Acute Aerobic Exercise Induces Short-Term Reductions in Ambulatory Blood Pressure in Patients With Hypertension: A Systematic Review and Meta-Analysis

[Figure: see text].

Durability and repeatability of professional cyclists during a Grand Tour

Durability and repeatability (i.e. the ability to sustain high power output values under fatigue and to endure repeated high-intensity efforts, respectively) are emerging as cycling performance determinants. We aimed to analyze whether these markers differ between professional cyclists of two competition levels (WorldTour [WT] and Proteam [PT]) during a Grand Tour. We studied 8 WT and 7 PT cyclists who competed in "La Vuelta 2020". Durability was assessed with the mean maximal power (MMP) values attained between 5 sec-30 min after different levels of mechanical work done (0-35 kJ·kg^-1). Repeatability was assessed as the ability to repeat efforts >95% MMP. Although no differences were found for durability during the whole race (p = 0.209), a significant interaction effect was found in separate analyses by week (p = 0.011). Thus, during the first week and in the "fresh" state (0 kJ·kg^-1), WT cyclists solely attained significantly higher MMP values for 30-min efforts. However, these differences enlarged with accumulating levels of fatigue (e.g. significantly higher MMP values in WT cyclists for 30-sec, 1-min, 5-min, 20-min and 30-min efforts after 35 kJ·kg^-1). On the other hand, no between-group differences were found in repeatability for the whole race (p = 0.777) or in separate analyses by week (p = 0.808). In summary, the present results support the role of durability (but not of repeatability) as a performance indicator during professional cycling races.

Mortality Risk from Neurodegenerative Disease in Sports Associated with Repetitive Head Impacts: Preliminary Findings from a Systematic Review and Meta-Analysis

BACKGROUND

Professional athletes seem to have a lower overall mortality risk than the general population, but controversy exists about whether athletes in sports associated with repetitive head impacts have a higher risk of mortality from neurodegenerative diseases.

OBJECTIVE

We aimed to determine the risk of mortality from neurodegenerative diseases in sports associated with repeated head impacts compared with the general population or compared with athletes with no such exposure.

METHODS

We conducted a systematic review with meta-analysis, systematically searching PubMed, Web of Science, Scopus, and SPORTDiscus (since inception to 14 May 2021) for studies comparing the risk of death from neurodegenerative disease in athletes participating in contact sports in which their heads recurrently receive blows from the bodies of other participants or from a ball versus a control group or dataset representing the general population.

RESULTS

Six moderate- to high-quality retrospective studies including data from 41,699 athletes participating in contact sports (boxing, basketball, ice hockey, American Football and soccer) met all inclusion criteria to be included in the systematic review. Of these, three studies (N = 37,065 male professional soccer players) could be meta-analysed. Despite no differences in the risk of all-cause (p = 0.138), cardiovascular (p = 0.085) and cancer-related mortality (p = 0.136), soccer players presented with a significantly higher mortality risk from motor neuron disease (standard mortality rate 8.43; 95% confidence interval 3.07-23.13; p < 0.001).

CONCLUSIONS

Although more research is needed (particularly in other contact sports and with neurodegenerative disease as the cause of death), preliminary evidence suggests that participation in professional soccer might increase the risk of mortality from motor neuron disease compared with the general population. The present findings highlight the need for the design of preventive measures and for adequate neuropsychological monitoring in these athletes.

PROSPERO REGISTRATION

CRD42020195647.

Is hip morphology a risk factor for developing hip osteoarthritis? A systematic review with meta-analysis

OBJECTIVE

To appraise the highest evidence on hip morphology as a risk factor for developing hip osteoarthritis (OA).

DESIGN

We searched for studies evaluating the association between radiological hip morphology parameters and the prevalence, incidence or progression of hip OA (based on different radiographic and clinical criteria) in the MEDLINE, EMBASE, Web of Science, Scopus, Cochrane Library and PEDro databases from inception until June 2020. Prospective and cross-sectional studies were separately evaluated. Data are presented as odds ratios (OR) with 95% confidence intervals (CI).

