Influence of preterm birth on physical fitness in early childhood

Evidence suggests that preterm birth is associated with an impaired physical fitness later in life, but whether these effects are already visible since early childhood remains unknown. We aimed to compare the physical fitness of preterm preschoolers with that of children born at term. Children aged three to six years and born preterm (<35 weeks) were recruited from a Neonatal Intensive Care Unit, and children born at term (>37 weeks) were included as controls. A variety of physical fitness indicators (strength, cardiorespiratory fitness, agility, flexibility and balance) were assessed with the PREFIT battery and the adapted sit and reach test. Physical activity levels were measured through the PrePAQ questionnaire. A total of 98 preterm children (gestational age 32.4 ± 2.3 weeks, age 5.1 ± 0.8 years) and 74 controls (gestational age 39.9 ± 1.0 weeks, age 4.8 ± 0.9 years) were analysed. Despite no significant differences in physical activity levels (p > 0.05), preterm children showed an overall poorer physical fitness compared to controls. Specifically, preterm children had an impaired handgrip strength (-13.95%, p < 0.001), lower-limb muscle strength (-12.67%, p = 0.003), agility (-14.9%, p = 0.001), cardiorespiratory fitness (-12.73% p = 0.005) and flexibility (-17.04%, p = 0.001) compared to controls. An inverse dose-response association was observed between the level of prematurity and physical fitness, with very preterm children (gestational age ≤32 weeks) presenting the poorest fitness levels. In summary, prematurity seems to impair physical fitness since early childhood, which might support the need for promoting preventive strategies (e.g. fitness monitoring and applying exercise interventions).Highlights Preterm children present an impaired physical fitness compared with peers born at term since early childhood (3-6 years), as reflected by lower muscle strength, agility, flexibility and cardiorespiratory fitness.A greater impairment of physical fitness in observed in children born very preterm (≤32 weeks of gestation).These findings might support the implementation of preventive strategies (e.g. fitness monitoring and exercise training) in preterm children since early childhood.

Obesity, cardiovascular risk, and lifestyle: cross-sectional and prospective analyses in a nationwide Spanish cohort

AIMS

To assess whether overweight and obesity are independently associated with cardiometabolic health [as categorized based on the presence/absence of cardiovascular disease (CVD) risk factors (diabetes, hypercholesterolaemia, or hypertension)], and the role of lifestyle on this association.

METHODS AND RESULTS

A nationwide cohort of Spanish adults (18-64 years) was studied using a cross-sectional design and prospective observational design. Lifestyle-related factors (physical activity, sleeping characteristics, alcohol drinking, and smoking) were registered, and participants were classified as having an 'unhealthy' or 'healthy' cardiometabolic status attending to the presence or absence, respectively, of ≥1 CVD risk factor. A number of 596 111 participants (44 ± 9 years, 67% male) were studied at baseline, with prospective analyses in a subcohort [n = 302 061; median follow-up, 2 years (range, 2 to 5)]. Compared to normal weight, overweight and obesity were associated with a higher prevalence [odds ratio, 1.67 (95% confidence interval, 1.61-1.67) and 2.70 (2.69-2.78), respectively] and incidence [1.62 (1.59-1.67) and 2.70 (2.63-2.78)] of an unhealthy cardiometabolic status. Meeting physical activity guidelines reduced the odds of an unhealthy cardiometabolic status at baseline [0.87 (0.85-0.88)] among individuals with overweight/obesity, as well as of transitioning from a healthy status to an unhealthy status during the follow-up [0.87 (0.84-0.94)]. No significant associations were found for the remainder of lifestyle factors.

CONCLUSION

Overweight and obesity are independently associated with an unhealthy cardiometabolic status. Regular physical activity attenuates not only the prevalence but also the incidence of CVD risk factors.

Laboratory-based determinants of simulated time trial performance in cyclists

Different laboratory-based variables are individually associated with cycling performance, but scarce evidence exists on which of them, when all assessed in combination, could best explain cycling performance. The present study aimed to examine the combined association between laboratory-based endurance, strength/power and body composition indicators with time trial performance in high-level cyclists. Ninety-four male cyclists were recruited (age: 20 ± 3.5 years, maximum oxygen uptake [V̇O2max]: 77.7 ± 5.4 ml · kg-1 · min-1). Participants performed a maximal incremental cycling test for the assessment of endurance indicators (peak power output [PPO], V̇O2max, ventilatory threshold [VT] and respiratory compensation point [RCP]), and an incremental loading test to assess muscle strength and power-related outcomes (1-repetition maximum, mean maximal power) in the squat, lunge and hip-thrust exercises. Body composition was assessed by dual energy X-ray absorptiometry. On a separate visit, participants performed a simulated 8-minute time trial to assess cycling performance (determined as the mean power output attained). Strong-to-very-strong correlations were found between all endurance indicators and time trial performance (most r-values ranging between 0.68-0.92), whereas weaker correlations were found for strength/power (r-values < 0.5) or body composition (r-values < 0.7) indicators. Multivariate regression analyses revealed that VT, RCP and PPO explained together 92% of the variance in time trial performance (p < 0.001), with no significant contribution of the remaining variables. Although different endurance, strength/power and body composition individually correlate with simulated time trial performance in high-level cyclists, the former (and particularly VT, RCP and PPO) show the strongest association when all studied in combination. These findings underscore the importance of endurance capabilities (above strength/power or body composition) for maximizing time trial performance.

