15 weeks of soccer training increases left ventricular mass and improves indices of left ventricular diastolic function in previously sedentary, mildly hypertensive, middle-aged women

PURPOSE

To investigate the impact of soccer training on cardiac adaptations in mildly hypertensive middle-aged women.

METHODS

Hypertensive premenopausal women (n = 41; age (mean ± SD): 44 ± 7 years; height: 166 ± 6 cm; weight: 78.6 ± 11.6 kg; body fat: 43.3 ± 5.2%) were randomized to soccer training (SOC, n = 21) or control (CON, n = 20). SOC performed three weekly training sessions for 15 weeks, whereas CON had no training or lifestyle changes during the same period. Cardiac structure and function were assessed by echocardiography pre-intervention and post-intervention.

RESULTS

Soccer training increased (P = 0.001) left ventricular mass index by 10% [95% CI 4; 15], while no changes occurred in CON (time × group interaction, P = 0.005). In addition, only SOC demonstrated a within-group increase (P = 0.01) of 8% [95% CI 2; 14] in left ventricular septum diameter. For markers of right ventricular remodelling, a within-group increase (P = 0.02) occurred for tricuspid annulus plane systolic excursion of 8% [95% CI 1; 14] in SOC only. Left atrial diameter index increased (P < 0.001) by 6% [95% CI 3; 10] after SOC, while it was unaffected in CON (time × group interaction, P = 0.02). For makers of diastolic function, SOC demonstrated a within-group increase (P = 0.02) in the average early diastolic mitral annulus velocity of 10% [95% CI 2; 19]. In addition, a reduction (P < 0.001) in mitral valve A velocity of - 19% [95% CI - 29; - 10] was observed following soccer training, which manifested in increased (P < 0.001) mitral valve E/A ratio of 34% [95% CI 16; 53] in SOC. No within-group changes were apparent in CON.

CONCLUSION

In sedentary, mildly hypertensive, middle-aged women, 15 weeks of soccer training increases left ventricular mass and left atrial diameter and improves indices of left ventricular diastolic function.

Exercise training reduces systemic inflammation and improves general health status in female migraineurs: a randomised controlled trail

OBJECTIVES

The objectives of this study were to assess the effect of 8 weeks of moderate-intensity aerobic training on permeability inflammatory indicators of matrix metalloproteinases (MMPs) and specific tissue inhibitors of MMPs in female migraineurs.

METHODS

Female migraineurs (n = 28, age 32 ± 6) were randomised into two groups: migraine with exercise training (EXE + Mig, n = 13) and migraine without exercise training (NON-EXE + Mig, n = 15). Matched healthy women were also recruited as a healthy control group (CON, n = 15). The EXE-Mig group performed 8 weeks of aerobic training. Pre and post intervention, serum matrix metalloproteinases (MMP-2 and 9) and specific tissue inhibitors of MMPs (TIMP-1 and 2) were measured. In addition, body composition indices and VO2max were determined.

RESULTS

Exercise training reduced serum MMP-9 in female migraineurs with between-group changes and a time x group interaction (p < 0.05). In addition, exercise training reduced the serum MMP-9/TIMP-1 ratio in female migraineurs with between-group changes and time x group interaction (p < 0.05). However, no training-induced effect was observed in serum TIMP-1, TIMP-2, MMP-2 contents (p > 0.05) and MMP-2/TIMP-2 ratio (p > 0.05). Finally, exercise training reduced body fat content, WHR and BMI, and improved VO2max (p < 0.01).

CONCLUSIONS

Our results demonstrated beneficial effects of aerobic exercise training on some circulatory inflammation factors (MMP9, MMP-9/TIMP-1) and some health indicators in female migraineurs, suggesting that such training can be employed as a non-pharmacological therapeutic method.

Acute and subacute effects of strenuous exercise on platelet aggregation, coagulation and fibrinolysis in patients with stable coronary artery disease

INTRODUCTION

Strenuous exercise may occasionally cause coronary thrombosis with myocardial infarction and sudden cardiac death.

MATERIALS AND METHODS

Patients with stable coronary artery disease (CAD) (n = 164) and healthy individuals (n = 25) performed strenuous exercise on a bicycle ergometer. Blood was drawn at baseline, immediately after exercise and 2 h later. Platelet aggregation was measured with Multiplate® Analyzer. Thrombin generation was determined using a thrombogram and by measuring prothrombin fragment 1 + 2 (F1 + 2). A clot lysis assay was used to investigate fibrinolysis.

RESULTS

From baseline to immediately after exercise, thrombin receptor activating peptide (TRAP)-induced platelet aggregation increased in CAD patients (Δ77 AU × min, 95 % confidence interval (CI): 46;107) and in healthy individuals (Δ153 AU × min, 95%CI: 75;232). Endogenous thrombin potential (ETP) was unaffected by exercise, whilst F1 + 2 increased (Δ17%, 95%CI: 11;24) in CAD patients. Fibrin clot lysis time increased by 9 % (95%CI: 1-17) in CAD patients and by 26 % (95%CI: 8;45) in healthy individuals. When comparing baseline to 2 h post-exercise, TRAP-induced platelet aggregation remained slightly elevated in both CAD patients (Δ53 AU × min, 95%CI: 22;84) and healthy individuals (Δ140 AU × min, 95%CI: 62;219). In contrast, ETP and F1 + 2 decreased in CAD patients (Δ-6 %, 95%CI: -10;-1 and Δ-8 %, 95%CI: -14;-2). Moreover, clot lysis time decreased (Δ-19 %, 95%CI: -27;-11) in patients with CAD and returned to baseline in healthy individuals. All p-values were <0.05.

CONCLUSIONS

Platelet aggregation and F1 + 2 were substantially elevated immediately after exercise in CAD patients, indicating a pro-thrombotic state. After 2 h of recovery, they exhibited a markedly increase in fibrinolysis. Similar results were observed in healthy individuals.

An 8-week injury prevention exercise program combined with change-of-direction technique training limits movement patterns associated with anterior cruciate ligament injury risk

Knee ligament sprains are common during change-of-direction (COD) maneuvers in multidirectional team sports. This study aimed to compare the effects of an 8-week injury prevention exercise program containing COD-specific exercises and a similar program containing linear sprint exercises on injury- and performance-related variables during a 135° COD task. We hypothesized that the COD-specific training would lead to (H1) stronger reductions in biomechanical variables associated with anterior cruciate ligament (ACL) injury risk during COD, i.e. knee abduction moment and angle, hip internal rotation angle and lateral trunk lean, and (H2) more effective improvements in COD performance according to the COD completion time, executed angle, ground contact time, and approach speed. Twenty-two sports science students (40% female) completed biomechanical assessments of COD movement strategies before and after participating in two supervised 25-min training sessions per week over 8 weeks. We observed significant 'training x group' interaction effects in support of H1: the COD-specific training but not the linear sprint training led to reduced peak knee abduction moments (interaction, p = 0.027), initial knee abduction (interaction, p < 0.001), and initial lateral trunk lean angles (interaction, p < 0.001) compared to baseline. Although the COD-specific training resulted in sharper executed angles (interaction, p < 0.001), the sprint-specific training group showed reduced COD completion (interaction, p = 0.037) and ground contact times (interaction, p < 0.001). In conclusion, a combination of generic and COD-specific injury prevention training resulted in COD technique adaptations that can help to avoid ACL injury-prone COD movements but may negatively affect COD speed.

Recovery During Successive 120-min Football Games: Results from the 120-min Placebo/Carbohydrate Randomized Controlled Trial

PURPOSE

To examine the recovery kinetics (i.e. time-dependent changes) of performance-related variables between two 120-min male football games performed three days apart with and without carbohydrate (CHO) supplementation.

METHODS

20 male players (20 ± 1 years; body fat: 14.9 ± 5.1%; VO2max: 59.4 ± 3.7 mL•kg-1•min-1) participated in two 120-min football games (G1, G2) according to a randomized, two-trial, repeated measures, cross-over, double-blind design. Participants received carbohydrate/Placebo supplements during recovery between games. Field activity was monitored during the games. Performance testing and blood sampling were performed before, at 90- and 120-min of each game. Muscle biopsies were collected at baseline, 90- and 120-min of G1 and pre-G2.