RESULTS

We included 9 prospective and 21 cross-sectional studies in the meta-analysis, and evaluated 42,831 hips from 25,898 individuals (mean age: 59 years). Prospective studies showed that, compared with control hips, hips with cam morphology (alpha angle >60°; OR = 2.52, 95% CI: 1.83 to 3.46, P < 0.001) or hip dysplasia (lateral center-edge angle (LCEA) <25°; OR = 2.38, 95% CI: 1.84 to 3.07, P < 0.001), but not hips with pincer morphology (LCEA >39°; OR = 1.08, 95% CI: 0.57 to 2.07, P = 0.810), were more likely to develop hip OA than hips without these morphologies. Cross-sectional studies showed a greater prevalence of pincer morphology (LCEA >39°, OR = 3.71, 95% CI: 2.98 to 4.61, P < 0.001) and acetabular retroversion (crossover sign; OR = 2.65, 95% CI: 1.17 to 6.03, P = 0.020) in hips with OA than in control hips.

CONCLUSION

Cam morphology and hip dysplasia were consistently associated with the development of hip OA. Pincer morphology was associated with hip OA in cross-sectional but not in prospective studies. The heterogeneous quantification of pincer morphology on radiographs limits a clear conclusion on its association with hip OA.

Effects of Combining a Ketogenic Diet with Resistance Training on Body Composition, Strength, and Mechanical Power in Trained Individuals: A Narrative Review

Ketogenic diets (KD) have gained popularity in recent years among strength-trained individuals. The present review summarizes current evidence—with a particular focus on randomized controlled trials—on the effects of KD on body composition and muscle performance (strength and power output) in strength-trained individuals. Although long-term studies (>12 weeks) are lacking, growing evidence supports the effectiveness of an ad libitum and energy-balanced KD for reducing total body and fat mass, at least in the short term. However, no or negligible benefits on body composition have been observed when comparing hypocaloric KD with conventional diets resulting in the same energy deficit. Moreover, some studies suggest that KD might impair resistance training-induced muscle hypertrophy, sometimes with concomitant decrements in muscle performance, at least when expressed in absolute units and not relative to total body mass (e.g., one-repetition maximum). KD might therefore be a beneficial strategy for promoting fat loss, although it might not be a recommendable option to gain muscle mass and strength/power. More research is needed on the adoption of strategies for avoiding the potentially detrimental effect of KD on muscle mass and strength/power (e.g., increasing protein intake, reintroduction of carbohydrates before competition). In summary, evidence is as yet scarce to support a major beneficial effect of KD on body composition or performance in strength-trained individuals. Furthermore, the long-term effectiveness and safety of this type of diet remains to be determined.

Mortality from mental disorders and suicide in male professional American football and soccer players: A meta-analysis

OBJECTIVE

To determine the risk of mortality from mental disorders and suicide in professional sports associated with repeated head impacts.

METHODS

A systematic search was performed in PubMed, Web of Science, Scopus, and SPORTDiscus (since inception to June 8, 2021) to find studies comparing the incidence of mortality from mental disorders or suicide in former or active professional athletes of sports characterized by repeated head impacts vs athletes with no such exposure or the general non-athletic population.

RESULTS

Seven retrospective studies of moderate-to-high quality that included data from boxers and from basketball, ice hockey, soccer, and National Football League (NFL) players, respectively (total = 27 477 athletes, 100% male) met all inclusion criteria. Former male NFL players (n = 13 217) had a lower risk of mortality from mental disorders (standard mortality rate [SMR] = 0.30; 0.12-0.77; p = 0.012) and suicide (SMR = 0.54; 0.37-0.78; p < 0.001) than the general population. This finding was also corroborated in male soccer players (n = 13,065; SMR = 0.55; 0.46-0.67; p < 0.001). Male athletes participating in sports associated with repeated head impacts (n = 18,606) had also a lower risk of all-cause, cardiovascular disease (CVD), and cancer mortality (all p < 0.01) than the general population.

CONCLUSIONS

Participation of male athletes in American football or soccer at the professional level might confer a certain protective effect against mortality from mental disorders or suicide, besides its association with a lower risk of all-cause, CVD, or cancer-related mortality.