Between-Seasons Variability of Cyclists' Peak Performance: A Longitudinal Analysis of "Real-World" Power Output Data in Male Professional Cyclists

PURPOSE

The record power profile (RPP) has gained popularity as a method of monitoring endurance cycling performance. However, the expected variation of cyclists' performance between seasons remains unknown. We aimed to assess the between-seasons variability of peak performance (assessed through the RPP) in male professional cyclists.

METHODS

The study followed a longitudinal observational design. Sixty-one male professional cyclists (age 26 [5] y) with power output data from both training sessions and competitions were analyzed for a median of 4 consecutive seasons (range 2-12). The highest mean maximum power values attained for different durations (from 10 s to 30 min), as well as the resulting critical power, were determined for each season. Within-cyclist variability between seasons was assessed, and the upper threshold of expected changes (ie, twice the normal coefficient of variation) was determined.

RESULTS

All mean maximum power values showed an overall high agreement and low variability between seasons (intraclass correlation coefficient [ICC] = .76-.88 and coefficient of variation [CV] = 3.2%-5.9%), with the lowest variability observed for long efforts (>1 min). Critical power showed an ICC and CV of .79 (95% CI, .70-.85) and 3.3% (95% CI, 3.0%-3.7%), respectively. Upper thresholds of expected variation were <12% for short efforts (≤1 min) and <8% for long efforts.

CONCLUSIONS

"Real-world" peak performance assessed through the RPP shows a low variability between seasons in male professional cyclists-especially for long efforts-with expected variation being around 6% and 3% for short (≤1 min) and long efforts, respectively, and with changes >12% and >8%, respectively, being infrequent for these effort durations.

Neurocognitive outcomes in pediatric brain tumors after treatment with proton versus photon radiation: a systematic review and meta-analysis

BACKGROUND

Advances in cancer treatments, particularly the development of radiation therapy, have led to improvements in survival outcomes in children with brain tumors. However, radiation therapy is associated with significant long-term neurocognitive morbidity. The present systematic review and meta-analysis aimed to compare the neurocognitive outcomes of children and adolescents with brain tumors treated with photon radiation (XRT) or proton therapy (PBRT).

METHODS

A systematic search was conducted (PubMed, Embase, Cochrane, and Web of Science from inception until 02/01/2022) for studies comparing the neurocognitive outcomes of children and adolescents with brain tumors treated with XRT vs. PBRT. The pooled mean differences (expressed as Z scores) were calculated using a random effects method for those endpoints analyzed by a minimum of three studies.

RESULTS

Totally 10 studies (n = 630 patients, average age range: 1-20 years) met the inclusion criteria. Patients who had received PBRT achieved significantly higher scores (difference in Z scores ranging from 0.29-0.75, all P < 0.05 and significant in sensitivity analyses) after treatment than those who had received XRT for most analyzed neurocognitive outcomes (i.e., intelligence quotient, verbal comprehension and perceptual reasoning indices, visual motor integration, and verbal memory). No robust significant differences (P > 0.05 in main analyses or sensitivity analyses) were found for nonverbal memory, verbal working memory and working memory index, processing speed index, or focused attention.

CONCLUSIONS

Pediatric brain tumor patients who receive PBRT achieve significantly higher scores on most neurocognitive outcomes than those who receive XRT. Larger studies with long-term follow-ups are needed to confirm these results.

Obesity and the risk of cardiometabolic diseases

The prevalence of obesity has reached pandemic proportions, and now approximately 25% of adults in Westernized countries have obesity. Recognized as a major health concern, obesity is associated with multiple comorbidities, particularly cardiometabolic disorders. In this Review, we present obesity as an evolutionarily novel condition, summarize the epidemiological evidence on its detrimental cardiometabolic consequences and discuss the major mechanisms involved in the association between obesity and the risk of cardiometabolic diseases. We also examine the role of potential moderators of this association, with evidence for and against the so-called 'metabolically healthy obesity phenotype', the 'fatness but fitness' paradox or the 'obesity paradox'. Although maintenance of optimal cardiometabolic status should be a primary goal in individuals with obesity, losing body weight and, particularly, excess visceral adiposity seems to be necessary to minimize the risk of cardiometabolic diseases.

