Influence of Preterm Birth and Low Birthweight on Physical Fitness: A Systematic Review, Meta-Analysis, and Meta-Regression.

BACKGROUND: Preterm birth and low birthweight (LBW) might be associated with reduced physical fitness, although evidence remains inconclusive. OBJECTIVE: To examine the influence of preterm birth and LBW on physical fitness, as well as to assess whether variables such as gestational age, birthweight, or age at assessment moderate these effects. METHODS: PubMed, Scopus, and PsycINFO were systematically searched from inception to 7 December 2023 for case-control and cohort studies analyzing the association between preterm birth or LBW (or gestational age or birthweight as continuous variables) with at least one physical fitness-related outcome (i.e., cardiorespiratory fitness (CRF), muscle strength, flexibility, speed, agility). Random-effects meta-analysis and meta-regression models were used to estimate the pooled effect size, as well as to examine potential associations between the magnitude of the effect and gestational age, birthweight, or age at assessment. RESULTS: Fifty-two studies (n = 920,603 participants, average age ranging from 4.7 to 34.4 years) were included. Preterm birth was associated with reduced CRF (standardized mean difference (SMD) = -0.38, 95% confidence interval (CI) = -0.51 to -0.25) and muscle strength (SMD = -0.44, 95% CI = -0.79 to -0.08). LBW was associated with reduced CRF (SMD = -0.40, 95% CI = -0.64 to -0.17), muscle strength (SMD = -0.18, 95% CI = -0.24 to -0.13), flexibility (SMD = -0.11, 95% CI = -0.22 to -0.01), and agility (SMD = -0.99, 95% CI = -1.91 to -0.07). Meta-regression analyses showed that a lower gestational age or birthweight were associated with larger reductions in physical fitness, whereas no consistent association was found for the age at assessment. CONCLUSION: Both preterm birth and LBW seem associated with reduced physical fitness regardless of age, with larger reductions overall observed in individuals with lower gestational age or birthweight. These findings might support the implementation of preventive strategies (e.g., fitness monitoring and physical exercise interventions) in these populations through the life course. PROSPERO registration: CRD42021231845.

Is all work the same? Performance after accumulated work of differing intensities in male professional cyclists.

OBJECTIVES: Although the ability to attenuate power output (PO) declines after accumulated work (i.e., 'durability') is increasingly recognized as a major determinant of cycling performance, the potential role of the intensity of the previous work is unclear. We assessed the effect of work-matched levels of accumulated work at different intensities on performance in male professional cyclists. DESIGN: Observational field-based study. METHODS: PO data was registered in 17 cyclists during a competition season, and the critical power (CP) was repeatedly determined every 4 weeks from training sessions and competitions. Participants' maximum mean power (MMP) for different durations (5 s, 5 min, 10 min, and 20 min) and the CP were determined under 'fresh' conditions (0 kJ·kg-1) and after varying levels of accumulated work (2.5, 5.0 and 7.5 kJ·kg-1) at intensities below and above the CP. RESULTS: A significant decline was found for all MMP values following all levels of accumulated work above the CP (-4.0 %, -1.7 %, -1.8 %, and -3.2 % for 30s, 5 min, 10 min and 20 min-MMP, respectively; all p < 0.001), versus no change after any level of accumulated work below the CP (all p > 0.05). Similar results were observed for the CP, which decreased after all levels of accumulated work above (-2.2 %, -6.1 %, and -16.2 %, after 2.5, 5.0 and 7.5 kJ·kg-1, p < 0.001) but not below this indicator (p > 0.05). CONCLUSIONS: In male professional cyclists, accumulated work above the CP impairs performance compared with work-matched, albeit less intense efforts. This raises concerns on the use of mechanical work per se as a single fatigue/stress indicator in these athletes.