Omics sciences for systems biology in Alzheimer's disease: State-of-the-art of the evidence

Alzheimer's disease (AD) is characterized by non-linear, genetic-driven pathophysiological dynamics with high heterogeneity in biological alterations and disease spatial-temporal progression. Human in-vivo and post-mortem studies point out a failure of multi-level biological networks underlying AD pathophysiology, including proteostasis (amyloid-β and tau), synaptic homeostasis, inflammatory and immune responses, lipid and energy metabolism, oxidative stress. Therefore, a holistic, systems-level approach is needed to fully capture AD multi-faceted pathophysiology. Omics sciences - genomics, epigenomics, transcriptomics, proteomics, metabolomics, lipidomics - embedded in the systems biology (SB) theoretical and computational framework can generate explainable readouts describing the entire biological continuum of a disease. Such path in Neurology is encouraged by the promising results of omics sciences and SB approaches in Oncology, where stage-driven pathway-based therapies have been developed in line with the precision medicine paradigm. Multi-omics data integrated in SB network approaches will help detect and chart AD upstream pathomechanistic alterations and downstream molecular effects occurring in preclinical stages. Finally, integrating omics and neuroimaging data - i.e., neuroimaging-omics - will identify multi-dimensional biological signatures essential to track the clinical-biological trajectories, at the subpopulation or even individual level.

Unsupervised home-based resistance training for community-dwelling older adults: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

We aimed to summarize evidence on the safety, adherence and effectiveness of home-based resistance training (UHBRT) for improving health-related endpoints in community-dwelling older adults.

METHODS

Randomized controlled trials of UHBRT in older adults (≥60yrs) were included after a systematic search (PubMed, CINAHL, PsycInfo, SPORTDiscus, Web of Science, MEDLINE, Cochrane Central Register of Controlled Trials) until 02/19/2021. Adverse events and adherence rates were assessed as indicators of feasibility. Other endpoints included physical (muscle strength, muscle power, balance, physical performance) and mental-related measures (cognition, quality of life [QoL]) as well as other health-related variables (body composition, physical activity levels, falls).

RESULTS

21 studies (N = 4,053) were included. No major adverse events were reported, with adherence averaging 67 % (range 47-97 %). UHBRT significantly improved lower-limb muscle strength (Hedges' g = 0.33; 95 % confidence interval [CI] = 0.11-0.57), muscle power measured through the sit-to-stand test (g = 0.44; 95 %CI = 0.06-0.84), and balance (assessed with the postural sway, g = 0.32; 95 %CI = 0.16-0.49). No benefits were found for other strength indices (handgrip strength), balance (single leg stance and functional reach test), physical performance (walking speed, TUG and SPPB), QoL, nor for the risk or rate of falls (all p > 0.05, g<0.61). No meta-analysis could be performed for the remaining endpoints.

CONCLUSIONS

Although efforts are needed to increase adherence, preliminary evidence suggests that UHBRT can be safe and modestly effective for improving some measures of lower-limb muscle strength, balance, and muscle power in community-dwelling older adults. However, no benefits were found for other physical fitness measures, QoL or falls. More evidence is therefore needed to draw definite conclusions.

Ischemic Preconditioning and Muscle Force Capabilities

ABSTRACT

Valenzuela, PL, Martín-Candilejo, R, Sánchez-Martínez, G, Bouzas Marins, JC, de la Villa, P, and Sillero-Quintana, M. Ischemic preconditioning and muscle force capabilities. J Strength Cond Res 35(8): 2187-2192, 2021-This study analyzed the effects of ischemic preconditioning (IPC) on muscle force capabilities. Sixteen male subjects participated in this randomized, crossover, sham-controlled study. They were assigned to either IPC (3 × 5 minutes at 220 mm Hg in both arms with 5-minute rests) or a sham intervention (SHAM) (occlusion pressure set at 10 mm Hg). Forty minutes later, their force capabilities on the bench press exercise were assessed (load-velocity relationship with light, moderate, and heavy loads [30, 50, and 70% body mass, respectively]; 1 repetition maximum [1RM]; and number of repetitions to failure in 3 sets with 60% RM). The skin temperature (Tsk) of the pectoral and biceps muscles was analyzed as a secondary endpoint by means of infrared thermography. A significant decrease in the Tsk of the pectoral and biceps muscles was observed after the intervention (p < 0.01) and before the warm-up (p < 0.05) in IPC, but not in SHAM. However, exercise resulted in a similar Tsk increase in the pectoral muscles in both conditions (p > 0.05). No significant differences (p > 0.05 for all) were observed between conditions in the mean velocity attained with light (1.11 ± 0.11 and 1.09 ± 0.14 m·s-1, respectively), moderate (0.83 ± 0.14 and 0.83 ± 0.16 m·s-1), nor heavy loads (0.56 ± 0.17 and 0.54 ± 0.16 m·s-1), in 1RM (75.0 ± 18.9 and 73.1 ± 15.0 kg for IPC and SHAM, respectively; p = 0.181), nor in the number of repetitions performed (52 ± 13 and 54 ± 16 repetitions, p = 0.492). In summary, IPC decreased Tsk locally (biceps) and remotely (pectoral). However, it did not alter muscle force capabilities nor the Tsk response to exercise.

