Effects of different sprint training programs with ball on explosive, high-intensity and endurance-intensive performances in male young soccer players

This study compared the effects of different sprint ball-based training programs on fitness-related performances in youth soccer players. Forty male players (age: 15.2 ± 0.6 yrs) participated in a short-term (8 weeks) randomized parallel fully controlled training study, with pre-to-post measurements. Players were randomly assigned to 3 sprint ball-based training groups: training with combined sprint (performing linear and change of direction sprints; CST), or using linear sprint (LST), or performing sprint with change of direction (CODT) and to a control group (CONT). Pre- and post-training players completed a test battery involving linear sprinting (10 and 20 m, and flying 10 m), 505 test (COD), 15 m test with ball (CODB), countermovement jump test (CMJ test) and maximal oxygen consumption (VO2max). All physical performance’ variables improved after the training intervention (all p < 0.05; ES ≥ 0.2). No main effect of groups was observed in linear sprinting, CMJ and VO2max (p > 0.05; ES < 0.2). A training group main effect was found (p < 0.0001; ES = 0.50) for COD with CODT induced better performance than LST and CONT (all p <0.0001; ES > 0.8). Also, a training group main effect (p = 0.009; ES = 0.35) was found for CODB with CODT elicited better performance than LST and CONT (all p = 0.001; ES > 0.80). Our findings suggest that ball-based training programs were more effective to improve fitness levels in youth players during the in-season period and that CODT modality was more effective to improve COD and CODB performances.

Alternative Metabolic Strategies are Employed by Endurance Runners of Different Body Sizes; Implications for Human Evolution

Objective A suite of adaptations facilitating endurance running (ER) evolved within the hominin lineage. This may have improved our ability to reach scavenging sites before competitors, or to hunt prey over long distances. Running economy (RE) is a key determinant of endurance running performance, and depends largely on the magnitude of force required to support body mass. However, numerous environmental factors influence body mass, thereby significantly affecting RE. This study tested the hypothesis that alternative metabolic strategies may have emerged to enable ER in individuals with larger body mass and poor RE. Methods A cohort of male (n = 25) and female (n = 19) ultra-endurance runners completed submaximal and exhaustive treadmill protocols to determine RE, and V̇O2Max. Results Body mass was positively associated with sub-maximal oxygen consumption at both LT1 (male r=0.66, p<0.001; female LT1 r=0.23, p=0.177) and LT2 (male r=0.59, p=0.001; female r=0.23, p=0.183) and also with V̇O2Max (male r=0.60, p=0.001; female r=0.41, p=0.046). Additionally, sub-maximal oxygen consumption varied positively with V̇O2Max in both male (LT1 r=0.54, p=0.003; LT2 r=0.77, p<0.001) and female athletes (LT1 r=0.88, p<0.001; LT2 r=0.92, p<0.001). Conclusions The results suggest that, while individuals with low mass and good RE can glide economically as they run, larger individuals can compensate for the negative effects their mass has on RE by increasing their capacity to consume oxygen. The elevated energy expenditure of this low-economy high-energy turnover approach to ER may bring costs associated with energy diversion away from other physiological processes, however.

Prevalence of Long COVID symptoms in Bangladesh: a prospective Inception Cohort Study of COVID-19 survivors