RESULTS

Compared to G1, G2 was associated with reduced total distance (10,870 vs. 10,685 m during 90-min and 3,327 vs. 3,089 m during extra 30-min; p = 0.007-0.038), average (6.7 vs. 6.2 m•s-1 during extra 30-min match-play; p = 0.007) and maximal speed (32.2 vs. 30.2 m•s-1 during 90-min and 29.0 vs. 27.9 m•s-1 during extra 30-min; p < 0.05), accelerations/decelerations (p < 0.05) and mean HR (p < 0.05). Repeated sprint ability (p < 0.001), jumping (p < 0.05) and strength (p < 0.001) performance were compromised before and during G2. Muscle glycogen was not restored at G2-baseline (p = 0.005). Extended game-play reduced lymphocyte, erythrocyte counts, hematocrit, hemoglobin, reduced glutathione (p < 0.05) and increased DOMS, creatine kinase activity, blood glycerol and ammonia (p < 0.05) and protein carbonyls (p < 0.05) before and during G2. Pax7+ (p = 0.004) and MyoD+ cells (p = 0.019) increased at baseline-G2. Carbohydrate supplementation restored performance and glycogen, reduced glycerol and DOMS responses, and increased leukocyte counts and Pax7+ and MyoD+ cells.

CONCLUSIONS

Results suggest that extended football games induce a prolonged recovery of performance which may be facilitated by carbohydrate supplementation during a congested game fixture.

The physiology of ice hockey performance: An update

Ice hockey is an intense team sport characterized by repeated bursts of fast-paced skating, rapid changes in speed and direction and frequent physical encounters. These are performed in on-ice shifts of ~30-80 s interspersed with longer sequences of passive recovery, resulting in about 15-25 min on-ice time per player. Nearly 50% of the distance is covered at high-intensity skating speeds and with an accentuated intense activity pattern in forwards compared to defensemen. During ice hockey match-play, both aerobic and anaerobic energy systems are significantly challenged, with the heart rate increasing toward maximum levels during each shift, and with great reliance on both glycolytic and phosphagen ATP provision. The high-intensity activity pattern favors muscle glycogen as fuel, leading to pronounced reductions despite the relatively brief playing time, including severe depletion of a substantial proportion of individual fast- and slow-twitch fibers. Player-tracking suggests that the ability to perform high-intensity skating is compromised in the final stages of a game, which is supported by post-game reductions in repeated-sprint ability. Muscle glycogen degradation, in particular in individual fibers, as well as potential dehydration and hyperthermia, may be prime candidates implicated in exacerbated fatigue during the final stages of a game, whereas multiple factors likely interact to impair exercise tolerance during each shift. This includes pronounced PCr degradation, with potential inadequate resynthesis in a proportion of fast-twitch fibers in situations of repeated intense actions. Finally, the recovery pattern is inadequately described, but seems less long-lasting than in other team sports.

Enhancing match official performance: a forward-thinking approach for football evolution

The future of football demands more from players and referees due to heightened match intensity and frequency. To optimize performance and health, collaboration among sport scientists, coaches, and medical staff is crucial. However, match officials often lack the same support as elite players, hindering their development. Granting professional status to referees, implementing evidence-based training, and adopting gender-inclusive methods are vital. Coping with future challenges requires better career support and economic conditions for officials, along with research to enhance their performance and health.

Long-term continuous exercise training counteracts the negative impact of the menopause transition on cardiometabolic health in hypertensive women - a 9-year RCT follow-up

PURPOSE

The study examined effects of 9-yrs of multicomponent exercise training during the menopause interval on cardiometabolic health in hypertensive women.

METHODS

Sedentary, middle-aged women (n = 25) with mild-to-moderate arterial hypertension were randomized into a soccer training (multicomponent exercise; EX; n = 12) or control group (CON; n = 13). EX took part in 1-h football training sessions, 1-3 times weekly, for a consecutive 9-years, totaling ∼800 training sessions, while CON did not take part in regular exercise training. 22 participants entered menopause during the intervention.

RESULTS

A time×group interaction effect (P = 0.04) of 8.5 mmHg in favour of EX was observed for changes in mean arterial pressure (MAP) (EX: -4.8 [-10.7;1.1] mmHg, CON +3.7 [-2.0;9.3] mmHg). Time×group interaction effects in favour of EX were also observed for total body weight (4.6 kg, P = 0.008, EX: +0.7 [-1.7;3.0] kg, CON: +5.3 [3.0;7.6] kg, total fat percentage (5.7%-points, P = 0.02; EX (-1.9 [-4.4;0.6] %-points; P = 0.13), CON +3.8 [1.4;6.2] %-points and for total cholesterol (1.2 mmol/l, P = 0.03, EX: -0.5 [-1.0;-0.1] mmol/l, CON: +0.7 [0.2;1.1] mmol/l. EX reduced (P = 0.02) plasma low-density lipoprotein cholesterol by -0.4 [-0.8;-0.1] mmol/l, whereas an increase (P = 0.01) of 0.4 [0.1;0.8] mmol/l occurred in CON (interaction. P < 0.001). A time×group interaction (P = 0.004) existed for changes in exercise capacity in favour of EX. Fasting glucose remained unchanged in EX and increased (P < 0.001) by 0.7 [0.4;1.0] mmol/l in CON (time×group interaction P = 0.02).

CONCLUSION

In conclusion, long-term multicomponent exercise training fully counteracts the detrimental effects of the menopause transition on cardiometabolic health in hypertensive women.

No net utilization of intramuscular lipid droplets during repeated high-intensity intermittent exercise

Intramuscular lipids are stored as subsarcolemmal or intramyofibrillar droplets with potential diverse roles in energy metabolism. We examined intramuscular lipid utilization through transmission electron microscopy during repeated high-intensity intermittent exercise, an aspect that is hitherto unexplored. Seventeen moderately to well-trained males underwent three periods (EX1-EX3) of 10 × 45-s high-intensity cycling [∼100%-120% Wattmax (Wmax)] combined with maximal repeated sprints (∼250%-300% Wmax). M. vastus lateralis biopsies were obtained at baseline, after EX1, and EX3. During the complete exercise session, no net decline in either subsarcolemmal or intermyofibrillar lipid volume density occurred. However, a temporal relationship emerged for subsarcolemmal lipids with an ∼11% increase in droplet size after EX1 (P = 0.024), which reverted to baseline levels after EX3 accompanied by an ∼30% reduction in the numerical density of subsarcolemmal lipid droplets compared with both baseline (P = 0.019) and after EX1 (P = 0.018). Baseline distinctions were demonstrated with an approximately twofold higher intermyofibrillar lipid volume in type 1 versus type 2 fibers (P = 0.008), mediated solely by a higher number rather than the size of lipid droplets (P < 0.001). No fiber-type-specific differences were observed in subsarcolemmal lipid volume although type 2 fibers exhibited ∼17% larger droplets (P = 0.034) but a lower numerical density (main effect; P = 0.010) including 3% less droplets at baseline. Collectively, these findings suggest that intramuscular lipids do not serve as an important substrate during high-intensity intermittent exercise; however, the repeated exercise pattern mediated a temporal remodeling of the subsarcolemmal lipid pool. Furthermore, fiber-type- and compartment-specific differences were found at baseline underscoring the heterogeneity in lipid droplet deposition.NEW & NOTEWORTHY Undertaking a severe repeated high-intensity intermittent exercise protocol led to no net decline in neither subsarcolemmal nor intermyofibrillar lipid content in the thigh muscle of young moderately to well-trained participants. However, a temporal remodeling of the subsarcolemmal pool of lipid droplets did occur indicative of potential transient lipid accumulation. Moreover, baseline fiber-type distinctions in subcellular lipid droplet deposition were present underscoring the diversity in lipid droplet storage among fiber types and subcellular regions.

