP elicited increases in the number of adherent leukocytes and platelets. Similar responses to CLP were noted in mice overexpressing SOD or lacking either eNOS or gp91^phox. The blood-cell recruitment was significantly blunted in septic iNOS-knockout mice and this response was reversed by pre-treatment with DetaNO.

Conclusion

These findings suggest that iNOS-derived NO is a determinant of the pro-inflammatory phenotype assumed by the hepatic microvasculature during sepsis.     

Effects of high vs. moderate exercise intensity during interval training on lipids and adiponectin levels in obese young females

Purpose

We investigate the effects of 12-week interval training of moderate- or high-intensity exercise on blood lipids and plasma levels of adiponectin.

Methods

Thirty-four obese adolescent females [age = 15.9 ± 0.3 years; BMI and BMI-Z-score = 30.8 ± 1.6 kg/m² and 3 ± 0.3, respectively], were randomized to high-intensity interval training (HIIT, n = 11), moderate-intensity interval training (MIIT, n = 11), or a control group (CG, n = 12). Maximal oxygen uptake ( $\mathop V\limits^{.} {\text{O}}_{{2{\text{peak}}}}$ V . O 2 peak ), maximal aerobic speed (MAS), plasma lipids and adiponectin levels were measured in all subjects before and after training.

Results

Following the training program, in both training groups, body mass, BMI-Z-score, and percentage body fat (% BF) decreased, while $\mathop V\limits^{.} {\text{O}}_{{2{\text{peak}}}}$ V . O 2 peak and MAS increased. Low-density lipoprotein cholesterol, high-density lipoprotein cholesterol, and adiponectin levels were positively altered (?12.6 and ?7.4 %; 6.3 and 8.0 %; 35.8 and 16.2 %; high to moderate training program, respectively). Waist circumference, triglyceride and total cholesterol decreased only in HIIT group (?3.5; ?5.3 and ?7.0 %, respectively, in all P < 0.05). Significant decrease in the usual index of insulin resistance (HOMA-IR) occurred in HIIT and MIIT groups (?29.2 ± 5.3 and ?18.4 ± 8.6 %, respectively; P < 0.01).

Conclusion

The results show that HIIT positively changes blood lipids and adiponectin variables in obese adolescent girls, resulting in improved insulin sensitivity, as attested by a lower HOMA-IR, and achieving better results compared to moderate-intensity exercise.     

Effects of beta-alanine supplementation and interval training on physiological determinants of severe exercise performance

Introduction

We aimed to manipulate physiological determinants of severe exercise performance. We hypothesized that (1) beta-alanine supplementation would increase intramuscular carnosine and buffering capacity and dampen acidosis during severe cycling, (2) that high-intensity interval training (HIT) would enhance aerobic energy contribution during severe cycling, and (3) that HIT preceded by beta-alanine supplementation would have greater benefits.

Methods

Sixteen active men performed incremental cycling tests and 90-s severe (110 % peak power) cycling tests at three time points: before and after oral supplementation with either beta-alanine or placebo, and after an 11-days HIT block (9 sessions, 4 × 4 min), which followed supplementation. Carnosine was assessed via MR spectroscopy. Energy contribution during 90-s severe cycling was estimated from the O₂ deficit. Biopsies from m. vastus lateralis were taken before and after the test.

Results

Beta-alanine increased leg muscle carnosine (32 ± 13 %, d = 3.1). Buffering capacity and incremental cycling were unaffected, but during 90-s severe cycling, beta-alanine increased aerobic energy contribution (1.4 ± 1.3 %, d = 0.5), concurrent with reduced O₂ deficit (?5.0 ± 5.0 %, d = 0.6) and muscle lactate accumulation (?23 ± 30 %, d = 0.9), while having no effect on pH. Beta-alanine also enhanced motivation and perceived state during the HIT block. There were no between-group differences in adaptations to the training block, namely increased buffering capacity (+7.9 ± 11.9 %, p = 0.04, d = 0.6, n = 14) and glycogen storage (+30 ± 47 %, p = 0.04, d = 0.5, n = 16).