BackgroundThe objective of this study was to identify the prevalence of long COVID symptoms in a large cohort of people living with and affected by long COVID and identify any potential associated risk factors.MethodsA prospective survey was undertaken of an inception cohort of confirmed people living with and affected by long COVID (aged 18–87 years). 14392 participants were recruited from 24 testing facilities across Bangladesh between June and November 2020. All participants had a previously confirmed positive COVID-19 diagnosis, and reported persistent symptoms and difficulties in performing daily activities. Participants who consented were contacted by face-to-face interview, and were interviewed regarding long COVID, and restriction of activities of daily living using post COVID-19 functional status scale. Cardiorespiratory parameters measured at rest (heart rate, systolic blood pressure, diastolic blood pressure, oxygen saturation levels, maximal oxygen consumption, inspiratory and expiratory lung volume) were also measured.ResultsAmong 2198 participants, the prevalence of long COVID symptoms at 12 weeks was 16.1%. Overall, eight long COVID symptoms were identified and in descending order of prominence are: fatigue, pain, dyspnoea, cough, anosmia, appetite loss, headache and chest pain. People living with and affected by long COVID experienced between 1 and 8 long COVID symptoms with an overall duration period of 21.8±5.2 weeks. Structural equation modelling predicted the length of long COVID to be related to younger age, female gender, rural residence, prior functional limitation and smoking.ConclusionIn this cohort, at 31 weeks post diagnosis, the prevalence of long COVID symptoms was 16.1%. The risk factors identified for presence and longer length of long COVID symptoms warrant further research and consideration to support public health initiatives.

Impacts of different intensities of exercise on inflammation and hypoxia markers in low altitude

Background This study aims to determine and compare the effects of exercise modalities with different intensities on the secretion of key inflammation and hypoxia markers in amateur athletes. Methods Twenty-three athletes with a mean age of 20.1 years, living at low altitude (1850 m) participated in this study. The participants' maximal oxygen consumption values (VO2 max) were determined with an incremental cycle exercise test as 54.15 ± 6.14 mL kg min−1. Athletes performed four protocols: at rest, 50% VO2 max, 75% VO2 max and 100% VO2 max (until exhaustion) with one-week intervals. 50% VO2 max, 75% VO2 max sessions were performed continuously for 30 min on a bicycle ergometer and 100% VO2 max session was performed by cycling until exhaustion. Blood samples were obtained at rest and immediately after each exercise session. Serum tumor necrosis factor alpha (TNF-α), C-reactive protein (CRP), interleukin-10 (IL-10), and hypoxia inducible factor-1 alpha (HIF-1α) levels were measured. Results There were significant differences in serum TNF-α levels in 75% VO2 max and 100% VO2 max sessions (489.03 ± 368.37 and 472.70 ± 365.21 ng/L, respectively) compared to rest conditions (331.65 ± 293.52 ng/L). Serum CRP levels of 50% VO2 max and 75% VO2 max sessions (1.19 ± 0.50; 1.07 ± 0.52 mg/L) were significantly higher than the rest condition (0.74 ± 0.35 mg/L). There were significant differences in serum IL-10 levels of rest condition and 50% VO2 max; 50% VO2 max, and 100% VO2 max sessions (328.09 ± 128.87; 446.36 ± 142.84; 347.44 ± 135.69; 324.88 ± 168.06 pg/mL). Serum HIF-1α levels were significantly higher in 75% VO2 max session compared to rest (1.26 ± 0.16; 1.08 ± 0.19 ng/mL) (P < 0.05 for all comparisons). Conclusions Both inflammatory and anti-inflammatory pathway is induced on different exercise intensities. Exercise protocols performed until exhaustion may lead to activation of inflammatory pathways and hypoxia-induced damage.

Performance Profile among Age Categories in Young Cyclists

Endurance profile assessment is of major interest to evaluate the cyclist’s performance potential. In this regard, maximal oxygen uptake and functional threshold power are useful functional parameters to determine metabolic training zones (ventilatory threshold). The aim of this study was to evaluate and compare the physiological profile of different road cyclist age categories (Youth, Junior, and Under-23) to obtain the performance requirements. Sixty-one competitive road cyclists (15–22 years) performed a maximal incremental test on a bike in order to determine functional parameters (maximal fat oxidation zone, ventilatory thresholds, maximal oxygen uptake, and functional threshold power) and metabolic training zones. The results suggest major differences, with the Youth group showing clear changes in all metabolic zones except in fat oxidation. The main differences between Under-23 vs. Junior groups were observed in maximal relative power output (Under-23: 6.70 W·Kg−1; Junior: 6.17 W·Kg−1) and relative functional threshold power (Under-23: 4.91 W·Kg−1; Junior: 4.48 W·Kg−1). The Youth group physiological profile is clearly different to the other age categories. Some parameters normalized to body weight (maximal oxygen consumption, load and functional threshold power) could be interesting to predict a sporting career during the Junior and Under-23 stages.