The recovery of muscle function and glycogen levels following game-play in young elite male ice hockey players

Despite the frequent occurrence of congested game fixtures in elite ice hockey, the postgame recovery pattern has not previously been investigated. The purpose of the present study was therefore to evaluate the acute decrements and subsequent recovery of skeletal muscle glycogen levels, muscle function and repeated-sprint ability following ice hockey game-play. Sixteen male players from the Danish U20 national team completed a training game with muscle biopsies obtained before, postgame and following ~38 h of recovery (day 2). On-ice repeated-sprint ability and muscle function (maximal voluntary isometric [MVIC] and electrically induced low- (20 Hz) and high-frequency (50 Hz) knee-extensor contractions) were assessed at the same time points, as well as ~20 h into recovery (day 1). Muscle glycogen decreased 31% (p < 0.001) postgame and had returned to pregame levels on day 2. MVIC dropped 11%, whereas 50 and 20 Hz torque dropped 21% and 29% postgame, respectively, inducing a 10% reduction in the 20/50 Hz torque ratio indicative of low-frequency force depression (all p < 0.001). While MVIC torque returned to baseline on day 1, 20 and 50 Hz torque remained depressed by 9%-11% (p = 0.010-0.040), hence restoring the pre-exercise 20/50 Hz ratio. Repeated-sprint ability was only marginally reduced by 1% postgame (p = 0.041) and fully recovered on day 1. In conclusion, an elite youth ice hockey game induces substantial reductions in muscle glycogen content and muscle function, but only minor reductions in repeated-sprint ability and with complete recovery of all parameters within 1-2 days postgame.

Dose-response effect of a recreational team handball-based exercise programme on cardiometabolic health and physical fitness in inactive middle-aged-to-elderly males - a randomised controlled trial

This study aimed at examining the dose-response of a recreational team handball (TH) exercise-based programme on cardiometabolic health and physical fitness in inactive middle-aged-to-elderly males without TH experience. Fifty-four inactive middle-aged-to-elderly men (67.5 ± 4.2 years; stature 168.8 ± 6.2 cm; body mass 78.4 ± 10.7 kg; fat mass 27.1 ± 5.3%; BMI 27.4 ± 2.9 kg/m2; VO2peak 27.3 ± 4.8 mL/min/kg) were randomised into three intervention groups performing 1 (TH1, n = 13), 2 (TH2, n = 15), or 3 (TH3, n = 12) 60-min weekly recreational TH-based training sessions, for 16 weeks, and a control group (CG, n = 14). A time x group interaction was observed for VO2peak, aerobic performance, fasting plasma insulin and body and fat mass (p ≤ 0.043) with TH3 showing the greatest overall effects. Post-intervention differences were observed in aerobic performance (TH3>CG, TH1 and TH2; TH2>CG), body mass (TH3>CG and TH1), fat mass (TH3>CG), VO2peak (TH3>CG) and plasma insulin (TH3>CG) (p ≤ 0.040). In conclusion, recreational TH performed for 60-min thrice and twice per week results in improved aerobic performance for middle-aged-to-elderly men. Moreover, it was observed that three weekly sessions were more effective in providing overall cardiometabolic benefits compared to training with a lower weekly frequency. ClinicalTrials.gov ID: NCT05295511.Trial registration: ClinicalTrials.gov identifier: NCT05295511.Highlights: We observed high intensities and fun levels during recreational TH, organised as formal and small-sided games, for middle-aged-to-elderly men during a 16-week period, independently of the number of weekly training sessions.Marked positive effects on aerobic performance and cardiometabolic health were observed in the intervention group that performed 3 weekly sessions.The study results indicate that recreational TH training with low frequency and volume results in some beneficial effects on cardiometabolic fitness and health for middle-aged-to-elderly men, but future studies with more participants or longer intervention periods are warranted to explore this possibility.

The angiotensin-converting enzyme I/D polymorphism does not impact training-induced adaptations in exercise capacity in patients with stable coronary artery disease

Systematic exercise training effectively improves exercise capacity in patients with coronary artery disease (CAD), but the magnitude of improvements is highly heterogeneous. We investigated whether this heterogeneity in exercise capacity gains is influenced by the insertion/deletion (I/D) polymorphism of the angiotensin-converting enzyme (ACE) gene. Patients with CAD (n = 169) were randomly assigned to 12 weeks of exercise training or standard care, and 142 patients completed the study. The ACE polymorphism was determined for 128 patients (82% males, 67 ± 9 years). Peak oxygen uptake was measured before and after the 12-week intervention. The ACE I/D polymorphism frequency was n = 48 for D/D homozygotes, n = 61 for I/D heterozygotes and n = 19 for I/I homozygotes. Baseline peak oxygen uptake was 23.3 ± 5.0 ml/kg/min in D/D homozygotes, 22.1 ± 5.3 ml/kg/min in I/D heterozygotes and 23.1 ± 6.0 ml/kg/min in I/I homozygotes, with no statistical differences between genotype groups (P = 0.50). The ACE I/D polymorphism frequency in the exercise group was n = 26 for D/D, n = 21 for I/D and n = 12 for I/I. After exercise training, peak oxygen uptake was increased (P < 0.001) in D/D homozygotes by 2.6 ± 1.7 ml/kg/min, in I/D heterozygotes by 2.7 ± 1.9 ml/kg/min, and in I/I homozygotes by 2.1 ± 1.3 ml/kg/min. However, the improvements were similar between genotype groups (time × genotype, P = 0.55). In conclusion, the ACE I/D polymorphism does not affect baseline exercise capacity or exercise capacity gains in response to 12 weeks of high-intensity exercise training in patients with stable CAD.Clinical trial registration: www.clinicaltrials.gov (NCT04268992).

Bone Health, Body Composition and Physiological Demands in 70-85-Year-Old Lifelong Male Football Players

The effects of lifelong football training on bone health, body composition and physiological demands were evaluated. A total of 20 veteran football players (VPG; 73.4 ± 3.7 years) and 18 untrained age-matched men (CG; 75.6 ± 4.2 years) were enrolled. Whole-body and regional dual-energy X-ray absorptiometry scans of arms, legs, proximal femur and lower spine (L1-L4) were recorded in all participants. We observerd higher bone mineral density (BMD) in the whole-body, arms and femoral regions and higher bone mineral content (BMC) in the legs and lower spine compared to the CG (p < 0.05), also higher total lean body mass (p < 0.05) and lower total body fat percentage (p < 0.05), were found. No differences in food habits were evidenced between the VPG and the CG, as evaluated using 3-day food records. Resting heart rate (RHR), blood pressure (BP) and activity profile during a football match were recorded using a global positioning system only in the VPG. The mean heart rate (HR)of theoretical maximal HR (ThHRmax), and peak of ThHRmax were 83.9 ± 8.6% and 98.6 ± 10.2%, respectively; the mean of total distance covered was 3666 ± 721 m, and the means of accelerations and decelerations were 419 ± 61 and 428 ± 65, respectively. Lifelong participation in football training improves regional BMD and BMC in legs, femur and lumbar spine compared to the CG. A high number of intense actions in term of HR and accelerations and decelerations suggests an elevated energy expenditure that in turn correlates to the healthier body composition observed in the VPG compared to the CG.

Recreational futsal provides broad-spectrum fitness and health benefits but no blood pressure effects in men with treated hypertension - a randomised controlled trial

We determined the coadjuvant effect of a recreational futsal (RF) programme versus standard care alone (CON) in men with treated arterial hypertension (TAHT). Thirty-nine men with TAHT were randomised to RF (N = 20; 48 ± 8 years; systolic blood pressure [SBP]: 122 ± 14 mmHg) with 2-3 one-hour sessions/week for 3 months, or to CON (N = 19; 51 ± 6 years; SBP: 126 ± 13 mmHg). Participants were assessed at baseline, at 3 months, and after 1 month of training cessation (4 months). Mean training attendance was 60 ± 23%. At 3-months, there were no between-group differences in BP parameters (SBP: 0.44 mmHg; 95% CI: -5.79, 6.67). However, compared to CON, RF was effective for peak oxygen uptake (2.76 mL.min-1.kg-1; 95% CI: 0.26, 5.26), time to exhaustion (1.15 min; 95% CI: 0.59, 1.69), Yo-Yo IE1 performance (365 m; 95% CI: 175, 556), resting heart rate (RHR; -5 b.min-1; 95% CI: -10, -1), glycated haemoglobin (-0.52 mmol/L; 95% CI: -0.84, -0.19), blood glucose (-0.25 mmol/L; 95% CI: -0.44, -0.06), left femur bone mineral content (1.96 g; 95% CI: 0.29, 3.65), and postural balance (-2.3 falls; 95% CI: -3.9, -0.6). Similar findings were observed after 1-month of training cessation, except for RHR and blood glucose that returned to baseline levels in the RF group. In conclusion, RF provides broad-spectrum fitness and health benefits but no BP effects in men with TAHT.