Conclusions

Beta-alanine did not affect buffering considerably, but has beneficial effects on severe exercise metabolism as well as psychological parameters during intense training phases.     

The relationship between body mass index, aerobic performance and asthma in a pre-pubertal, population-level cohort

Purpose

To assess the relationship between asthma, body mass index (BMI) and aerobic performance, as indicated by a shuttle test.

Methods

20,577 participants (10,413 boys) from the SportsLinx serial cross-sectional study participated. Parental reports of asthma status and home postcode data were gathered from consent forms. Stature, sitting stature and body mass were measured and BMI, somatic maturity and indices of multiple deprivation scores (IMD) were derived. Performance on the 20 m multi-stage shuttle runs test (20mSRT) was used to estimate cardiorespiratory fitness (CRF).

Results

Asthma [F (1, 17,015) = 82.26, P < 0.01] and gender [F (1, 17,015) = 678.491, P < 0.001] significantly influenced 20mSRT. The addition of BMI, maturity and IMD to the model did not alter these significant effects. There was a significant interaction between 20mSRT and BMI [F (1, 16,723) = 132.80, P < 0.01], with a significant decrease in 20mSRT from the 50th BMI percentile upwards [t (16,699) = 36.88, P < 0.01]. Binary logistic regression revealed gender and 20mSRT to be significant predictors of asthma occurrence; BMI SDS just reached significance whilst maturity and IMD were not significant contributors to the model.

Conclusions

This study demonstrates the negative influences of low CRF and high BMI on the risk of asthma occurrence in pre-pubertal children. Furthermore, it highlights the significant influence of BMI on CRF, revealing these effects to be manifest considerably below those BMI percentiles conventionally associated with being overweight or obese.     

Moderate and heavy metabolic stress interval training improve arterial stiffness and heart rate dynamics in humans

Traditional continuous aerobic exercise training attenuates age-related increases of arterial stiffness, however, training studies have not determined whether metabolic stress impacts these favourable effects. Twenty untrained healthy participants (n = 11 heavy metabolic stress interval training, n = 9 moderate metabolic stress interval training) completed 6 weeks of moderate or heavy intensity interval training matched for total work and exercise duration. Carotid artery stiffness, blood pressure contour analysis, and linear and non-linear heart rate variability were assessed before and following training. Overall, carotid arterial stiffness was reduced (p < 0.01), but metabolic stress-specific alterations were not apparent. There was a trend for increased absolute high-frequency (HF) power (p = 0.10) whereas both absolute low-frequency (LF) power (p = 0.05) and overall power (p = 0.02) were increased to a similar degree following both training programmes. Non-linear heart rate dynamics such as detrended fluctuation analysis $({| {1 - \alpha_{1} }|})$ also improved (p > 0.05). This study demonstrates the effectiveness of interval training at improving arterial stiffness and autonomic function, however, the metabolic stress was not a mediator of this effect. In addition, these changes were also independent of improvements in aerobic capacity, which were only induced by training that involved a high metabolic stress.     

Low-volume,high-intensity,aerobic interval exercise for sedentary adults: \dot{V}O2max,cardiac mass,and heart rate recovery

Purpose

The aim of this study was to compare the effects of low-volume, high-intensity aerobic interval training (HAIT) on maximal oxygen consumption ( \(\dot{V}\) O_2max), left ventricular (LV) mass, and heart rate recovery (HRR) with high-volume, moderate-intensity continuous aerobic training (CAT) in sedentary adults.

Methods

Twenty-four healthy but sedentary male adults (aged 29.2 ± 7.2 years) participated in an 8-week, 3-day a week, supervised exercise intervention. They were randomly assigned to either HAIT (18 min, 180 kcal per exercise session) or CAT (45 min, 360 kcal). \(\dot{V}\) O_2max, LV mass (3T-MRI), and HRR at 1 min (HRR-1) and 2 min (HRR-2) after maximal exercise were measured pre- and post-intervention.