Association of Plasma Carotenoid and Malondialdehyde Levels with Physical Performance in Korean Adolescents

Background Increased oxidative stress has been shown to lead to muscle damage and reduced physical performance. The antioxidant mechanism is most likely to reduce these relationships, but in the context of the action of carotenoids, more research is needed. This cross-sectional study aims to investigate whether carotenoids modify the association between plasma malondialdehyde (MDA) and physical performance in Korean adolescents. Methods The study sample consisted of 381 participants (164 boys, 217 girls) aged 13−18, who participated in the 2018 National Fitness Award Project. We quantified α-carotene, β-carotene, β-cryptoxanthin, lutein, zeaxanthin, lycopene, and MDA levels in plasma using HPLC with photodiode array detection. Physical performance was measured by determining the absolute and relative hand grip strength, 20-m progressive aerobic cardiovascular endurance run, estimated maximal oxygen consumption, curl-up, and sit-and-reach. Results In boys, the multiple linear regression model adjusted for age, BMI, smoking, drinking, and physical activity showed that the MDA level was negatively associated with absolute hand grip strength; this association was observed only in groups with α-carotene, β-cryptoxanthin, zeaxanthin, and total carotenoid values below the median. Conclusion These results suggest that carotenoids may act as an effect modifier of the association between MDA and physical performance in Korean male adolescents.

Moderately trained male football players, compared to sedentary male adults, exhibit anatomical but not functional cardiac remodelling, a cross-sectional study

Background Elite athletes have been the subject of great interest, but athletes at an intermediate level of physical activity have received less attention in respect to the presence of cardiac enlargement and/or hypertrophy. We hypothesized that playing football, often defined as demanding less endurance components than running or cycling, would still induce remodelling similar to sports with a dominating endurance component. Methods 23 male football players, age 25+/− 3.9 yrs. underwent exercise testing, 2D- and 3D- echocardiography and cardiac magnetic resonance (CMR). The results were compared with a control group of engineering students of similar age. The athletes exercised 12 h/week and the control subjects 1 h/week, p < 0.001. Results The football players achieved a significantly higher maximal load at the exercise test (380 W vs 300 W, p < 0.001) as well as higher calculated maximal oxygen consumption, (49.7 vs 37.4 mL x kg− 1 x min− 1, p < 0.001) compared to the sedentary group. All left ventricular (LV) volumes assessed by 3DEcho and CMR, as well as CMR left atrial (LA) volume were significantly higher in the athletes (3D-LVEDV 200 vs 154 mL, CMR-LVEDV 229 vs 185 mL, CMR-LA volume 100 vs 89 mL, p < 0.001, p = 0.002 and p = 0.009 respectively). LVEF and RVEF, LV strain by CMR or by echo did not differentiate athletes from sedentary participants. Right ventricular (RV) longitudinal strain, LA and right atrial (RA) strain by CMR all showed similar results in the two groups. Conclusion Moderately trained intermediate level football players showed anatomical but not functional cardiac remodelling compared to sedentary males.

Increased Reliance on Carbohydrates for Aerobic Exercise in Highland Andean Leaf-Eared Mice, but Not in Highland Lima Leaf-Eared Mice

Exercise is an important performance trait in mammals and variation in aerobic capacity and/or substrate allocation during submaximal exercise may be important for survival at high altitude. Comparisons between lowland and highland populations is a fruitful approach to understanding the mechanisms for altitude differences in exercise performance. However, it has only been applied in very few highland species. The leaf-eared mice (LEM, genus Phyllotis) of South America are a promising taxon to uncover the pervasiveness of hypoxia tolerance mechanisms. Here we use lowland and highland populations of Andean and Lima LEM (P. andium and P. limatus), acclimated to common laboratory conditions, to determine exercise-induced maximal oxygen consumption (V˙O2max), and submaximal exercise metabolism. Lowland and highland populations of both species showed no difference in V˙O2max running in either normoxia or hypoxia. When run at 75% of V˙O2max, highland Andean LEM had a greater reliance on carbohydrate oxidation to power exercise. In contrast, highland Lima LEM showed no difference in exercise fuel use compared to their lowland counterparts. The higher carbohydrate oxidation seen in highland Andean LEM was not explained by maximal activities of glycolytic enzymes in the gastrocnemius muscle, which were equivalent to lowlanders. This result is consistent with data on highland deer mouse populations and suggests changes in metabolic regulation may explain altitude differences in exercise performance.