Effects of an Injury Prevention Program in CrossFit Athletes: A Pilot Randomized Controlled Trial

The present study aimed to assess the effects of an injury prevention program in CrossFit athletes. Thirty-two CrossFit athletes were randomized to either an intervention group (n=16), that performed mobility and stability exercises during the warm-up of all CrossFit sessions for a 10-week period or to a control group (n=16) that kept performing their usual warm-up. Incidence of injuries (primary outcome) as well as average training loads, fatigue and pain perception were registered during the study. The overall injury incidence rate was 0.04 per 1000 training hours, with no differences between groups (p>0.05). Similarly, no between-group differences were found for injury severity, nor for average training volume, intensity, training load, pain, or fatigue perception during the study (all p>0.05 with trivial-to-small effect sizes). In summary, a 10-week injury prevention program consisting of stability and mobility exercises provided no benefits on injury rates, fatigue and pain perception in recreational CrossFit athletes. Further research might corroborate the preliminary evidence reported here.

Exercise Reduces Medication for Metabolic Syndrome Management: A 5-Year Follow-up Study

PURPOSE

This study aimed to determine the effects of a 5-yr exercise intervention on metabolic syndrome (MetS) and health-related variables and medication use for MetS management.

METHODS

Participants were randomly assigned to an exercise intervention (n = 25, 54 ± 2 yr, 20% women) or control group (n = 26, 54 ± 2 yr, 38% women). The intervention lasted 4 months per year and consisted of high-intensity interval training on a cycloergometer thrice a week. Outcomes were MetS z-score and medication use score, MetS-related variables (including blood pressure, blood glucose homeostasis, and lipid profile), and cardiorespiratory fitness (CRF, as determined by maximal oxygen uptake).

RESULTS

MetS z-score was similarly reduced over time in both groups (P = 0.244 for group-time interaction). A quasi-significant and significant group-time interaction was found for MetS number of factors (P = 0.004) and CRF (P < 0.001), respectively. Thus, MetS factors tended to decrease over time only in the exercise group with no change in the control group, whereas CRF increased from baseline to 5-yr assessment in the exercise group (by 1.1 MET, P < 0.001) but decreased in the control group (-0.5 MET, P = 0.025). Medicine use score increased twofold from baseline to 5-yr follow-up in the control group (P < 0.001) but did not significantly change (10%, P = 0.52) in the exercise group (P < 0.001 for group-time interaction). The proportion of medicated patients who had to increase antihypertensive (P < 0.001), glucose-lowering (P = 0.036), or total medication (P < 0.0001) over the 5-yr period was lower in the exercise than that in the control group.

CONCLUSIONS

Exercise training can attenuate the increase in medication that would be otherwise required to manage MetS over a 5-yr period.

Effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness: A multi-country cluster randomized controlled trial

PURPOSE

To examine the effects of a school-based karate intervention on academic achievement, psychosocial functioning, and physical fitness in children aged 7-8 years.

METHODS

Twenty schools in 5 different European countries (2 second-grade classrooms per school) participated in a cluster randomized controlled trial (Sport at School trial). Participants were assigned to either a control group, which continued with their habitual physical education lessons, or to an intervention group, which replaced these lessons with a 1-year karate intervention (Karate Mind and Movement program). A total of 721 children (344 girls and 377 boys, 7.4 ± 0.5 years old, mean ± standard deviation) completed the study, of which 333 and 388 were assigned to the control group and intervention group, respectively. Outcomes included academic performance (average grade), psychosocial functioning (Strengths and Difficulties Questionnaire for parents), and different markers of physical fitness (cardiorespiratory fitness, balance, and flexibility).