Physical Activity and Cognitive Performance in Early Childhood: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

BACKGROUND: Growing evidence suggests that physical activity (PA) could improve cognitive performance in youths, but whether these effects occur from early childhood remains unclear. OBJECTIVE: To summarize evidence on the effects of PA interventions on cognitive performance in early childhood. METHODS: We performed a systematic search in PubMed, Scopus, Web of Science and PsycINFO (from inception to 6 September 2023) for randomized controlled trials assessing the effects of PA interventions (≥ 3 weeks) on cognitive-related outcomes in early childhood (3-6 years). We conducted a random-effects meta-analysis when five or more studies assessed a given outcome. The potential moderating role of participant (e.g., age) and intervention characteristics (e.g., duration, volume, intensity, cognitive engagement) was also assessed. RESULTS: We found a total of 24 studies (N = 3483 children) that were deemed to be of overall fair methodological quality. PA interventions were supervised and lasted between 3 and 24 weeks. The most common session duration was 30 min, with a frequency of two sessions per week. Pooled analyses revealed that PA interventions have positive effects on all analysed outcomes, including attention (standardized mean difference (SMD) = 0.49, 95% confidence interval (CI) 0.18-0.79, p = 0.002), inhibition (SMD = 0.45, 95% CI 0.06-0.84, p = 0.022), working memory (SMD = 0.50, 95% CI 0.18-0.82, p = 0.002), cognitive flexibility (SMD = 0.39, 0.15-0.62, p = 0.002) and vocabulary (SMD = 1.18, 0.19-2.16, p = 0.019). Sensitivity analyses confirmed the benefits in all cases except for inhibition (p = 0.062). No consistent differences were found relating to any moderator variable. CONCLUSIONS: Although further research is warranted, our findings suggest that PA interventions may improve cognitive performance in early childhood, particularly in the domains of attention, inhibition, working memory, cognitive flexibility and vocabulary. These findings might support the implementation of PA interventions from early childhood. PROSPERO REGISTRATION: CRD42021249319.

Supervised Versus Unsupervised Exercise for the Improvement of Physical Function and Well-Being Outcomes in Older Adults: A Systematic Review and Meta-analysis of Randomized Controlled Trials.

BACKGROUND: Unsupervised exercise intervention (UNSUP) appears to be a practical and beneficial strategy for older adults, although its feasibility and effectiveness compared to supervised exercise intervention (SUP) remains unknown. We aimed to compare the safety, attendance/adherence rates, and effectiveness of SUP versus UNSUP on physical function and well-being outcomes in older adults. METHODS: A systematic search was conducted in PubMed, Web of Science, CINAHL, SPORTDiscus, and APA PsycINFO up to September 2022 for randomized controlled trials comparing SUP versus UNSUP in older adults (≥ 60 years). Safety and attendance/adherence rates were registered as indicators of feasibility, and meta-analyses were performed for physical function and well-being outcomes. Sub-analyses were performed for those studies that applied a similar intervention in both groups and for those studies where participants performed ≥ 66% of the sessions in the assigned condition. RESULTS: Thirty-four studies were included (n = 2830). No serious adverse events were reported, with similar attendance rates (81%) for both SUP and UNSUP. Compared with UNSUP, SUP induced significant higher benefits on knee extension strength (standardized mean difference (SMD) = 0.18, p = 0.002), sit-to-stand test (STS, SMD = 0.25, p = 0.050), timed-up-and-go test (TUG, SMD = 0.21, p = 0.035), usual gait speed (SMD = 0.29, p = 0.026), lean mass (mean difference = 1.05 kg, p < 0.001) and health-related quality of life (HRQoL, SMD = 0.21, p = 0.035), albeit only knee extension strength remained significant in sensitivity analyses. Sub-analyses revealed superior benefits of SUP on knee extension strength when only considering those studies that applied a similar intervention in both SUP and UNSUP groups. However, no significant benefits were found for the remaining outcomes. Beneficial effects of SUP over UNSUP were also observed for knee extension strength, STS, functional reach test, TUG, usual gait speed, lean mass, and HRQoL when separately analyzing those studies in which participants performed ≥ 66% of the sessions in the assigned condition. CONCLUSIONS: Current evidence suggests that both SUP and UNSUP programs are safe and could exert benefits on physical function and HRQoL. However, despite being associated with similar attendance rates, SUP might offer some additional benefits, although further high-quality research (i.e., accounting for confounding factors such as presence of supervised sessions in UNSUP or vice versa, as well as equating the exercise dose) is necessary to confirm these findings. PROSPERO REGISTRATION NUMBER: CRD42022326420.

High-dose short-term creatine supplementation without beneficial effects in professional cyclists: a randomized controlled trial.