FRI-1 Is an Anti-Cancer Isoquinolinequinone That Inhibits the Mitochondrial Bioenergetics and Blocks Metabolic Shifts by Redox Disruption in Breast Cancer Cells

Since breast cancer (BC) cells are dependent on mitochondrial bioenergetics for promoting proliferation, survival, and metastasis, mitochondria highlight as an important target for anticancer drug discovery. FRI-1, methyl 1, 3-dimethyl-5, 8-dioxo-5, 8-dihydro-4-isoquinolinecarboxylate, was previously described as a selective cytotoxic compound on cancer cell lines, however, details on the mechanism of action remain unknown. In this work, we describe that FRI-1 inhibits mitochondrial bioenergetics, producing apoptosis in MCF7 and MDA-MB-231 BC cell lines. FRI-1 decreases the maximal oxygen consumption rate (OCR), Δψm, NADH, and ATP levels, with a notable increase of mitochondrial reactive oxygen species (ROS) production, promoting AMPK activation with pro-survival effects. Moreover, FRI-1 inhibits the metabolic remodeling to glycolysis induced by oligomycin. In isolated tumoral mitochondria, FRI-1 increases Complex I and III-dependent OCR state 2, and this is sensitive to rotenone and antimycin A inhibitor additions, suggesting a redox cycling event. Remarkably, α-ketoglutarate and lipoic acid supplementation reversed and promoted, respectively, the FRI-1-induced apoptosis, suggesting that mitochondrial redox disruption affects 2-oxoglutarate dehydrogenase (OGDH) activity, and this is involved in their anticancer mechanism. Consistent with this, the combination of FRI-1 and CPI-613, a dual inhibitor of redox-sensible tricarboxylic acid (TCA) cycle enzymes PDH and OGDH, produced extensive BC cell death. Taken together, our results suggest that FRI-1 exhibits anticancer effects through inhibition of mitochondrial bioenergetics by redox disruption in BC cells.

Cardiorespiratory Fitness in Occupational Groups—Trends over 20 Years and Future Forecasts

Background: Reports have indicated a negative trend in cardiorespiratory fitness (CRF) in the general population. However, trends in relation to different occupational groups are missing. Therefore, the aim of our study was to examine the trends in CRF during the last 20 years, and to provide a prognosis of future trends in CRF, in different occupational groups of Swedish workers. Methods: Data from 516,122 health profile assessments performed between 2001 to 2020 were included. CRF was assessed as maximal oxygen consumption and was estimated from a submaximal cycling test. Analyses include CRF as a weighted average, standardized proportions with low CRF (<32 mL/min/kg), adjusted annual change in CRF, and forecasting of future trends in CRF. Results: There was a decrease in CRF over the study period, with the largest decrease in both absolute and relative CRF seen for individuals working in administrative and customer service (−10.1% and −9.4%) and mechanical manufacturing (−6.5% and −7.8%) occupations. The greatest annual decrease was seen in transport occupations (−1.62 mL/min/kg, 95% CI −0.190 to −0.134). Men and younger individuals had in generally a more pronounced decrease in CRF. The proportion with a low CRF increased, with the greatest increase noted for blue-collar and low-skilled occupations (range: +16% to +21% relative change). The forecast analyses predicted a continuing downward trend of CRF. Conclusion: CRF has declined in most occupational groups in Sweden over the last two decades, with a more pronounced decline in blue-collar and low-skilled occupational groups.