RESULTS

The intervention provided small but significant benefits compared to the control group for academic achievement (d = 0.16; p = 0.003), conduct problems (d = -0.28; p = 0.003), cardiorespiratory fitness (d = 0.36; p < 0.001), and balance (d = 0.24; p = 0.015). There was a trend towards significant benefits for flexibility (d = 0.24; p = 0.056). No significant benefits were observed for other variables, including psychosocial difficulties, emotional symptoms, hyperactivity/inattention, peer problems, or prosocial behavior (all p > 0.05).

CONCLUSION

A 1-year school-based karate intervention was effective in improving academic achievement, conduct problems, and physical fitness in primary school children. The results support the inclusion of karate during physical education lessons.

Relationship Between Critical Power and Different Lactate Threshold Markers in Recreational Cyclists

Purpose: To analyze the relationship between critical power (CP) and different lactate threshold (LT2) markers in cyclists.

Methods: Seventeen male recreational cyclists [33 ± 5 years, peak power output (PO) = 4.5 ± 0.7 W/kg] were included in the study. The PO associated with four different fixed (onset of blood lactate accumulation) and individualized (Dmax_exp, Dmax_pol, and LT_Δ1) LT2 markers was determined during a maximal incremental cycling test, and CP was calculated from three trials of 1-, 5-, and 20-min duration. The relationship and agreement between each LT2 marker and CP were then analyzed.

Results: Strong correlations (r = 0.81–0.98 for all markers) and trivial-to-small non-significant differences (Hedges’ g = 0.01–0.17, bias = 1–9 W, and p > 0.05) were found between all LT2 markers and CP with the exception of Dmax_exp, which showed the strongest correlation but was slightly higher than the CP (Hedges’ g = 0.43, bias = 20 W, and p < 0.001). Wide limits of agreement (LoA) were, however, found for all LT2 markers compared with CP (from ±22 W for Dmax_exp to ±52 W for Dmax_pol), and unclear to most likely practically meaningful differences (PO differences between markers >1%, albeit <5%) were found between markers attending to magnitude-based inferences.

Conclusion: LT2 markers show a strong association and overall trivial-to-small differences with CP. Nevertheless, given the wide LoA and the likelihood of potentially meaningful differences between these endurance-related markers, caution should be employed when using them interchangeably.

Effects of physical exercise on plasma brain-derived neurotrophic factor in neurodegenerative disorders: A systematic review and meta-analysis of randomized controlled trials

Neurodegenerative disorders are associated with reduced levels of brain-derived neurotrophic factor (BDNF). We aimed to assess the effect of exercise interventions on plasma BDNF levels in individuals with neurodegenerative disorders. Eighteen randomized controlled trials (RCT) assessing the effects of exercise interventions versus no exercise on plasma BDNF levels in individuals with neurodegenerative disorders (i.e., multiple sclerosis, Parkinson's disease, mild cognitive impairment [MCI] and Alzheimer's disease) were included. Overall, exercise interventions induced a significant increase in plasma BDNF levels (SMD=2.22, 95% CI=1.33-3.12, p<0.001; 18 studies), which was separately confirmed for multiple sclerosis (SMD= 2.40, 95% CI= 1.30-3.50, p<0.001; 10 studies) and Parkinson's disease (SMD= 10.00, 95% CI= 2.48-17.51, p=0.009; 3 studies), with a non-significant trend also observed for MCI (SMD= 1.07, 95% CI= -0.14-2.28, p=0.080; 4 studies). BDNF levels significantly increased regardless of exercise type (p<0.001, p=0.003 and p=0.020 for combined, aerobic and resistance exercise, respectively), weekly exercise volume (p<0.001 for both ≥150 and <150 min/week) and intervention length (p<0.001 for both interventions of ≥12 and <12 weeks). In conclusion, physical exercise interventions increase plasma BDNF levels in individuals with neurodegenerative disorders. PROSPERO registration number: CRD42020199459.