BACKGROUND: Growing evidence supports the ergogenic effects of creatine supplementation on muscle power/strength, but its effects on endurance performance remain unclear. We assessed the effects of high-dose short-term creatine supplementation in professional cyclists during a training camp. METHODS: The study followed a double-blind, randomized parallel design. Twenty-three professional U23 cyclists (19 ± 1 years, maximum oxygen uptake: 73.0 ± 4.6 mL/kg/min) participated in a 6-day training camp. Participants were randomized to consume daily either a recovery drink (containing carbohydrates and protein) with a 20-g creatine supplement (creatine group, n = 11) or just the recovery drink (placebo group, n = 12). Training loads and dietary intake were monitored, and indicators of fatigue/recovery (Hooper index, countermovement jump height), body composition, and performance (10-second sprint, 3-, 6-, and 12-minute time trials, respectively, as well as critical power and W') were assessed as study outcomes. RESULTS: The training camp resulted in a significant (p < 0.001) increase of training loads (+50% for total training time and + 61% for training stress score, compared with the preceding month) that in turn induced an increase in fatigue indicators (significant time effect [p < 0.001] for delayed-onset muscle soreness, fatigue, and total Hooper index) and a decrease in performance (significant time effect [p = 0.020] for critical power, which decreased by -3.8%). However, no significant group-by-time interaction effect was found for any of the study outcomes (all p > 0.05). CONCLUSIONS: High-dose short-term creatine supplementation seems to exert no consistent beneficial effects on recovery, body composition or performance indicators during a strenuous training period in professional cyclists.

Physical exercise: a polypill against chronic kidney disease.

We are currently facing a pandemic of physical inactivity that might contribute to the growing prevalence of chronic kidney disease (CKD). Here, we summarize currently available evidence on the association between physical activity and CKD, and also review the effects of exercise intervention in affected patients. Physical activity/exercise might act as a polypill against CKD, preventing its development or even exerting beneficial effects once it is established (i.e. improvements in patients' physical fitness and cardiovascular risk, as well as in kidney function). Exercise benefits are also found at advanced CKD stages or in patients under hemodialysis. The biological mechanisms behind the clinical evidence are also discussed. An active lifestyle appears as a cornerstone in CKD prevention and management.

Torque-Cadence Profile and Maximal Dynamic Force in Cyclists: A Novel Approach.

We aimed to determine the feasibility, test-retest reliability and long-term stability of a novel method for assessing the force (torque)-velocity (cadence) profile and maximal dynamic force (MDF) during leg-pedaling using a friction-loaded isoinertial cycle ergometer and a high-precision power-meter device. Fifty-two trained male cyclists completed a progressive loading test up to the one-repetition maximum (1RM) on a cycle ergometer. The MDF was defined as the force attained at the cycle performed with the 1RM-load. To examine the test-retest reliability and long-term stability of torque-cadence values, the progressive test was repeated after 72 h and also after 10 weeks of aerobic and strength training. The participants' MDF averaged 13.4 ± 1.3 N·kg-1, which was attained with an average pedal cadence of 21 ± 3 rpm. Participants' highest power output value was attained with a cadence of 110 ± 16 rpm (52 ± 5% MDF). The relationship between the MDF and cadence proved to be very strong (R2 = 0.978) and independent of the cyclists' MDF (p = 0.66). Cadence values derived from this relationship revealed a very high test-retest repeatability (mean SEM = 4 rpm, 3.3%) and long-term stability (SEM = 3 rpm, 2.3%); despite increases in the MDF following the 10-week period. Our findings support the validity, reliability and long-term stability of this method for the assessment of the torque-cadence profile and MDF in cyclists.

The role of supervision and motivation during exercise on physical and mental health in older adults: a study protocol for a randomized controlled trial (PRO-Training project).