Whole-body kinematic adaptations to running on an unstable, irregular, and compliant surface

The goal of this study was to investigate whole-body kinematic adaptations when running on an unstable, irregular, and compliant surface in comparison to running on asphalt. We hypothesised that the gait pattern (H1) and its stride-to-stride variability (H2) would be affected by the unstable surface but that variability related to some movement features would be reduced over multiple testing days indicative of gait optimisation (H3). Fifteen runners ran on a woodchip and asphalt track on five testing days while their whole-body movements were captured using inertial motion capture and examined using joint angle and principal component analysis. Joint angles and stride-to-stride variability in eight principal running movements were subjected to surface by day analyses of variance. The woodchip track compared to asphalt resulted in (H1) a more crouched gait pattern including more leg flexion and forward trunk lean and (H2) higher stride-to-stride variability in most investigated principal running movements. However, (H3) stride-to-stride variability did not systematically change over testing days. Running on an unstable, irregular, and more compliant surface leads to the adoption a gait pattern and control strategy that are more robust against disturbances caused by the surface but may pose certain risks for overuse injury in trail runners.

Effects of the COVID-19-induced lockdown period on general well-being, perceived stress and activity levels in the Faroe Islands

AIMS

Detrimental effects on health and well-being were reported during the COVID-19-induced lockdown periods in several countries, but these associations have not been studied in small-scale island societies. This study aimed to examine the lockdown period's impact on general well-being, perceived stress and activity levels in the Faroe Islands.

METHODS

We used cross-sectional data from two extensive population-based surveys of the general health conducted in November 2019 (the pre-COVID survey; n=2906), and four to six weeks into the first national lockdown (the lockdown survey; n=1204).

RESULTS

A larger proportion of participants in the lockdown survey versus pre-COVID survey displayed excellent/very good self-rated health (68.1% vs. 62.0%; p<0.001), and the same pattern was observed for reporting good quality of life (85.7% vs. 82.7%; p<0.05). These associations remained statistically significant in a logistic regression model after adjusting for characteristics for which varying impact of the pandemic has been shown. Indicators of health behaviour showed that larger proportions of participants kept active during the lockdown survey versus pre-COVID survey, and these differences were statistically significant for physical, mental and spiritual activities (p<0.001). On the other hand, similar stress levels in the pre-COVID/lockdown periods were observed, but stratified analysis showed that participants with a high-stress level displayed better self-rated health in the lockdown period compared to the pre-COVID period (p=0.001).

CONCLUSIONS

Findings indicate that self-reported health and quality of life improved during the early phase of the COVID lockdown, and individuals reported higher activity levels associated with good mental health during the COVID-19-induced lockdown period.

Electromagnetic levitation containerless processing of metallic materials in microgravity: thermophysical properties

Transitions from the liquid to the solid state of matter are omnipresent. They form a crucial step in the industrial solidification of metallic alloy melts and are greatly influenced by the thermophysical properties of the melt. Knowledge of the thermophysical properties of liquid metallic alloys is necessary in order to gain a tight control over the solidification pathway, and over the obtained material structure of the solid. Measurements of thermophysical properties on ground are often difficult, or even impossible, since liquids are strongly influenced by earth's gravity. Another problem is the reactivity of melts with container materials, especially at high temperature. Finally, deep undercooling, necessary to understand nucleus formation and equilibrium as well as non-equilibrium solidification, can only be achieved in a containerless environment. Containerless experiments in microgravity allow precise benchmark measurements of thermophysical properties. The electromagnetic levitator ISS-EML on the International Space Station (ISS) offers perfect conditions for such experiments. This way, data for process simulations is obtained, and a deeper understanding of nucleation, crystal growth, microstructural evolution, and other details of the transformation from liquid to solid can be gained. Here, we address the scientific questions in detail, show highlights of recent achievements, and give an outlook on future work.

"11 for Health" in the Faroe Islands: Popularity in schoolchildren aged 10-12 and the effect on well-being and health knowledge

BACKGROUND

We aimed to investigate the popularity of the "11 for Health program for Europe" for 10-12-year-old Faroese children and the effects on well-being and health knowledge.

METHODS

We applied a cluster-randomized controlled trial, including a total of 19 school clusters, randomized into intervention schools (IG, n = 12) and control schools (CG, n = 7). A total of 261 children (137 boys and 124 girls) participated. IG completed the 11-week program, consisting of 2 × 45 min weekly sessions with football drills, small-sided games, and health education. CG continued their regular education. Pre- and post-intervention, the participants completed a shortened version of the multidimensional well-being questionnaire KIDSCREEN-27 and a 34-item multiple-choice health knowledge questionnaire.

RESULTS

Between-group differences (p < 0.05) were observed in change scores for physical well-being and overall peers and social support in favor of IG compared with CG, as well as for physical well-being in IG girls compared with CG girls. Between-group differences in change score for overall health knowledge (11.8%, p < 0.001, ES: 0.82) were observed in favor of IG, as well as for playing football (8.9%, p = 0.039, ES: 0.24), be active (8.1%, p = 0.017, ES: 0.32), control your weight (18.5%, p < 0.001, ES: 0.52), wash your hands (19.5%, p < 0.001, ES: 0.59), eat a balanced diet (19.3%, p < 0.001, ES: 0.64), get fit (12.1%, p = 0.007, ES: 0.34), and think positive (5.5%, p = 0.039, ES: 0.22). The program was reported as enjoyable with equal moderate-to-high scores for girls (3.68 ± 1.23; ±SD) and boys (3.84 ± 1.17) on a 1-5 Likert Scale.

CONCLUSION

The "11 for Health program for Europe" improved physical well-being, peers, and social support and broad-spectrum health knowledge in 10-12-year-old Faroese schoolchildren and was rated popular.

Football training as a non-pharmacological treatment of the global aging population-A topical review

In the present topical mini-review, the beneficial impact of small-sided game football training for the increasing elderly global population is presented. As a multicomponent type of physical activity, football training executed on small pitched with 4-6 players in each team is targeting a myriad of physiological systems and causes positive adaptations of relevance for several non-communicable diseases, of which the incidence increases with advancing age. There is strong scientific evidence that this type of football training promotes cardiovascular, metabolic and musculo-skeletal health in elderly individuals. These positive adaptations can prevent cardiovascular disease, type 2 diabetes, sarcopenia and osteoporosis, and lower the risk of falls. Also, football training has been proven an efficient part of the treatment of several patient groups including men with prostate cancer and women after breast cancer. Finally, regular football training has an anti-inflammatory effect and may slow the biological aging. Overall, there is a growing body of evidence suggesting that recreational football training can promote health in the elderly.

Robust arm and leg muscle adaptation to training despite ACE inhibition: a randomized placebo-controlled trial

PURPOSE

Angiotensin-converting enzyme (ACE) inhibitor treatment is widely applied, but the fact that plasma ACE activity is a potential determinant of training-induced local muscular adaptability is often neglected. Thus, we investigated the hypothesis that ACE inhibition modulates the response to systematic aerobic exercise training on leg and arm muscular adaptations.

METHODS

Healthy, untrained, middle-aged participants (40 ± 7 yrs) completed a randomized, double-blinded, placebo-controlled trial. Participants were randomized to placebo (PLA: CaCO₃) or ACE inhibitor (ACE_i: enalapril) for 8 weeks and completed a supervised, high-intensity exercise training program. Muscular characteristics in the leg and arm were extensively evaluated pre and post-intervention.

RESULTS

Forty-eight participants (n_ACEi = 23, n_PLA = 25) completed the trial. Exercise training compliance was above 99%. After training, citrate synthase, 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity were increased in m. vastus lateralis in both groups (all P < 0.05) without statistical differences between them (all time × treatment P > 0.05). In m. deltoideus, citrate synthase maximal activity was upregulated to a greater extent (time × treatment P < 0.05) in PLA (51 [33;69] %) than in ACE_i (28 [13;43] %), but the change in 3-hydroxyacyl-CoA dehydrogenase and phosphofructokinase maximal activity was similar between groups. Finally, the training-induced changes in the platelet endothelial cell adhesion molecule-1 protein abundance, a marker of capillary density, were similar in both groups in m. vastus lateralis and m. deltoideus.