Exercise effects on functional capacity and quality of life in older patients with colorectal cancer: study protocol for the ECOOL randomized controlled trial

BACKGROUND

Surgery and treatment for colorectal cancer (CRC) in the elderly patient increase the risk of developing post-operative complications, losing functional independence, and worsening health-related quality of life (HRQoL). There is a lack of high-quality randomized controlled trials evaluating the potential benefit of exercise as a countermeasure. The primary aim of this study is to evaluate the effectiveness of a home-based multicomponent exercise program for improving HRQoL and functional capacity in older adults undergoing CRC surgery and treatment.

METHODS

This randomized, controlled, observer-blinded, single-center trial aims to randomize 250 patients (>74 years) to either an intervention or a control group (i.e., usual care). The intervention group will perform an individualized home-based multicomponent exercise program with weekly telephone supervision from diagnosis until three months post-surgery. The primary outcomes will be HRQoL (EORTC QLQ-C30; CR29; and ELD14) and functional capacity (Barthel Index and Short Physical Performance Battery), which will be assessed at diagnosis, at discharge, and one, three, and six months after surgery. Secondary outcomes will be frailty, physical fitness, physical activity, inspiratory muscle function, sarcopenia and cachexia, anxiety and depression, ambulation ability, surgical complications, and hospital length of stay, readmission and mortality.

DISCUSSION

This study will examine the effects of an exercise program in older patients with CRC across a range of health-related outcomes. Expected findings are improvement in HRQoL and physical functioning. If proven effective, this simple exercise program may be applied in clinical practice to improve CRC care in older patients.

TRIAL REGISTRATION

ClinicalTrials.gov ID: NCT05448846.

Effects of physical exercise on physical function in older adults in residential care: a systematic review and network meta-analysis of randomised controlled trials

BACKGROUND

Physical exercise is effective at attenuating ageing-related physical decline in general, but evidence of its benefits for older adults in residential care, who often have functional dependency, multimorbidity, and polypharmacy, is inconclusive. We aimed to establish the effects of exercise interventions on the physical function of this population.

METHODS

For this systematic review and network meta-analysis, we searched PubMed, Web of Science, Cochrane Library, Rehabilitation & Sports Medicine Source, and SPORTDiscus to identify randomised controlled trials assessing the effects of exercise interventions (vs usual care) on physical function (ie, functional independence, physical performance, and other related measures, such as muscle strength, balance, or flexibility) in adults aged 60 years or older living in residential care. Relevant studies published in English or Spanish up to Jan 12, 2023, were included in the systematic review. The quality of studies was assessed using the Tool for the Assessment of Study Quality and Reporting in Exercise (TESTEX) score. A network meta-analysis was performed for physical function-related outcomes reported in at least ten studies, with subanalyses for specific intervention (ie, exercise type, training volume, and study duration) and participant (eg, having cognitive impairment or dementia, pre-frail or frail status, and being functionally dependent) characteristics. The study protocol was registered on PROSPERO (CRD42021247809).

FINDINGS

147 studies (11 609 participants, with mean ages ranging from 67 years [SD 9] to 92 years [2]) were included in the systematic review, and were rated as having overall good quality (median TESTEX score 9 [range 3-14]). In the meta-analysis (including 105 studies, n=7759 participants), exercise interventions were associated with significantly improved overall physical function, with a standardised mean difference [SMD] of 0·13 (95% credible interval [CrI] 0·04-0·21), which was confirmed in all analysed subpopulations. The strongest association was observed with 110-225 min per week of exercise, and the greatest improvements were observed with 170 min per week (SMD 0·36 [95% CrI 0·20-0·52]). No significant differences were found between exercise types. Subanalyses showed significant improvements for almost all analysed physical function-related outcomes (Barthel index, five-times sit-to-stand test, 30-s sit-to-stand test, knee extension, hand grip strength, bicep curl strength, Short Physical Performance Battery, 6-min walking test, walking speed, Berg balance scale, and sit-and-reach test). Large heterogeneity was found between and within studies in terms of population and intervention characteristics.

INTERPRETATION

Exercise interventions are associated with improved physical function in older adults in residential care, and should, therefore, be routinely promoted in long-term care facilities.

FUNDING

None.

TRANSLATION

For the Spanish translation of the abstract see Supplementary Materials section.