Results

Changes in \(\dot{V}\) O_2max during the 8-week intervention were significant (P < 0.01) in both groups (HAIT, 8.7 ± 3.2 ml kg^?1 min^?1, 22.4 ± 8.9 %; CAT, 5.5 ± 2.8 ml kg^?1 min^?1, 14.7 ± 9.5 %), while the \(\dot{V}\) O_2max improvement in HAIT was greater (P = 0.02) than in CAT. LV mass in HAIT increased (5.1 ± 8.4 g, 5.7 ± 9.1 %, P = 0.05), but not in CAT (0.9 ± 7.8 g, 1.1 ± 8.4 %, P = 0.71). While changes in HRR-1 were not significant in either group, change in HRR-2 for HAIT (9.5 ± 6.4 bpm, 19.0 ± 16.0 %, P < 0.01) was greater (P = 0.03) than for CAT (1.6 ± 10.9 bpm, 3.9 ± 16.2 %, P = 0.42).

Conclusions

This study suggests that HAIT has potential as a time-efficient training mode to improve cardiorespiratory capacity and autonomic nervous system function in sedentary adults.     

Associations of objectively measured sedentary behavior,light activity,and markers of cardiometabolic health in young women

Purpose

To investigate the associations among objectively measured sedentary behavior, light physical activity, and markers of cardiometabolic health in young women.

Methods

Cardiovascular disease risk factors, homeostasis model assessment for insulin resistance (HOMA-IR), lipid accumulation product, and inflammatory markers were measured in 50 young, adult women. Accelerometers were worn over 7 days to assess sedentary time (<150 counts min^?1), light physical activity (150–2,689 counts min^?1), and moderate-to-vigorous physical activity (MVPA; ≥2,690 counts min^?1). Multivariate regression examined independent associations of sedentary behavior and light physical activity with cardiometabolic health. Covariates included MVPA, cardiorespiratory fitness (VO_2peak) and body mass, and body composition.

Results

Sedentary behavior was associated with triglycerides (p = 0.03) and lipid accumulation product (p = 0.02) independent of MVPA. These associations were attenuated by VO_2peak and body mass or body composition (p ≥ 0.05). Light physical activity was independently associated with triglycerides and lipid accumulation product after adjustment for all covariates (p < 0.05). The association between light physical activity and HOMA-IR was independent of MVPA (p = 0.02) but was attenuated by VO_2peak and body mass or body composition (p > 0.05).

Conclusions

Sedentary behavior and light physical activity were independently associated with markers of cardiometabolic health in young, adult women. Our data suggest that VO_2peak and body composition may be important mediators of these associations. Decreasing sedentary behavior and increasing light physical activity may be important for maintaining cardiometabolic health in young, adult women.     

Three months of moderate-intensity exercise reduced plasma 3-nitrotyrosine in rheumatoid arthritis patients

Purpose

Rheumatoid arthritis (RA) patients display high levels of oxidative stress. Transient exercise-induced increases in oxidative stress are thought to be adaptive in healthy populations. This study investigated the effect of exercise on markers of oxidative stress in RA, following acute exercise and a period of exercise training.

Methods

Acute exercise study: RA patients (N = 12, age: 56 ± 11) undertook a bout of exercise (30–40 min, 70 % VO_2MAX), and blood samples were taken before and after exercise to assess markers of oxidative stress. Training study: RA patients (N = 19, age: 56 ± 10) were randomised into either a control or exercise group, who undertook 3 exercise sessions per week (30–40 min @70 % VO_2MAX) for 3 months. Plasma markers of oxidative stress (protein carbonyls (PC), lipid hydroperoxides (LOOH), 3-nitrotyrosine (3-NT), total antioxidant capacity (TAC) and catalase (CAT) activity), inflammation (interleukin-8 (IL-8) and C-reactive protein (CRP)) and nitric oxide metabolites (NOx) were assessed before and after training.