CONCLUSION

Eight weeks of high-intensity whole-body exercise training improves markers of skeletal muscle mitochondrial oxidative capacity, glycolytic capacity and angiogenesis, with no overall effect of pharmacological ACE inhibition in healthy adults.

The Role of Muscle Glycogen Content and Localization in High-Intensity Exercise Performance: A Placebo-Controlled Trial

PURPOSE

We investigated the coupling between muscle glycogen content and localization and high-intensity exercise performance using a randomized, placebo-controlled, parallel-group design with emphasis on single-fiber subcellular glycogen concentrations and sarcoplasmic reticulum Ca 2+ kinetics.

METHODS

Eighteen well-trained participants performed high-intensity intermittent glycogen-depleting exercise, followed by randomization to a high- (CHO; ~1 g CHO·kg -1 ·h -1 ; n = 9) or low-carbohydrate placebo diet (PLA, <0.1 g CHO·kg -1 ·h -1 ; n = 9) for a 5-h recovery period. At baseline, after exercise, and after the carbohydrate manipulation assessments of repeated sprint ability (5 × 6-s maximal cycling sprints with 24 s of rest), neuromuscular function and ratings of perceived exertion during standardized high-intensity cycling (~90% Wmax ) were performed, while muscle and blood samples were collected.

RESULTS

The exercise and carbohydrate manipulations led to distinct muscle glycogen concentrations in CHO and PLA at the whole-muscle (291 ± 78 vs 175 ± 100 mmol·kg -1 dry weight (dw), P = 0.020) and subcellular level in each of three local regions ( P = 0.001-0.046). This was coupled with near-depleted glycogen concentrations in single fibers of both main fiber types in PLA, especially in the intramyofibrillar region (within the myofibrils). Furthermore, increased ratings of perceived exertion and impaired repeated sprint ability (~8% loss, P < 0.001) were present in PLA, with the latter correlating moderately to very strongly ( r = 0.47-0.71, P = 0.001-0.049) with whole-muscle glycogen and subcellular glycogen fractions. Finally, sarcoplasmic reticulum Ca 2+ uptake, but not release, was superior in CHO, whereas neuromuscular function, including prolonged low-frequency force depression, was unaffected by dietary manipulation.

CONCLUSIONS

Together, these results support an important role of muscle glycogen availability for high-intensity exercise performance, which may be mediated by reductions in single-fiber levels, particularly in distinct subcellular regions, despite only moderately lowered whole-muscle glycogen concentrations.

Fibre type- and localisation-specific muscle glycogen utilisation during repeated high-intensity intermittent exercise

Glycogen particles are situated in key areas of the muscle cell in the vicinity of the main energy-consumption sites and may be utilised heterogeneously dependent on the nature of the metabolic demands. The present study aimed to investigate the time course of fibre type-specific utilisation of muscle glycogen in three distinct subcellular fractions (intermyofibrillar, IMF; intramyofibrillar, Intra; and subsarcolemmal, SS) during repeated high-intensity intermittent exercise. Eighteen moderately to well-trained male participants performed three periods of 10 × 45 s cycling at ∼105% watt max (EX1-EX3) coupled with 5 × 6 s maximal sprints at baseline and after each period. Muscle biopsies were sampled at baseline and after EX1 and EX3. A higher glycogen breakdown rate in type 2 compared to type 1 fibres was found during EX1 for the Intra (-72 vs. -45%) and IMF (-59 vs. -35%) glycogen fractions (P < 0.001) but with no differences for SS glycogen (-52 vs. -40%). In contrast, no fibre type differences were observed during EX2-EX3, where the utilisation of Intra and IMF glycogen in type 2 fibres was reduced, resulting in depletion of all three subcellular fractions to very low levels post-exercise within both fibre types. Importantly, large heterogeneity in single-fibre glycogen utilisation was present with an early depletion of especially Intra glycogen in individual type 2 fibres. In conclusion, there is a clear fibre type- and localisation-specific glycogen utilisation during high-intensity intermittent exercise, which varies with time course of exercise and is characterised by exacerbated pool-specific glycogen depletion at the single-fibre level. KEY POINTS: Muscle glycogen is the major fuel during high-intensity exercise and is stored in distinct subcellular areas of the muscle cell in close vicinity to the main energy consumption sites. In the present study quantitative electron microscopy imaging was used to investigate the utilisation pattern of three distinct subcellular muscle glycogen fractions during repeated high-intensity intermittent exercise. It is shown that the utilisation differs dependent on fibre type, subcellular localisation and time course of exercise and with large single-fibre heterogeneity. These findings expand on our understanding of subcellular muscle glycogen metabolism during exercise and may help us explain how reductions in muscle glycogen can attenuate muscle function even at only moderately lowered whole-muscle glycogen concentrations.

Haemostasis and fibrinolysis after regular high-intensity interval training in patients with coronary artery disease: a randomised controlled trial

Patients with coronary artery disease (CAD) have prothrombotic changes compared with healthy individuals. Regular exercise reduces cardiovascular mortality in patients with stable CAD. However, the underlying mechanism for the beneficial effect is unknown. We investigated whether regular exercise would inhibit platelet aggregation and thrombin generation and increase fibrinolysis in patients with CAD.

Materials and methods

Patients with CAD were randomised 1:1 to a supervised high-intensity exercise training programme or standard care for 12 weeks. Blood samples were obtained at baseline and after 6 and 12 weeks. Platelet aggregation was evaluated with the Multiplate Analyser, thrombin generation using the calibrated automated thrombogram and fibrinolysis employing a clot lysis assay.

Results

A total of 169 stable patients with CAD were randomised, and 142 patients (67±9 years, 83% males) completed the study; 64 in the exercise group and 78 in the standard care group. All but one patients received single antiplatelet therapy. From baseline to 12 weeks postintervention (Δ), no significant between-group differences were found in adenosine diphosphate-induced platelet aggregation (Δ−15 aggregation units (AU), AU×min, 95% CI −70 to 40 in the exercise group and Δ−26 AU×min, 95% CI −77 to 26 in the standard care group, p=0.44); endogenous thrombin potential (medians: Δ−5%, 95% CI −12 to 3 in the exercise group and Δ−6%, 95% CI −13 to 1 in the standard care group, p=0.26); nor in 50% clot lysis time (medians: Δ−9%, 95% CI −23 to 7 in the exercise group and Δ−17%, 95% CI −29 to −3 in the standard care group, p=0.60).

Conclusions

Twelve weeks of high-intensity whole-body endurance exercise did not affect platelet aggregation, thrombin generation or fibrinolysis in patients with stable CAD.

Trial registration number

NCT04268992.

Feasibility and impact of whole-body high-intensity interval training in patients with stable coronary artery disease: a randomised controlled trial

Exercise training reduces cardiovascular mortality and improves quality of life in CAD patients. We investigated the feasibility and impact of 12 weeks of low-volume high-intensity interval training (HIIT) in CAD-patients. Patients with stable CAD were randomized 1:1 to supervised HIIT or standard care. HIIT sessions were completed three times weekly for 12 weeks on a rowing ergometer. Before and after the 12-week intervention, patients completed a physiological evaluation of cardiorespiratory performance and quality of life questionnaires. Mixed model analysis was used to evaluate differences between and within groups. A total of 142 patients (67 ± 9 years, n_HIIT = 64, n_{Standard care} = 78) completed the trial. Training adherence was 97% (range 86-100%). Six patients dropped out because of non-fatal adverse events. Weekly training duration was 54 min with an average power output of 138 W. HIIT increased peak oxygen uptake by 2.5 mL/kg/min (95% CI 2.1-3.0), whereas no change was observed in standard care (0.2 mL/kg/min, 95% CI - 0.2-0.6, P < 0.001). In addition, HIIT improved markers of quality of life, including physical functioning, limitations due to physical illness, general health and vitality (P < 0.05). Twelve weeks of low-volume whole-body HIIT increased cardiorespiratory capacity and improved quality of life in patients with stable CAD compared to standard care. In addition, our study demonstrates that the applied vigorous training regime is feasible for this patient group.Clinical trial registration: www.clinicaltrials.gov . Identification number: NCT04268992.

Effect of supervised high-intensity interval training on haemostasis in patients with coronary artery disease: a randomised controlled trial

Background

Regular exercise training is recommended for patients with stable coronary artery disease (CAD), because it improves quality of life and reduces cardiovascular mortality and hospital admissions. CAD patients benefit from anti-thrombotic therapy and may have a pro-coagulant condition compared to healthy individuals. Long-term exercise training may reduce platelet aggregation and coagulation and increase fibrinolysis.