Statistical shape modeling of the hip and the association with hip osteoarthritis: a systematic review

OBJECTIVE

To summarize available evidence on the association between hip shape as quantified by statistical shape modeling (SSM) and the incidence or progression of hip osteoarthritis.

DESIGN

We conducted a systematic search of five electronic databases, based on a registered protocol (available: PROSPERO CRD42020145411). Articles presenting original data on the longitudinal relationship between radiographic hip shape (quantified by SSM) and hip OA were eligible. Quantitative meta-analysis was precluded because of the use of different SSM models across studies. We used the Newcastle-Ottawa Scale (NOS) for risk of bias assessment.

RESULTS

Nine studies (6,483 hips analyzed with SSM) were included in this review. The SSM models used to describe hip shape ranged from 16 points on the femoral head to 85 points on the proximal femur and hemipelvis. Multiple hip shape features and combinations thereof were associated with incident or progressive hip OA. Shape variants that seemed to be consistently associated with hip OA across studies were acetabular dysplasia, cam morphology, and deviations in acetabular version (either excessive anteversion or retroversion).

CONCLUSIONS

Various radiographic, SSM-defined hip shape features are associated with hip OA. Some hip shape features only seem to increase the risk for hip OA when combined together. The heterogeneity of the used SSM models across studies precludes the estimation of pooled effect sizes. Further studies using the same SSM model and definition of hip OA are needed to allow for the comparison of outcomes across studies, and to validate the found associations.

Physical Exercise and Alzheimer's Disease: Effects on Pathophysiological Molecular Pathways of the Disease

Alzheimer’s disease (AD), the most common form of neurodegenerative dementia in adults worldwide, is a multifactorial and heterogeneous disorder characterized by the interaction of genetic and epigenetic factors and the dysregulation of numerous intracellular signaling and cellular/molecular pathways. The introduction of the systems biology framework is revolutionizing the study of complex diseases by allowing the identification and integration of cellular/molecular pathways and networks of interaction. Here, we reviewed the relationship between physical activity and the next pathophysiological processes involved in the risk of developing AD, based on some crucial molecular pathways and biological process dysregulated in AD: (1) Immune system and inflammation; (2) Endothelial function and cerebrovascular insufficiency; (3) Apoptosis and cell death; (4) Intercellular communication; (5) Metabolism, oxidative stress and neurotoxicity; (6) DNA damage and repair; (7) Cytoskeleton and membrane proteins; (8) Synaptic plasticity. Moreover, we highlighted the increasingly relevant role played by advanced neuroimaging technologies, including structural/functional magnetic resonance imaging, diffusion tensor imaging, and arterial spin labelling, in exploring the link between AD and physical exercise. Regular physical exercise seems to have a protective effect against AD by inhibiting different pathophysiological molecular pathways implicated in AD.

Traditional Versus Velocity-Based Resistance Training in Competitive Female Cyclists: A Randomized Controlled Trial

We assessed the effects of a short-term velocity-based resistance training (VBRT, where exercise intensity is individualized based on the loads and repetitions that maximize power output) program compared with traditional resistance training (TRT, where the same number of repetitions and relative load are used for every individual) on body composition, muscle strength/power, and endurance performance in competitive female cyclists. Seventeen participants were randomly assigned to 6 weeks (two sessions/week) of TRT (n = 8) or VBRT (n = 9), during which they maintained their usual endurance program. Both interventions included squat, hip thrust, and split squat exercises. Training loads were continuously registered, and outcomes were measures of muscle strength/power, body composition, and endurance performance (incremental test and 8-min time trial). No differences between TRT and VBRT groups were found for overall internal training loads during resistance training or cycling sessions (p > 0.05). Both interventions led to significant improvements in all strength/power-related outcomes, but VBRT induced greater improvements than TRT in maximum muscle strength and power as assessed with the hip thrust exercise (p < 0.05 for the group by time interaction effect). However, no significant group by time interaction effect was found for body composition or endurance performance-related outcomes. In conclusion, the addition of a short-term intervention of VBRT or TRT to the usual training regimen of competitive female cyclists improves muscle strength/power, albeit VBRT might induce superior gains on maximum strength/power for the hip thrust exercise.