Results

Acute exercise study: Protein carbonyls (PC) (+18 %) and NOx (+27 %) were significantly increased following exercise. Training study: 3-nitrotyrosine (3-NT) decreased (2.18 ± 1.78 to 1.10 ± 0.93 μM) in the exercise group only, alongside increases in aerobic fitness (24.45 ± 4.98 to 27.10 ± 4.51 ml/kg/min^?1) and reductions in disease activity score (DAS: 3.47 ± 1.17 to 2.88 ± 0.76). PC, LOOH, TAC, IL-8, CRP and NOx concentrations, and CAT activity were unchanged in both groups.

Conclusions

Aerobic exercise training did not increase markers of oxidative stress in RA patients. 3-Nitrotyrosine and disease activity were decreased following exercise training.     

The Association Between Weight Status,Weight History,Physical Activity,and Cognitive Task Performance

Purpose

Physical activity has been shown to attenuate the association between overweight/obesity and deleterious cardiovascular health-related outcomes, with emerging work also taking the duration of overweight/obesity into consideration. No previous work, however, has explored the interrelationships between physical activity, obesity, and obesity duration in the context of cognitive task performance, which was the purpose of this study.

Method

Data from the 1999–2002 National Health and Nutrition Examination Survey were used (N = 2322 adults 60–85 yrs). Physical activity was assessed via self-report, with body mass index (BMI) directly measured. Participants were classified into one of eight mutually exclusive groups: (0) normal weight now and 10 years ago and active now (n = 195), (1) normal weight and 10 years ago and inactive now (n = 265), (2) normal weight now but not 10 years ago and active now (n = 46), (3) normal weight now but not 10 years ago and inactive now (n = 123), (4) overweight/obese now but not 10 years ago and active now (n = 117), (5) overweight/obese now but not 10 years ago and inactive now (n = 168), (6) overweight/obese now and 10 years ago and active now (n = 435), and (7) overweight/obese now and 10 years ago and inactive now (n = 973). The digit symbol substitution test (DSST) was employed to assess cognitive task performance.

Results

After adjustments, only individuals who were inactive (groups 1, 3, 5, and 7) had significantly lower cognitive task performance.

Conclusion

Being inactive, regardless of weight classification and duration of overweight/obesity, was inversely associated with cognitive task performance in this national sample of older adults.

     

Maximal strength,power, and aerobic endurance adaptations to concurrent strength and sprint interval training

Purpose

This study was designed to examine whether concurrent sprint interval and strength training (CT) would result in compromised strength development when compared to strength training (ST) alone. In addition, maximal oxygen consumption (VO₂max) and time to exhaustion (TTE) were measured to determine if sprint interval training (SIT) would augment aerobic performance.

Methods

Fourteen recreationally active men completed the study. ST (n = 7) was performed 2 days/week and CT (n = 7) was performed 4 days/week for 12 weeks. CT was separated by 24 h to reduce the influence of acute fatigue. Body composition was analyzed pre- and post-intervention. Anaerobic power, one-repetition maximum (1RM) lower- and upper-body strength, VO₂max and TTE were analyzed pre-, mid-, and post-training. Training intensity for ST was set at 85 % 1RM and SIT trained using a modified Wingate protocol, adjusted to 20 s.

Results

Upper- and lower-body strength improved significantly after training (p < 0.001) with no difference between the groups (p > 0.05). VO₂max increased 40.9 ± 8.4 to 42.3 ± 7.1 ml/kg/min (p < 0.05) for CT, whereas ST remained unchanged. A significant difference in VO₂max (p < 0.05) was observed between groups post-intervention (CT: 42.3 ± 7.1 vs. ST: 36.0 ± 3.0 ml/kg/min). A main effect for time and group was observed in TTE (p < 0.05). A significant main effect for time was observed in average power (p < 0.05).

Conclusion

Preliminary findings suggest that performing concurrent sprint interval and strength training does not attenuate the strength response when compared to ST alone, while also improves aerobic performance measures, such as VO₂max at the same time.     

“Live High–Train High” increases hemoglobin mass in Olympic swimmers

Purpose

This study tested whether 3–4 weeks of classical “Live High–Train High” (LHTH) altitude training increases swim-specific VO_2max through increased hemoglobin mass (Hb_mass).