Exercise benefits in cardiovascular diseases: from mechanisms to clinical implementation

There is a pandemic of physical inactivity that appears to parallel the widespread prevalence of cardiovascular disease (CVD). Yet, regular physical activity (PA) and exercise can play an important role not only in primary cardiovascular prevention but also in secondary prevention. This review discusses some of the main cardiovascular effects of PA/exercise and the mechanisms involved, including a healthier metabolic milieu with attenuation of systemic chronic inflammation, as well as adaptations at the vascular (antiatherogenic effects) and heart tissue (myocardial regeneration and cardioprotection) levels. The current evidence for safe implementation of PA and exercise in patients with CVD is also summarized.

Dietary phosphate restriction prevents the appearance of sarcopenia signs in old mice

BACKGROUND

Sarcopenia is defined by the progressive and generalized loss of muscle mass and function associated with aging. We have previously proposed that aging-related hyperphosphataemia is linked with the appearance of sarcopenia signs. Because there are not effective treatments to prevent sarcopenia, except for resistance exercise, we propose here to analyse whether the dietary restriction of phosphate could be a useful strategy to improve muscle function and structure in an animal model of aging.

METHODS

Five-month-old (young), 24-month-old (old) and 28-month-old (geriatric) male C57BL6 mice were used. Old and geriatric mice were divided into two groups, one fed with a standard diet (0.6% phosphate) and the other fed with a low-phosphate (low-P) diet (0.2% phosphate) for 3 or 7 months, respectively. A phosphate binder, Velphoro®, was also supplemented in a group of old mice, mixed with a standard milled diet for 3 months. Muscle mass was measured by the weight of gastrocnemius and tibial muscles, and quality by nuclear magnetic resonance imaging (NMRI) and histological staining assays. Muscle strength was measured by grip test and contractile properties of the tibialis muscle by electrical stimulation of the common peroneal nerve. Gait parameters were analysed during the spontaneous locomotion of the mice with footprinting. Orientation and motor coordination were evaluated using a static rod test.

RESULTS

Old mice fed with low-P diet showed reduced serum phosphate concentration (16.46 ± 0.77 mg/dL young; 21.24 ± 0.95 mg/dL old; 17.46 ± 0.82 mg/dL low-P diet). Old mice fed with low-P diet displayed 44% more mass in gastrocnemius muscles with respect to old mice (P = 0.004). NMRI revealed a significant reduction in T2 relaxation time (P = 0.014) and increased magnetization transfer (P = 0.045) and mean diffusivity (P = 0.045) in low-P diet-treated mice compared with their coetaneous. The hypophosphataemic diet increased the fibre size and reduced the fibrotic area by 52% in gastrocnemius muscle with respect to old mice (P = 0.002). Twitch force and tetanic force were significantly increased in old mice fed with the hypophosphataemic diet (P = 0.004 and P = 0.014, respectively). Physical performance was also improved, increasing gait speed by 30% (P = 0.032) and reducing transition time in the static rod by 55% (P = 0.012). Similar results were found when diet was supplemented with Velphoro®.

CONCLUSIONS

The dietary restriction of phosphate in old mice improves muscle quantity and quality, muscle strength and physical performance. Similar results were found using the phosphate binder Velphoro®, supporting the role of phosphate in the impairment of muscle structure and function that occurs during aging.

Recent Advances in Nutrition for Disease Prevention and Sports Performance Enhancement

The important role of nutrition on both health and sports performance, and particularly its joint association with physical exercise, is becoming increasingly clear in recent years [...].

School-based physical activity interventions and language skills: a systematic review and meta-analysis of randomized controlled trials

OBJECTIVES

School-based physical activity (PA) interventions have proven beneficial for improving cognitive performance and overall academic achievement, but their benefits on language skills remain unclear. We aimed to assess the effects of school-based PA interventions on language skills in children and adolescents.

DESIGN

Systematic review with meta-analysis.

METHODS

A systematic search was performed in PubMed, PsycINFO and Scopus until September 10th, 2022. We included randomized controlled trials (RCTs) that performed a school-based PA intervention in children/adolescents and that assessed language-related outcomes (i.e., reading, spelling, vocabulary, verbal fluency, comprehension and grammar) or language school grades. Random effect meta-analyses were conducted to pool study results.

RESULTS

Thirty-one studies (18,651 participants) were finally included. Significant benefits were observed for reading (standardized mean difference [SMD]: 0.15; 95% confidence interval [CI]: 0.08, 0.22), vocabulary (SMD: 0.71; 95%CI: 0.44, 0.97), and comprehension (SMD: 0.24; 95%CI: 0.09, 0.40), with a non-significant trend (p = 0.083) also observed for language school grades (SMD: 0.40; 95%CI: -0.05, 0.86). No significant benefits were observed for spelling or verbal fluency (both p > 0.05), and no meta-analysis could be performed for grammar skills. No consistent differences were observed between integrated (i.e., performing PA along with the academic content) and non-integrated PA interventions (e.g., extra physical education lessons).