Purpose

We aimed to investigate if supervised high-intensity interval training affects haemostasis in patients with stable CAD.

Methods

We randomised stable CAD patients to supervised high-intensity interval training or standard care. High-intensity exercise training was performed on rowing ergometers three times weekly for 12 weeks. Blood samples were obtained in all patients prior to randomisation (baseline) and after 6 and 12 weeks. We evaluated platelet aggregation with the Multiplate® Analyzer, thrombin generation using the Calibrated Automated Thrombogram and fibrinolysis employing an in-house clot lysis assay. Between group differences were evaluated with mixed model analysis using SPSS. According to our sample size calculation, we have a statistical power of 88% to detect a difference of 25% in clot lysis time.

Results

A total of 142 patients with stable CAD (mean age 67±9 years, 83% males) completed the study; 64 in the exercise group and 78 in the control group. The weekly average active training duration was 54 min, and adherence to training was 97%. When comparing the two groups (exercise vs. standard care) from baseline to post intervention, we found no significant changes in ADP-induced platelet aggregation (difference between baseline and 12 weeks (Δ) 11 AU·min, 95% confidence interval (CI): −46–68 in the exercise group and Δ24 AU·min, 95% CI: −28–77 in the standard care group, p=0.52), thrombin generation (endogenous thrombin potential Δ45 nM·min, 95% CI: −77–166 in the exercise group and Δ103 nM·min, 95% CI: −7–212 in the standard care group, p=0.18) or fibrinolysis (50% clot lysis time Δ62 sec, 95% CI: −136–261 in the exercise group and Δ215 sec, 95% CI: 38–391 in the standard care group, p=0.39).

Conclusion

High-intensity interval training did not have major effects on platelet aggregation, thrombin generation nor fibrinolysis in patients with stable CAD.

Funding Acknowledgement

Type of funding sources: Public Institution(s). Main funding source(s): Aarhus UniversityThe Faroese Health Research Foundation (Sjúkrakassagrunnurin)

CRISPR-Cas12a nucleases function with structurally engineered crRNAs: SynThetic trAcrRNA

CRISPR-Cas12a systems are becoming an attractive genome editing tool for cell engineering due to their broader editing capabilities compared to CRISPR-Cas9 counterparts. As opposed to Cas9, the Cas12a endonucleases are characterized by a lack of trans-activating crRNA (tracrRNA), which reduces the complexity of the editing system and simultaneously makes CRISPR RNA (crRNA) engineering a promising approach toward further improving and modulating editing activity of the CRISPR-Cas12a systems. Here, we design and validate sixteen types of structurally engineered Cas12a crRNAs targeting various immunologically relevant loci in-vitro and in-cellulo. We show that all our structural modifications in the loop region, ranging from engineered breaks (STAR-crRNAs) to large gaps (Gap-crRNAs), as well as nucleotide substitutions, enable gene-cutting in the presence of various Cas12a nucleases. Moreover, we observe similar insertion rates of short HDR templates using the engineered crRNAs compared to the wild-type crRNAs, further demonstrating that the introduced modifications in the loop region led to comparable genome editing efficiencies. In conclusion, we show that Cas12a nucleases can broadly utilize structurally engineered crRNAs with breaks or gaps in the otherwise highly-conserved loop region, which could further facilitate a wide range of genome editing applications.

Effect of angiotensin-converting enzyme inhibition on cardiovascular adaptation to exercise training

Angiotensin-converting enzyme (ACE) activity may be one determinant of adaptability to exercise training, but well-controlled studies in humans without confounding conditions are lacking. Thus, the purpose of the present study was to investigate whether ACE inhibition affects cardiovascular adaptations to exercise training in healthy humans. Healthy participants of both genders (40 ± 7 years) completed a randomized, double-blind, placebo-controlled trial. Eight weeks of exercise training combined with placebo (PLA, n = 25) or ACE inhibitor (ACEi, n = 23) treatment was carried out. Before and after the intervention, cardiovascular characteristics were investigated. Mean arterial blood pressure was reduced (p < 0.001) by -5.5 [-8.4; -2.6] mmHg in ACEi , whereas the 0.7 [-2.0; 3.5] mmHg fluctuation in PLA was non-significant. Maximal oxygen uptake increased (p < 0.001) irrespective of ACE inhibitor treatment by 13 [8; 17] % in ACEi and 13 [9; 17] % in PLA. In addition, skeletal muscle endurance increased (p < 0.001) to a similar extent in both groups, with magnitudes of 82 [55; 113] % in ACEi and 74 [48; 105] % in PLA. In contrast, left atrial volume decreased (p < 0.05) by -9 [-16; -2] % in ACEi , but increased (p < 0.01) by 14 [5; 23] % in PLA. Total hemoglobin mass was reduced (p < 0.01) by -3 [-6; -1] % in ACEi , while a non-significant numeric increase of 2 [-0.4; 4] % existed in PLA. The lean mass remained constant in ACEi but increased (p < 0.001) by 3 [2; 4] % in PLA. In healthy middle-aged adults, 8 weeks of high-intensity exercise training increases maximal oxygen uptake and skeletal muscle endurance irrespective of ACE inhibitor treatment. However, ACE inhibitor treatment counteracts exercise training-induced increases in lean mass and left atrial volume. ACE inhibitor treatment compromises total hemoglobin mass.

Effects of Postdischarge High-Protein Oral Nutritional Supplements and Resistance Training in Malnourished Surgical Patients: A Pilot Randomized Controlled Trial

The presence of malnutrition is increasingly becoming a postdischarge problem in surgical patients. We aimed to investigate whether oral nutritional supplements combined with resistance training could minimize skeletal muscle atrophy in surgical patients after discharge. This randomized controlled study was conducted at the Department of Surgery, National Hospital of Faroe Islands from 2018 to 2020. A total of 45 patients aged 37−74 years participated and were allocated to one of three groups: diet (DI; n = 13), exercise and diet (EX + DI; n = 16), or control (CON; n = 16). The intervention period lasted 8 weeks. The intervention groups received individual dietary counselling and a protein-rich oral nutritional supplement twice a day containing 22 g of protein/day. Patients in the EX + DI group were assigned to resistance training sessions. Patients in the CON group received standard care. The primary outcome was change in lean body mass (LBM). Secondary outcomes were change in body weight, handgrip strength, quality of life, surgery-related side effects, energy and protein intake, length of stay and one-year mortality. To estimate within-group changes, linear mixed models including group−time interactions as fixed effects and patients as random effects were fitted. Within-group change in LBM was 233, 813 and 78 g in the DI, EX + DI and CON groups, respectively, with no significant between-group difference (p > 0.05). Pain score declined more (p = 0.04) in the EX + DI group compared with the CON group. Body weight, handgrip strength, quality of life and surgery-related side effects did not differ between groups. At the end of study, mean cumulative weight change in the DI and EX + DI groups was 0.4% and 1.6%, respectively, whereas the CON group experienced a weight loss of −0.6%. No significant difference in primary outcome between groups was noted. However, our results indicate some benefits from exercise and nutrition for malnourished surgical patients.

Comparative Efficacy of 5 Exercise Types on Cardiometabolic Health in Overweight and Obese Adults: A Systematic Review and Network Meta-Analysis of 81 Randomized Controlled Trials

BACKGROUND

Although regular exercise is recommended for preventing and treating overweight/obesity, the most effective exercise type for improving cardiometabolic health in individuals with overweight/obesity remains largely undecided. This network meta-analysis aimed to evaluate and rank the comparative efficacy of 5 exercise modalities on cardiometabolic health measures in individuals with overweight/obesity.

METHODS

A database search was conducted in MEDLINE, Embase, Scopus, and Web of Science from inception up to September 2020. The review focused on randomized controlled trials involving exercise interventions consisting of continuous endurance training, interval training, resistance training, combined aerobic and resistance training (combined training), and hybrid-type training. Exercise interventions aimed to improve somatometric variables, body composition, lipid metabolism, glucose control, blood pressure, cardiorespiratory fitness, and muscular strength. The Cochrane risk of bias tool was used to evaluate eligible studies. A random-effects network meta-analysis was performed within a frequentist framework. The intervention ranking was carried out using a Bayesian model where mean and SD were equal to the respective frequentist estimates.