BACKGROUND: Although supervised exercise is frequently recommended for older adults, its superiority over unsupervised exercise remains uncertain. Furthermore, whether motivational techniques could help to enhance the effectiveness of the latter remains to be elucidated. The present randomized controlled trial aims to determine the role of supervision and motivational strategies on the safety, adherence, efficacy, and cost-effectiveness of different exercise programs for improving physical and mental health in older adults. METHODS: Participants (n = 120, aged 60-75 years) will be randomly allocated into five groups: 1-Control (CON), 2-Supervised exercise without motivational intervention (SUP), 3- Supervised exercise with motivational intervention (SUP +), 4- Unsupervised exercise without motivational intervention (UNSUP) and 5- Unsupervised exercise with motivational intervention (UNSUP +). Over 24 weeks, all exercise groups will participate in a multicomponent exercise program three times/week (performed in group classes at a center for SUP and SUP + , or home without supervision but with the help of a mobile app for UNSUP and UNSUP +), while the CON group will maintain their usual lifestyle. The motivational intervention (for SUP + and UNSUP + groups) will be based on the self-determination theory, including strategies such as phone calls, interactive workshops, motivational messages, informative infographics and videos. Primary outcomes will include safety, adherence, costs, and lower-body muscular function using a leg press machine. Secondary outcomes will include upper-body muscular function, physical and cardiorespiratory function, blood pressure and heart rate, body composition, health-related quality of life, cognitive performance, anxiety, depression, physical activity levels, sleep and sedentarism, biochemical markers, motivators and barriers to exercise. Assessments will be conducted at baseline, mid-intervention (i.e., week 13), at the end of the intervention (i.e., week 25), and 24 weeks later (i.e., week 49). DISCUSSION: The findings of this trial might provide valuable insights into the role of supervision and motivational strategies on the effectiveness of exercise programs for older adults. Additionally, the study could contribute to developing cost-effective interventions, supporting the design of future public policies for healthy aging. TRIAL REGISTRATION: NCT05619250. Registered 16 November 2022.

The Influence of High-Intensity Work on the Record Power Profile of Under-23, Pro Team, and World Tour Cyclists.

BACKGROUND: Durability (ie, the ability to attenuate the decline in performance after accumulated work) has been identified as a performance determinant in elite cyclists. The aim of the present study was to compare durability in elite cyclists of various performance levels, particularly after high-intensity work, referred to as "high-intensity durability." METHODS: Forty-nine (N = 49) male road cyclists were categorized as either under 23 years of age (U23) (N = 11), Pro Team (N = 13), or World Tour (N = 24). The participants' critical power (CP) was assessed during the preseason. Thereafter, the participants' maximum mean power (MMP) values were determined for efforts of different durations (from 5 s to 30 min) after different levels of accumulated work above CP (from 0 to 7.5 kJ·kg-1). RESULTS: U23 cyclists showed a significant reduction of all relative MMP values for durations ≥1 minute after ≥5 kJ·kg-1 above CP compared with the "fresh" state (0 kJ·kg-1), whereas in Pro Team and World Tour cyclists, a significant reduction was not observed until 7.5 kJ·kg-1 above CP. In the "fresh" state, both Pro Team and particularly World Tour cyclists attained higher MMP values for efforts ≥10 minutes than U23 riders. However, more differences emerged with greater previous work levels, and indeed after 7.5 kJ·kg-1 above CP World Tour cyclists attained higher MMP values than both U23 and Pro Team cyclists for most efforts (≥30 s). CONCLUSION: Pro Team and particularly World Tour cyclists tolerate greater levels of accumulated work at high intensity, which might support the importance of high-intensity durability for performance.

Exercise Intervention and Hospital-Associated Disability: A Nonrandomized Controlled Clinical Trial.

Importance: Inpatient exercise interventions may prevent, at least partly, hospital-associated disability (HAD) in older adults, but whether they also confer clinical benefits in the months following discharge is unclear. Objective: To examine the association of exercise and health education with HAD incidence in hospitalized older adults receiving acute hospital care at discharge and 3 months later. Design, Setting, and Participants: This single-center open-label, nonrandomized controlled clinical trial included patients aged 75 years or older seen at an acute care for elders unit at a tertiary public hospital in Madrid, Spain, from May 1, 2018, to June 30, 2022. Interventions: Patients were allocated to an intervention or control group. Both groups received usual care, but the intervention group also performed a supervised multicomponent exercise program (daily strength, balance, and walking exercises along with inspiratory muscle training) during hospitalization and received health education on how to exercise at home and telephone counseling during follow-up. Main Outcomes and Measures: The primary outcome was HAD incidence (determined by the Katz Index of Independence in Activities of Daily Living [hereafter, Katz Index]) at discharge and after 3 months compared with baseline (ie, 2 weeks before admission). Secondary outcomes included HAD incidence determined by the Barthel Index for Activities of Daily Living, ambulatory capacity decline at discharge and follow-up, changes in physical performance at discharge, and incidence of falls, readmissions, and mortality during the follow-up period. Results: The study included 260 patients (134 women [51.5%]; mean [SD] age, 87.4 [4.9] years [range, 75-105 years]; median hospital length of stay, 7 days [IQR, 5-10 days]), of whom 130 received the intervention and 130 were in the control group. Differences in HAD incidence did not reach statistical significance at discharge (odds ratio [OR], 0.62; 95% CI, 0.37-1.05; P = .08) or follow-up (OR, 0.65; 95% CI, 0.36-1.17; P = .15) when using the Katz Index. A lower HAD incidence was observed in the intervention group at discharge (OR, 0.47; 95% CI, 0.27-0.81; P = .01) and at follow-up (OR, 0.36; 95% CI, 0.20-0.66; P = .001) when using the Barthel Index for Activities of Daily Living. The intervention was also associated with a lesser decline in ambulatory capacity (OR, 0.55; 95% CI, 0.32-0.96; P = .03) and improved physical performance at discharge (Cohen d, 0.39; 95% CI, 0.12-0.65; P = .004). No significant associations were observed for readmissions, falls, or mortality. Conclusions and Relevance: In this nonrandomized controlled clinical trial, an exercise and health education intervention was not significantly associated with reduced HAD incidence when measured by the Katz Index. However, the benefits found for several secondary outcomes might support the implementation of in-hospital exercise programs for older patients. Trial Registration: ClinicalTrials.gov Identifier: NCT03604640.