CONCLUSIONS

School-based PA interventions appear as an effective strategy for improving different language-related skills, although further research is needed to determine how interventions' and participants' characteristics moderate these effects.

Effects of physical activity and exercise interventions on Alzheimer's disease: an umbrella review of existing meta-analyses

INTRODUCTION

During the last decade, physical activity (PA) (or "exercise") has been identified as one of the main modifiable factors that influence the development of Alzheimer's disease (AD) pathophysiology. We performed an umbrella review to summarize the evidence on the association between PA/exercise and the risk of developing AD risk, and the effect of exercise interventions on the progression of AD.

METHODS

A systematic search was performed in PubMed, SportDiscus, Cochrane Library and Web of Science (March 2022) to identify meta-analyses assessing the association between PA and the incidence of AD, and assessing the effect of exercise interventions on patients with AD.

RESULTS

Twenty-one studies were included. The results with strongest evidence revealed the positive effects of PA on AD risk. Specifically, meeting the WHO recommendations for PA was associated with a lower risk of AD. They also revealed positive effects of exercise on cognitive function, physical performance, and functional independence.

CONCLUSIONS

There is strong evidence of a protective effect of regular PA against AD risk; however, the dose-response association remains unclear. Physical exercise seems to improve several dimensions in patients with AD, although research is warranted to elucidate the exercise characteristics that promote the greatest benefits.

Muscle glycogen unavailability and fat oxidation rate during exercise: Insights from McArdle disease

Carbohydrate availability affects fat metabolism during exercise; however, the effects of complete muscle glycogen unavailability on maximal fat oxidation (MFO) rate remain unknown. Our purpose was to examine the MFO rate in patients with McArdle disease, comprising an inherited condition caused by complete blockade of muscle glycogen metabolism, compared to healthy controls. Nine patients (three women, aged 36 ± 12 years) and 12 healthy controls (four women, aged 40 ± 13 years) were studied. Several molecular markers of lipid transport/metabolism were also determined in skeletal muscle (gastrocnemius) and white adipose tissue of McArdle (Pygm p.50R*/p.50R*) and wild-type male mice. Peak oxygen uptake ( V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ ), MFO rate, the exercise intensity eliciting MFO rate (FATmax) and the MFO rate-associated workload were determined by indirect calorimetry during an incremental cycle-ergometer test. Despite having a much lower V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ (24.7 ± 4 vs. 42.5 ± 11.4 mL kg^-1  min^-1 , respectively; P < 0.0001), patients showed considerably higher values for the MFO rate (0.53 ± 0.12 vs. 0.33 ± 0.10 g min^-1 , P = 0.001), and for the FATmax (94.4 ± 7.2 vs. 41.3 ± 9.1 % of V ̇ O 2 peak ${\dot V_{{{\rm{O}}_{\rm{2}}}{\rm{peak}}}}$ , P < 0.0001) and MFO rate-associated workload (1.33 ± 0.35 vs. 0.81 ± 0.54 W kg^-1 , P = 0.020) than controls. No between-group differences were found overall in molecular markers of lipid transport/metabolism in mice. In summary, patients with McArdle disease show an exceptionally high MFO rate, which they attained at near-maximal exercise capacity. Pending more mechanistic explanations, these findings support the influence of glycogen availability on MFO rate and suggest that these patients develop a unique fat oxidation capacity, possibly as an adaptation to compensate for the inherited blockade in glycogen metabolism, and point to MFO rate as a potential limiting factor of exercise tolerance in this disease. KEY POINTS: Physically active McArdle patients show an exceptional fat oxidation capacity. Maximal fat oxidation rate occurs near-maximal exercise capacity in these patients. McArdle patients' exercise tolerance might rely on maximal fat oxidation rate capacity. Hyperpnoea might cloud substrate oxidation measurements in some patients. An animal model revealed overall no higher molecular markers of lipid transport/metabolism.

Myocardial Fibrosis and Coronary Calcifications Caused by Endurance Exercise? Insights from Former Professional Cyclists

PURPOSE

This study aimed to compare the prevalence of myocardial fibrosis and coronary calcification in individuals who have performed very high levels of strenuous endurance exercise (SEE; former male professional cyclists) and sex/age-matched controls.

METHODS

We used a retrospective cohort study design, where cases were former finishers of ≥1 Grand Tour (Tour de France, Giro d' Italia or Vuelta a España) and controls were untrained individuals free of cardiovascular risk. All participants underwent cardiac magnetic resonance and cardiac computer tomography in the same center during years 2020-2021 to detect myocardial fibrosis (late gadolinium enhancement) and to quantify coronary calcium, respectively.