Methods

Ten swimmers lived and trained for more than 3 weeks between 2,130 and 3,094 m of altitude, and a control group of ten swimmers followed the same training at sea-level (SL). Body composition was examined using dual X-ray absorptiometry. Hb_mass was determined by carbon monoxide rebreathing. Swimming VO_2peak was determined and swimming trials of 4 × 50, 200 and 3,000 m were performed before and after the intervention.

Results

Hb_mass (n = 10) was increased (P < 0.05)after altitude training by 6.2 ± 3.9 % in the LHTH group, whereas no changes were apparent in the SL group (n = 10). Swimming VO_2peak was similar before and after training camps in both groups (LHTH: n = 7, SL: n = 6). Performance of 4 × 50 m at race pace was improved to a similar degree in both groups (LHTH: n = 10, SL: n = 10). Maximal speed reached in an incremental swimming step test (P = 0.051), and time to complete 3,000 m tended (P = 0.09) to be more improved after LHTH (n = 10) than SL training (n = 10).

Conclusion

In conclusion, 3–4 weeks of classical LHTH is sufficient to increase Hb_mass but exerts no effect on swimming-specific VO_2peak. LHTH may improve performance more than SL training.     

Odd-impact loading results in increased cortical area and moments of inertia in collegiate athletes

Purpose

The purpose of this study was to investigate tibial changes in volumetric bone mineral density and geometry that take place in athletes from pre- to post-season.

Methods

Female college athletes (n = 36) and ten controls recruited from the student population were included in the study. Participants had their left tibia scanned by pQCT at 4, 20, and 66 % of the overall length from the distal end before and after their competitive seasons. Subjects were divided into four groups: non-athlete (controls, n = 10), moderate-impact (cross-country runners, n = 13), high-impact (volleyball and basketball, n = 11), and odd-impact (soccer, n = 12).

Results

Anterior–posterior and medial–lateral diameter increased at the 4 % site in control subjects. In the moderate-impact group, medial–lateral moment of inertia (MOI) increased by 1.2 ± 1.8 (mean ± SD) percent at the 20 % site. In high-impact group, anterior–posterior MOI increased by 1.6 ± 2.0 percent at the 66 % site. In odd-impact group, cortical area (1.4 ± 2.3 %) and cortical thickness (1.8 ± 2.8 %) increased at the 20 % site increased, as did the polar MOI (1.8 ± 2.2 %) at the 66 % site.

Conclusions

Load-specific changes resulting in improved measures of bone strength take place in athletes during a competitive season. These changes may result in improved resistance to fractures and stress fractures.     

HIT maintains performance during the transition period and improves next season performance in well-trained cyclists

Purpose

To investigate the effects of combining low-intensity endurance training (LIT) with one high-intensity endurance training (HIT) session every 7–10 days (EXP, n = 7) vs. traditional approach focusing on LIT (TRAD, n = 6) during the transition period. The effects of different training strategies during the transition period were investigated after the transition period and at the beginning of the subsequent competition season.

Methods

Well-trained cyclists were tested after the competition season, after an 8-week transition period, and after a 16-week preparatory period, before the subsequent competition season. The only difference between groups was a larger time with HIT during the transition phase in EXP.

Results

It was very likely that EXP had a larger impact on power output at 4 mmol L^?1 [la^?] after both the transition period and after the preparatory period than TRAD [between-group change (90 % CI): 10.6 % (8.2 %) and 12.9 % (11.9 %), respectively]. It was very likely that EXP had a larger impact on mean power output in the 40-min all-out trial after the transition period than TRAD [between-group change 12.4 % (7.6 %)]. EXP was also likely to have a larger improvement in the 40-min trial performance from pre-test to after the preparatory period than TRAD [between-group change 6.0 % (6.6 %)].

Conclusion

The present findings suggest that HIT sessions should be incorporated during the transition phase to avoid reduction in fitness and performance level and thereby increase the likelihood of improved performance from the end of one season to the beginning of the subsequent season.