RESULTS

A total of 4331 participants (59% female; mean age: 38.7±12.3 years) from 81 studies were included. Combined training was the most effective modality and hybrid-type training the second most effective in improving cardiometabolic health-related outcomes in these populations suggesting a higher efficacy for multicomponent exercise interventions compared to single-component modalities, that is, continuous endurance training, interval training, and resistance training. A subgroup analysis revealed that the effects from different exercise types were mediated by gender.

CONCLUSIONS

These findings corroborate the latest guidelines on exercise for individuals with overweight/obesity highlighting the importance of a multicomponent exercise approach to improve cardiometabolic health. Physicians and healthcare professionals should consider prescribing multicomponent exercise interventions to adults with overweight/obesity to maximize clinical outcomes.

REGISTRATION

URL: https://www.crd.york.ac.uk/PROSPERO/; Unique identifier: CRD42020202647.

Acute arm and leg muscle glycogen and metabolite responses to small-sided football games in healthy young men

PURPOSE

Studies have indicated upper body involvement during football, provoking long-term muscular adaptations. This study aimed at examining the acute metabolic response in upper and lower body skeletal muscle to football training organized as small-sided games (SSG).

METHODS

Ten healthy male recreational football players [age 24 ± 1 (± SD) yrs; height 183 ± 4 cm; body mass 83.1 ± 9.7 kg; body fat 15.5 ± 5.4%] completed 1-h 5v5 SSG (4 × 12 min interspersed with 4-min recovery periods). Muscle biopsies were obtained from m. vastus lateralis (VL) and m. deltoideus (DE) pre- and post-SSG for muscle glycogen and metabolite analyses. Blood lactate samples were obtained at rest, middle and end of the SSG.

RESULTS

Muscle glycogen in VL decreased (P < 0.01) by 21% and tended (P = 0.08) to decrease in DE by 13%. Muscle lactate increased in VL (117%; P < 0.001) and DE (81%; P < 0.001) during the game, while blood lactate rose threefold. Muscle ATP and PCr were unaltered, but intermuscular differences were detected for ATP at both time points (P < 0.001) and for PCr at pre-SSG (P < 0.05) with VL demonstrating higher values than DE, while muscle creatine rose in VL (P < 0.001) by 41% and by 22% in DE (P = 0.02). Baseline citrate synthase maximal activity was higher (P < 0.05) in VL compared to DE, whereas baseline muscle lactate concentration was higher (P < 0.05) in DE than VL.

CONCLUSION

The upper body may be extensively involved during football play, but besides a rise in muscle lactate in the deltoideus muscle similar to the leg muscles, the present study did not demonstrate acute metabolic changes of an order that may explain the previously reported training effect of football play in the upper extremities.

Muscle Glycogen in Elite Soccer – A Perspective on the Implication for Performance, Fatigue, and Recovery

Based on extrapolation of current trends in modern soccer, physiological loading has increased markedly, and the game will continue to become even more demanding in the future, which will exacerbate fatigue at the end of a game and between games. Soccer is a glycogen consuming activity due to its high-intensity intermittent nature, and muscle glycogen is a key factor associated with fatigue late in a game, as well as in determining recovery after a game or an intense training session. Low glycogen in individual muscle fibers and subcellular compartments in the muscle cell is likely to negatively affect several essential steps in the excitation-contraction coupling such as action potential propagation, calcium handling and cross-bridge cycling through reductions in muscle ATP which are suggested sites of muscle function impairment inducing muscle fatigue. Recovery of physical performance and muscle glycogen after a soccer game is a slow process, which challenges the reality in modern elite soccer with increased game and training frequency and physiological loading. We suggest a markedly higher prioritization of fitness training modalities, nutritional approaches and general recovery strategies that optimizes muscle glycogen storage prior to games and training sessions. Also, the soccer community including the governing bodies of the sport must acknowledge and plan according to the high and increasing demands of the modern game, as well as the consequences this has on fatigue and recovery. These aspects are paramount to consider in the planning of training and games, as well as in the process of structuring soccer tournaments and developing competitive regulations in the future to optimize performance and player health.

Executive summary: Elite women's football-Performance, recovery, diet, and health

The present special issue of Scandinavian Journal of Medicine & Science in Sports focuses on performance, recovery, diet, and health in elite women’s football. Beside this summary, an editorial, topic reviews, and original articles written by several of the most published authors in football research are presented. It is, for example, highlighted that there is a great gender inequality in football research in favor of men, especially within elite football populations. Therefore, the broad‐spectrum content of the special issue with focus on several performance areas in women’s football, recovery strategies, nutrition, and psychological factors is highly warranted. Several of the topics examined and data presented are examined for the first on elite women’s football, and therefore, we hope that this special issue will contribute to gender balance the research and emphasis on football in both genders.

Improving hydration in elite male footballers during a national team training camp – an observational case study

[Purpose] The purpose of this study was to (i) assess hydration levels in elite male football players during a national team training camp before and during qualifying matches, (ii) evaluate the effect of coaching strategies for hydration based on feedback from hydration monitoring, and (iii) assess possible relationships between hydration status and training load or wellness markers.[Methods] Thirty-one male players (age 27±4 yrs; height 185±6 cm; weight 82.9±6.7 kg; body fat 10.4±2.3%) representing a national team from the Union of European Football Associations (UEFA) participated. The players were studied during three different national team training camps related to the UEFA Nations League tournament. Urine specific gravity (USG) was measured to assess hydration status. During all camps, the players were actively coached on improving strategies for hydration and given individual feedback on their test results. The training load was measured using GPS technology, and wellness questionnaires were completed.[Results] USG decreased progressively and significantly (p<0.005) during camp 1 and hydration status improved over the three camps, with fewer dehydrated and more well-hydrated players identified during the last part of camp 3. Significantly (p<0.05) higher USG values were observed 2 days prior to a match (MD-2) than on match day (MD); consequently, 52% of the players were dehydrated on MD-2 and only 6% on MD. No correlations were observed between hydration status and training load or wellness markers.[Conclusion] Dehydration is a challenge in elite male football, but continuous monitoring of hydration status and coaching on hydration strategies can lead to major improvements and reduce the degree of dehydration.

Nutritional optimization for female elite football players-topical review

Women's football is an intermittent sport characterized by frequent intense actions throughout the match. The high number of matches with limited recovery time played across a long competitive season underlines the importance of nutritional strategies to meet these large physical demands. In order to maximize sport performance and maintain good health, energy intake must be optimal. However, a considerable proportion of female elite football players does not have sufficient energy intake to match the energy expenditure, resulting in low energy availability that might have detrimental physiologic consequences and impair performance. Carbohydrates appear to be the primary fuel covering the total energy supply during match-play, and female elite football players should aim to consume sufficient carbohydrates to meet the requirements of their training program and to optimize the replenishment of muscle glycogen stores between training bouts and matches. However, several macro- and micronutrients are important for ensuring sufficient energy and nutrients for performance optimization and for overall health status in female elite football players. The inadequacy of macro-and micronutrients in the diet of these athletes may impair performance and training adaptations, and increase the risk of health disorders, compromising the player's professional career. In this topical review, we present knowledge and relevant nutritional recommendations for elite female football players for the benefit of sports nutritionists, dietitians, sports scientists, healthcare specialists, and applied researchers. We focus on dietary intake and cover the most pertinent topics in sports nutrition for the relevant physical demands in female elite football players as follows: energy intake, macronutrient and micronutrient requirements and optimal composition of the everyday diet, nutritional and hydration strategies to optimize performance and recovery, potential ergogenic effects of authorized relevant supplements, and future research considerations.