Lifestyle and cardiovascular risk in working young adults: insights from a nationwide Spanish cohort.

INTRODUCTION AND OBJECTIVES: This study aimed to describe the cardiovascular risk profile of working young adults from Spain and its association with lifestyle. METHODS: Participants (18-30 years) were recruited from a nationwide cohort of economically active adults insured by a large occupational risk prevention company, with data obtained from routine medical assessments. The participants were categorized as having an "unhealthy" cardiovascular risk profile based on the presence of prediabetes/diabetes, prehypertension/hypertension, or hypercholesterolemia, or a "healthy" profile if these conditions were completely absent. The association with lifestyle factors (weight, physical activity, sleeping characteristics, alcohol consumption, smoking) was assessed. RESULTS: A total of 78 421 young adults (27±2 years, 36% female) were evaluated at baseline. The "unhealthy" cardiovascular risk profile was prevalent (18%) and inversely associated (OR, 0.64; 95%CI, 0.57-0.80) with an optimal lifestyle (normal weight, regular physical activity, no drinking/smoking, and good sleep). The latter condition was found in only 3.5% of the participants. On the other hand, prospective analyses in 44 776 participants (median follow-up=2 [range 2-5] years) showed that 2.0% transitioned from a "healthy" to an "unhealthy" profile. Being physically active (OR, 0.95; 95%CI, 0.81-0.99) and having a normal weight (OR, 0.61; 95%CI, 0.51-0.70) were associated with a lower likelihood of this transition. No consistent associations were found for other lifestyle factors. CONCLUSIONS: The prevalence of cardiovascular risk factors is high in economically active young Spanish adults. An unhealthy cardiovascular risk profile is inversely associated with an optimal lifestyle, but the latter is highly infrequent in this population.

Acute ketone supplementation in the absence of muscle glycogen utilization: Insights from McArdle disease.

BACKGROUND & AIMS: Ketone supplementation is gaining popularity. Yet, its effects on exercise performance when muscle glycogen cannot be used remain to be determined. McArdle disease can provide insight into this question, as these patients are unable to obtain energy from muscle glycogen, presenting a severely impaired physical capacity. We therefore aimed to assess the effects of acute ketone supplementation in the absence of muscle glycogen utilization (McArdle disease). METHODS: In a randomized cross-over design, patients with an inherited block in muscle glycogen breakdown (i.e., McArdle disease, n = 8) and healthy controls (n = 7) underwent a submaximal (constant-load) test that was followed by a maximal ramp test, after the ingestion of a placebo or an exogenous ketone ester supplement (30 g of D-beta hydroxybutyrate/D 1,3 butanediol monoester). Patients were also assessed after carbohydrate (75 g) ingestion, which is currently considered best clinical practice in McArdle disease. RESULTS: Ketone supplementation induced ketosis in all participants (blood [ketones] = 3.7 ± 0.9 mM) and modified some gas-exchange responses (notably increasing respiratory exchange ratio, especially in patients). Patients showed an impaired exercise capacity (-65 % peak power output (PPO) compared to controls, p < 0.001) and ketone supplementation resulted in a further impairment (-11.6 % vs. placebo, p = 0.001), with no effects in controls (p = 0.268). In patients, carbohydrate supplementation resulted in a higher PPO compared to ketones (+21.5 %, p = 0.001) and a similar response was observed vs. placebo (+12.6 %, p = 0.057). CONCLUSIONS: In individuals who cannot utilize muscle glycogen but have a preserved ability to oxidize blood-borne glucose and fat (McArdle disease), acute ketone supplementation impairs exercise capacity, whereas carbohydrate ingestion exerts the opposite, beneficial effect.