RESULTS

Twenty-three cases (age, 46 ± 6 yr) and 59 controls (47 ± 7 yr) were studied. Fibrotic patches were evidenced only in the left ventricle, with a higher prevalence in cases (23% vs 2% in controls, P = 0.006). However, fibrotic tissue was nonischemic and of low extension (0.6% ± 0.4% of left ventricle mass), and no significant differences were found between cases and controls for native T1 or T2 values. No between-group differences were found for coronary calcium indicators, including Agatston or density scores. Subanalyses revealed no differences attending to whether cases were still performing regular SEE ( n = 8) or not ( n = 15) after professional retirement.

CONCLUSIONS

Although former professional cyclists seemed to show a greater prevalence of myocardial fibrosis, the extension of fibrotic tissue was minimal and no alterations were found in coronary calcification indicators. While keeping in mind the low sample size of the cases' group, our results do not support evidence for major cardiac maladaptations with long-term exposure to SEE, at least in middle-age adults.

Pre-sleep protein supplementation in professional cyclists during a training camp: a three-arm randomized controlled trial

Background

The effects of pre-sleep protein supplementation on endurance athletes remain unclear, particularly whether its potential benefits are due to the timing of protein intake or solely to an increased total protein intake. We assessed the effects of pre-sleep protein supplementation in professional cyclists during a training camp accounting for the influence of protein timing.

Methods

Twenty-four professional U23 cyclists (19 ± 1 years, peak oxygen uptake: 79.8 ± 4.9 ml/kg/min) participated in a six-day training camp. Participants were randomized to consume a protein supplement (40 g of casein) before sleep (n = 8) or in the afternoon (n = 8), or an isoenergetic placebo (40 g of carbohydrates) before sleep (n = 8). Indicators of fatigue/recovery (Hooper index, Recovery-Stress Questionnaire for Athletes, countermovement jump), body composition, and performance (1-, 5-, and 20-minute time trials, as well as the estimated critical power) were assessed as study outcomes.

Results

The training camp resulted in a significant (p < 0.001) increase in training loads (e.g. training stress score of 659 ± 122 per week during the preceding month versus 1207 ± 122 during the training camp), which induced an increase in fatigue indicators (e.g. time effect for Hooper index p < 0.001) and a decrease in performance (e.g. time effect for critical power p = 0.002). Protein intake was very high in all the participants (>2.5 g/kg on average), with significantly higher levels found in the two protein supplement groups compared to the placebo group (p < 0.001). No significant between-group differences were found for any of the analyzed outcomes (all p > 0.05).

Conclusions

Protein supplementation, whether administered before sleep or earlier in the day, exerts no beneficial effects during a short-term strenuous training period in professional cyclists, who naturally consume a high-protein diet.

Is the Record Power Profile Repeatable? A Practical Analysis and Interpretation in Professional Cyclists

ABSTRACT

Muriel, X, Hernández-Belmonte, A, Mateo-March, M, Valenzuela, PL, Zabala, M, Barranco-Gil, D, Lucia, A, and Pallares, JG. Is the record power profile repeatable? A practical analysis and interpretation in professional cyclists. J Strength Cond Res XX(X): 000-000, 2022-This study assessed the repeatability of the Record Power Profile (RPP, i.e., the highest power output that a cyclist can attain for different effort durations under field-based conditions). We registered the RPP of 12 professional cyclists (age 32 ± 5 years) for efforts lasting between 30 seconds and 60 minutes during 3 periods of a season, each of 23-day duration: preparation (including training data only), specific (training and competition data), and competition (competition data only) periods. Repeatability was assessed using the highest 2 (RPP 2 ), 3 (RPP 3 ), and 5 (RPP 5 ) values of mean maximum power obtained by the cyclists for each effort duration in each of the 3 periods. Smaller standard errors of measurement ( SEM ) were found as the competitive period approached, especially for short-duration efforts (i.e., 30 seconds, 1 minute, and 5 minutes, where SEM ranged from 4.3 to 12.5%, 4.1-8.5%, and 2.6-7.0% in the preparation, specific, and competition periods, respectively). However, similar SEM values were found in the 3 periods for RPP 2 , RPP 3 , or RPP 5. In conclusion, the RPP appears as a repeatable parameter for monitoring field-based performance within the different phases of the season in professional cyclists.

Physical Exercise and the Hallmarks of Breast Cancer: A Narrative Review

Growing evidence suggests that, among the different molecular/cellular pathophysiological mechanisms associated with cancer, there are 14 hallmarks that play a major role, including: (i) sustaining proliferative signaling, (ii) evading growth suppressors, (iii) activating invasion and metastasis, (iv) enabling replicative immortality, (v) inducing angiogenesis, (vi) resisting cell death, (vii) reprogramming energy metabolism, (viii) evading immune destruction, (ix) genome instability and mutations, (x) tumor-promoting inflammation, (xi) unlocking phenotypic plasticity, (xii) nonmutational epigenetic reprogramming, (xiii) polymorphic microbiomes, and (xiv) senescent cells. These hallmarks are also associated with the development of breast cancer, which represents the most prevalent tumor type in the world. The present narrative review aims to describe, for the first time, the effects of physical activity/exercise on these hallmarks. In summary, an active lifestyle, and particularly regular physical exercise, provides beneficial effects on all major hallmarks associated with breast cancer, and might therefore help to counteract the progression of the disease or its associated burden.

Combined exercise intervention in a mouse model of high-risk neuroblastoma: effects on physical, immune, tumor and clinical outcomes

Background

Exercise might exert anti-tumoral effects in adult cancers but this question remains open in pediatric tumors, which frequently show a different biology compared to adult malignancies. We studied the effects of an exercise intervention on physical function, immune variables and tumoral response in a preclinical model of a highly aggressive pediatric cancer, high-risk neuroblastoma (HR-NB).

Methods

6-8-week-old male mice with orthotopically-induced HR-NB were assigned to a control (N = 13) or exercise (5-week combined [aerobic+resistance]) group (N = 17). Outcomes included physical function (cardiorespiratory fitness [CRF] and muscle strength), as well as related muscle molecular indicators, blood and tumor immune cell and molecular variables, tumor progression, clinical severity, and survival.

Results

Exercise attenuated CRF decline (p=0.029 for the group-by-time interaction effect), which was accompanied by higher muscle levels of oxidative capacity (citrate synthase and respiratory chain complexes III, IV and V) and an indicator of antioxidant defense (glutathione reductase) in the intervention arm (all p≤0.001), as well as by higher levels of apoptosis (caspase-3, p=0.029) and angiogenesis (vascular endothelial growth factor receptor-2, p=0.012). The proportion of 'hot-like' (i.e., with viable immune infiltrates in flow cytometry analyses) tumors tended to be higher (p=0.0789) in the exercise group (76.9%, vs. 33.3% in control mice). Exercise also promoted greater total immune (p=0.045) and myeloid cell (p=0.049) infiltration within the 'hot' tumors, with a higher proportion of two myeloid cell subsets (CD11C+ [dendritic] cells [p=0.049] and M2-like tumor-associated macrophages [p=0.028]), yet with no significant changes in lymphoid infiltrates or in cirulating immune cells or chemokines/cytokines. No training effect was found either for muscle strength or anabolic status, cancer progression (tumor weight and metastasis, tumor microenvironment), clinical severity, or survival.

Conclusions

Combined exercise appears as an effective strategy for attenuating physical function decline in a mouse model of HR-NB, also exerting some potential immune benefits within the tumor, which seem overall different from those previously reported in adult cancers.

Normative Values for Sport-Specific Left Ventricular Dimensions and Exercise-Induced Cardiac Remodeling in Elite Spanish Male and Female Athletes

Background

There is debate about the magnitude of geometrical remodeling [i.e., left ventricle (LV) cavity enlargement vs. wall thickening] in the heart of elite athletes, and no limits of normality have been yet established for different sports. We aimed to determine sex- and sport-specific normative values of LV dimensions in elite white adult athletes.

Methods

This was a single-center, retrospective study of Spanish elite athletes. Athletes were grouped by sport and its relative dynamic/static component (Mitchell’s classification). LV dimensions were measured with two-dimensional-guided M-mode echocardiography imaging to compute normative values. We also developed an online and app-based calculator (https://sites.google.com/lapolart.es/athlete-lv/welcome?authuser=0) to provide clinicians with sports- and Mitchell’s category-specific Z-scores for different LV dimensions.

Results

We studied 3282 athletes (46 different sports, 37.8% women, mean age 23 ± 6 years). The majority (85.4%) showed normal cardiac geometry, particularly women (90.9%). Eccentric hypertrophy was relatively prevalent (13.4%), and concentric remodeling or hypertrophy was a rare finding (each < 0.8% of total). The proportion of normal cardiac geometry and eccentric hypertrophy decreased and increased, respectively, with the dynamic (in both sexes) or static component (in male athletes) of the sport irrespective of the other (static or dynamic) component. The 95th percentile values of LV dimensions did not exceed the following limits in any of the Mitchell categories: septal wall thickness, 12 mm (males) and 10 mm (females); LV posterior wall, 11 mm and 10 mm; and LV end-diastolic diameter, 64 mm and 57 mm.

Conclusions

The majority of elite athletes had normal LV geometry, and although some presented with LV eccentric hypertrophy, concentric remodeling or hypertrophy was very uncommon. The present study provides sport-specific normative values that can serve to identify those athletes for whom a detailed examination might be recommendable (i.e., those exceeding the 95th percentile for their sex and sport).