Association of physical behaviours with sarcopenia in older adults: a systematic review and meta-analysis of observational studies.

BACKGROUND: Physical behaviours (ie, physical activity and sedentary behaviour) might have a role in the development of sarcopenia, although the evidence is unclear. We aimed to explore the association of total and intensity-specific levels of physical activity and sedentary behaviour with sarcopenia and its components (ie, muscle mass, muscle strength, and physical performance) in older adults. METHODS: We conducted a systematic review and meta-analysis and searched MEDLINE (via PubMed), Scopus, and Web of Science from inception to July 26, 2022, for peer-reviewed, observational studies or baseline data from randomised clinical trials conducted in older adults (ie, individual age ≥60 years or mean age ≥65 years) and published in English that reported on the association of physical activity or sedentary behaviour or both with sarcopenia (or its determinants: muscle mass or strength, and physical performance). Physical activity and sedentary behaviour were measured by any method. The main outcome was sarcopenia, which could be diagnosed by any means. Estimates were extracted and pooled using Bayesian meta-analytic models and publication bias was assessed using the Egger's test. This study is registered with PROSPERO, CRD42022315865. FINDINGS: We identified 15 766 records, of which 124 studies (230 174 older adults; 121 301 [52·7%] were female and 108 873 [47·3%] were male) were included in the systematic review. 86 studies were subsequently included in the meta-analysis. Higher levels of total physical activity were inversely associated with sarcopenia both cross-sectionally (21 studies, n=59 572; odds ratio 0·49, 95% credible interval 0·37-0·62) and longitudinally (four studies, n=7545; 0·51, 0·27-0·94). A protective association was also identified for moderate-to-vigorous physical activity in cross-sectional research (five studies, n=6787; 0·85, 0·71-0·99), whereas no association was identified for the remaining physical behaviours (ie, steps, light physical activity, or sedentary behaviour). INTERPRETATION: Total and moderate-to-vigorous physical activity are inversely associated with sarcopenia. These findings might support the importance of moderate-to-vigorous, rather than light, intensity physical activity-based interventions to prevent sarcopenia. FUNDING: None. TRANSLATION: For the Spanish translation of the abstract see Supplementary Materials section.

Physical activity, chronic kidney disease, and cardiovascular risk: A study in half a million adults.

OBJECTIVE: There is a growing prevalence of chronic kidney disease (CKD), a condition associated with a higher cardiovascular disease (CVD) risk. We assessed the association between self-reported physical activity (PA) and CKD and also studied whether PA attenuates CKD-associated CVD risk. METHODS: A cohort of Spanish adults (18-64 years) participated in this nationwide study. Participants were categorized at baseline as being either inactive (performing no PA), regularly, or insufficiently active (meeting or not, respectively, international PA recommendations) and were followed for up to 5 years. The presence of CKD (estimated glomerular filtration rate <60 mL/min/1.73 m2 ) and major CVD risk factors (diabetes, hypercholesterolemia, hypertension, obesity) was determined at baseline and at follow-up. RESULTS: 517 917 participants (44 ± 9 years, 67% male, CKD prevalence = 7%) were studied at baseline, with prospective analyses (median follow-up = 2 years, range = 2-5) in a subcohort of 264 581 individuals. Compared to physical inactivity, cross-sectional analyses at baseline showed that regular PA (odds ratio = 0.80; 95% confidence interval = 0.79-0.81), but not insufficient PA (1.02; 0.99-1.04) was associated with lower CKD prevalence. However, prospective analyses failed to confirm this association (p > 0.1). In turn, CKD was associated with a higher prevalence of hypertension (+3%) and diabetes (+5%) at baseline and with a greater incidence of hypertension at follow-up (+37%). Among those participants with CKD, regular PA was associated with a lower prevalence (-45% to -7%) and incidence (-38% to -4%) of all CVD risk factors. CONCLUSION: Although PA might not reduce incident CKD in the middle term (~2 years), it can attenuate the CVD risk linked to this condition.