Supplementary Information

The online version contains supplementary material available at 10.1186/s40798-022-00510-2.

Low aerobic capacity in McArdle disease: A role for mitochondrial network impairment?

BACKGROUND

McArdle disease is caused by myophosphorylase deficiency and results in complete inability for muscle glycogen breakdown. A hallmark of this condition is muscle oxidation impairment (e.g., low peak oxygen uptake (VO_2peak)), a phenomenon traditionally attributed to reduced glycolytic flux and Krebs cycle anaplerosis. Here we hypothesized an additional role for muscle mitochondrial network alterations associated with massive intracellular glycogen accumulation.

METHODS

We analyzed in depth mitochondrial characteristics-content, biogenesis, ultrastructure-and network integrity in skeletal-muscle from McArdle/control mice and two patients. We also determined VO_2peak in patients (both sexes, N = 145) and healthy controls (N = 133).

RESULTS

Besides corroborating very poor VO_2peak values in patients and impairment in muscle glycolytic flux, we found that, in McArdle muscle: (a) damaged fibers are likely those with a higher mitochondrial and glycogen content, which show major disruption of the three main cytoskeleton components-actin microfilaments, microtubules and intermediate filaments-thereby contributing to mitochondrial network disruption in skeletal muscle fibers; (b) there was an altered subcellular localization of mitochondrial fission/fusion proteins and of the sarcoplasmic reticulum protein calsequestrin-with subsequent alteration in mitochondrial dynamics/function; impairment in mitochondrial content/biogenesis; and (c) several OXPHOS-related complex proteins/activities were also affected.

CONCLUSIONS

In McArdle disease, severe muscle oxidative capacity impairment could also be explained by a disruption of the mitochondrial network, at least in those fibers with a higher capacity for glycogen accumulation. Our findings might pave the way for future research addressing the potential involvement of mitochondrial network alterations in the pathophysiology of other glycogenoses.

Sport Participation and Academic Performance in Young Elite Athletes

Strong evidence supports physical activity and fitness levels being positively associated with cognitive performance and overall academic performance in youth. This also applies to sports participation. However, whether participation in sports at the elite level is associated with greater academic performance remains unknown. Thus, the present study aimed to compare the academic performance of young elite athletes to that of control students, as well as to analyze whether the type of sport mediates these results. Between 2010 and 2019, all students from the last Baccalaureate course of the Spanish Elite Sport High School-which also includes non-elite athletes and recreational athlete students, who were categorized as controls-participated in this study. Academic performance was assessed through both the grade point average of the two last Baccalaureate courses and through the average grades from the University Entrance Examinations. Athletes were categorized attending to different sport classifications. A total of 1126 adolescents (570 girls, 18.2 ± 0.6 years) participated in the study, of which 483 and 643 were categorized as elite athletes and control students, respectively. Elite athletes attained a lower overall academic performance than controls (p < 0.001), which was confirmed for both sexes (p < 0.001). These differences were separately confirmed for most academic subjects (p < 0.05), as well as when attending to different sport classifications (all p > 0.05). Young elite athletes attained a lower academic performance than their non-elite peers, regardless of their type of sport. These findings highlight the importance of programs aimed at facilitating dual careers among young elite athletes.

Field-Derived Maximal Power Output in Cycling: An Accurate Indicator of Maximal Performance Capacity?

PURPOSE

To determine the validity of field-derived mean maximum power (MMP) values for monitoring maximal cycling endurance performance.

METHODS

Twenty-seven male professional cyclists performed 3 timed trials (TTs) of 1-, 5-, and 20-minute duration that were used as the gold standard reference. Field-based power output data (3336 files; 124 [25] per cyclist) were registered during the preparatory (60 d pre-TT, including training data only) and specific period of the season (60 d post-TT, including both training and competitions). Comparisons were made between TT performance (mean power output) and MMP values obtained for efforts of the same duration as TT (MMP of 1-, 5-, and 20-min duration). The authors also compared TT- and MMP-derived values of critical power (CP) and anaerobic work capacity.

RESULTS

A large correlation (P < .001, r > .65) was found between MMP and TT performance regardless of the effort duration or season period. However, considerable differences (P < .05, standard error of measurement [SEM] > 5%) were found between MMP and TT values for all effort durations in the preparatory period, as well as for the derived CP and anaerobic work capacity. Significant differences were also found between MMP and TT of 1 minute in the specific period, as well as for anaerobic work capacity, yet with no differences for MMP of 5- and 20-minute duration or the derived CP (P > .05, SEM < 5%).

CONCLUSION

MMP values (for efforts ≥5 min) and the associated CP obtained from both training sessions and competitions can be considered overall accurate indicators of the cyclist's maximal capabilities, but specific tests might be necessary for shorter efforts or when considering training sessions only.