The Tour de France, also possible for mortals? A comparison of a recreational and a World Tour cyclist.

Cycling Grand Tours are arguably the epitome of strenuous endurance exercise, and they have been reported to represent the ceiling of sustained energy expenditure for humans. It remains unknown, however, if an average recreational athlete could endure such an event. Through the analysis of power output (PO), we compared data from the 2023 Tour de France (21 stages, total distance = 3,405 km, elevation gain = 51,815 m) in a recreational (male, age = 58 yr; height = 191 cm; body mass = 96.1 kg; estimated maximum oxygen uptake = 45.4 mL·kg-1·min-1) and a sex-matched professional (World-Tour) cyclist (28 yr; 180 cm; 67.0 kg; 80.5 mL·kg-1·min-1). The recreational and professional cyclist completed the event in 191 and 87 h, respectively (average PO of 1.50 and 3.45 W·kg-1), with the latter spending a greater proportion of time in high-intensity zones. The recreational cyclist showed an estimated total daily energy expenditure (TDEE) of 35.9 MJ [or 8,580 kcal, or ∼4.3× his daily basal metabolic rate (BMR)], whereas lower absolute values were estimated for the professional cyclist (29.7 MJ, 7,098 kcal, ∼3.8× his BMR). Despite such high TDEE values, both individuals lost minimal body mass during the event (0-2 kg). The present report therefore suggests that, partly due to differences in exercise intensity and duration, not only professional cyclists but also recreational athletes can reach currently known ceilings of TDEE for humans.NEW & NOTEWORTHY This case report indicates that a recreationally trained 58-year-old man can reach similar or even higher values of energy expenditure (∼4 times their basal metabolic rate) than professional cyclists, who are likely near the ceiling of sustained energy expenditure for humans. This was possible owing to a total longer exercise time coupled with a lower absolute and relative intensity in the recreational athlete.

The effect of physical exercise on anticancer immunity.

Regular physical activity is associated with lower cancer incidence and mortality, as well as with a lower rate of tumour recurrence. The epidemiological evidence is supported by preclinical studies in animal models showing that regular exercise delays the progression of cancer, including highly aggressive malignancies. Although the mechanisms underlying the antitumorigenic effects of exercise remain to be defined, an improvement in cancer immunosurveillance is likely important, with different immune cell subtypes stimulated by exercise to infiltrate tumours. There is also evidence that immune cells from blood collected after an exercise bout could be used as adoptive cell therapy for cancer. In this Perspective, we address the importance of muscular activity for maintaining a healthy immune system and discuss the effects of a single bout of exercise (that is, 'acute' exercise) and those of 'regular' exercise (that is, repeated bouts) on anticancer immunity, including tumour infiltrates. We also address the postulated mechanisms and the clinical implications of this emerging area of research.

Time-course Changes of Field- and Laboratory-based Performance Indicators in Junior Cyclists Through a Season.

This study aimed to assess the seasonal evolution of field-based and laboratory-based performance indicators in cyclists. Thirteen Junior male road cyclists (age 17.4±0.5 years) were followed up during a season, which was divided in three phases: early season (involving mainly training sessions), mid-season (including the first competitions), and late season (including the major competitions of the season). During each phase, field-based power output data were registered for the assessment of maximum mean power values, and laboratory-based endurance (ramp test and simulated 8-minute time trial), muscle strength/power (squat, lunge, hip thrust) and body composition indicators (dual-energy X-ray absorptiometry) were also assessed. A progressive (p<0.01) increase in maximum mean power values (e.g., 3.8±0.3 and 4.5±0.4 watts/kg in early and late season, respectively, for 60-minute efforts) and on 8-minute time trial performance (i.e., 5.3±0.3 and 5.6±0.4 watts/kg, respectively) was observed through the season. Yet, more "traditional" endurance indicators (i.e., ventilatory threshold, respiratory compensation point, or maximum oxygen uptake) seemed to show a ceiling effect beyond the mid-season. In addition, neither peak power output, body composition, nor muscle strength indicators followed a similar pattern to the aforementioned field-based indicators. In summary, in Junior cyclists field-based indicators seem more sensitive to monitor endurance cyclists' changes in actual fitness and performance capacity than more "traditional" laboratory-based markers in Junior cyclists.