Skeletal muscle phenotype and game performance in elite women football players

We combined game activity analyses with skeletal muscle phenotypes and comprehensive physiological testing to elucidate factors of importance for physical performance in elite women's football. GPS-data from an experimental game, sprint and endurance testing, and muscle tissue analysis of metabolic enzyme activity, protein expression and fiber type composition were completed for international top-level women players (n = 20; age; 23 ± 4 yrs, height; 166 ± 10 cm, weight; 60 ± 8 kg; VO_2max ; 51 ± 6 ml/min/kg). Muscle monocarboxylate transporter 4 (MCT4) protein expression explained 46% of the variance in total game distance, while the ability to maintain high-intensity running (HIR) during the final 15 min of the game correlated to myosin heavy chain 1 (MHCI) and Na⁺ -K⁺ ATPase β1, FXYD1 (phospholemman) and superoxide dismutase 2 (SOD2) protein expression (range: r = 0.51-0.71; all p < 0.05). Total HIR distance correlated with (MHCIIa) protein expression (r = 0.51; p < 0.05), while muscle Na⁺ /H⁺ exchanger 1 (NHE1) protein explained 36% of the variance in game sprint distance (p < 0.05). Total game accelerations (actions >4 m/s² ) correlated with platelet endothelial cell adhesion molecule (PECAM-1) protein expression (r = 0.51; p < 0.05), while concentric knee flexor strength explained 42-62% of the variance in intense decelerations (>4 m/s² ). In conclusion, for elite women players' game endurance performance and resistance to end-game fatigue were affected by monocarboxylate transporter expression and myosin heavy chain profile. HIR was also correlated to ion transporter expression and muscle antioxidative capacity. Finally, the importance of functional strength and measures of muscle vascularization in relation to total game decelerations and accelerations, respectively, illustrates the complex physiological demands in elite women's football.

Physical workload and fatigue pattern characterization in a top-class women's football national team: a case study of the 2019 FIFA Women's World Cup

BACKGROUND

With the growing scientific interest in women's football it is critical to understand the match demands and fatigue patterns during a top-class women's competition.

METHODS

Physical characteristics and performance of top-class women football matches during the 2019 FIFA Women's World Cup was investigated from data collected using global positioning system for 21 outfield players during the tournament.

RESULTS

Relative total distance (TD; m·min^-1) was moderately lower (P≤0.05, ES:0.6) in the final match (96.1±5.0 m·min^-1) compared to the first (104.1±5.9 m·min^-1) match. Performance in relative total high-speed running (THSR; m·min^-1) declined -27.5% (P≥0.05) throughout the tournament following peak performance in the third match (M3) (5.3±1.7 m·min^-1). Match performance between halves was reduced -25.4±0.13% (P≤0.05, ES:1.2-2.3) across all measures in M3. Relative high-intensity running (HIR; 25.9±3.5 m·min^-1) and THSR (9.8±1.5 m·min^-1) were greater (P≤0.05, ES:0.2-0.7) for forwards, while midfielders performed greater (P≤0.05, ES:0.6) relative total distance (102.0±5.5 m·min^-1), compared to central defenders (HIR: 16.1±3.7 m·min^-1; THSR: 3.1±1.6 m·min^-1; TD: 92.5±5.7 m·min^-1). Reductions in relative HIR between halves (-10.9%), within the first half (-31.0%), and the start and end of the match (-36.9%) were most pronounced for midfielders (P≤0.05, ES:0.6-2.3). Across all matches, relative THSR performance was reduced, with moderate to large differences (P≤0.001, ES: 0.7-0.8) observed between halves, within the first half, and throughout the match.

CONCLUSIONS

In conclusion, specific fatigue patterns observed within and between matches throughout the women's World Cup, may be influenced by playing positions, the rank of the opposition, as well as the stage of the tournament.

Muscle metabolism and impaired sprint performance in an elite women's football game

The present study examined skeletal muscle metabolism and changes in repeated sprint performance during match play for n = 20 competitive elite women outfield players. We obtained musculus vastus lateralis biopsies and blood samples before, after, and following intense periods in each half of a friendly match, along with 5 × 30-meter sprint tests and movement pattern analyses (10-Hz S5 Global Positioning System [GPS]). Muscle glycogen decreased by 39% and 42% after an intense period of the second half and after the match, respectively, compared to baseline (p < 0.05). Post-match, 80% type I fibers and 69% type II fibers were almost empty or completely empty of glycogen. Muscle lactate was higher (p < 0.05) after the intense period of the first half and post-match compared to baseline (14.3 ± 4.6 (±SEM) and 12.9 ± 5.7 vs. 6.4 ± 3.7 mmol/kg d.w.). Muscle phosphocreatine was reduced (p < 0.05) by 16% and 12%, respectively, after an intense period in the first and second half compared to baseline. Blood lactate and glucose increased during the match and peaked at 8.4 ± 2.0 and 7.9 ± 1.2 mmol/L, respectively. Mean 5 × 30 m sprint time declined by 3.2 ± 1.7 and 7.0 ± 2.1% after the first and second half, respectively, and 4.7 ± 1.6% (p < 0.05) after an intense period in the first half compared to baseline. In conclusion, match play in elite female football players resulted in marked glycogen depletion in both fiber types, which may explain fatigue at the end of a match. Repeated sprint ability was impaired after intense periods in the first half and after both halves, which may be associated with the observed muscle metabolite perturbations.

Social inequality in type 2 diabetes mellitus in the Faroe Islands: a cross-sectional study

Aims: The Faroe Islands is considered a homogeneous society and has a low Gini coefficient, but the knowledge about the social distribution of health and disease is sparse. In a large population-based sample we investigated: (a) the association between socioeconomic position defined by level of education and the prevalence of type 2 diabetes mellitus by self-report in the Faroe Islands; and (b) to what degree lifestyle factors mediate the association. Methods: We used cross-sectional data from the population-based Public Health Survey Faroes 2015 (n=1095). We present odds ratios for type 2 diabetes mellitus by socioeconomic position from logistic regression models. In our main model we adjusted for potential confounders and in a secondary model we additionally adjusted for potential mediating lifestyle factors. Results: Individuals with middle and low levels of education display higher odds ratios of type 2 diabetes mellitus of 2.80 (95% confidence interval 1.32-5.92) and 4.65 (95% confidence interval 1.93-11.17) in adjusted analysis, respectively, compared to their counterparts with high education. After adjustment for potentially mediating lifestyle factors the estimates were attenuated slightly, but a significant statistical association remained, with lifestyle-related mediating factors in total explaining 21% for middle education and 34% for low education participants. Conclusions: Our results demonstrate that there may be a social gradient in the distribution of type 2 diabetes mellitus in the Faroe Islands, and that the association is partly mediated by lifestyle factors.

On-Ice and Off-Ice Fitness Profiles of Elite and U20 Male Ice Hockey Players of Two Different National Standards

Vigh-Larsen, JF, Haverinen, MT, Panduro, J, Ermidis, G, Andersen, TB, Overgaard, K, Krustrup, P, Parkkari, J, Avela, J, Kyröläinen, H, and Mohr, M. On-ice and off-ice fitness profiles of elite and U20 male ice hockey players of two different national standards. J Strength Cond Res 34(12): 3369-3376, 2020-Differences in body composition and performance were investigated between elite and U20 male ice hockey players of 2 different national standards. One hundred seventy-nine players were recruited from the highest Finnish (n = 82) and Danish (n = 61) national level, as well as from 1 U20 team from Finland (n = 19) and Denmark (n = 17). Body composition and countermovement jump performance (CMJ) were measured off-ice in addition to on-ice assessments of agility, 10- and 30-m sprint performance, and endurance capacity (the maximal Yo-Yo Intermittent Recovery Level 1 Ice Hockey Test, Yo-Yo IR1-IHmax). Large differences in on-ice performances were demonstrated between Finnish and Danish elite players for agility, 10- and 30-m sprint performance (2-3%, P ≤ 0.05), and Yo-Yo IR1-IHmax performance (15%, P ≤ 0.05). By contrast, no differences (P > 0.05) were present between elite players for CMJ ability or body composition. However, elite players possessed more body and muscle mass than U20 players. Finally, the Finnish U20 cohort had a similar performance level as the Danish elite players and superior 10-m sprint performance, whereas the Danish U20 level was inferior to the other groups in every performance assessment (P ≤ 0.05). In conclusion, on-ice speed and endurance differ markedly between elite players of 2 different national standards with no distinction in body composition or CMJ ability. Moreover, the most consistent difference between U20 and senior elite players was related to body and muscle mass. These results highlight the usefulness of on-ice assessments and suggest the importance of on-ice high-intensity training in elite players in addition to training targeted the development of lean body mass in youth prospects.

Effect of whey vs. soy protein supplementation on recovery kinetics following speed endurance training in competitive male soccer players: a randomized controlled trial

Background

Soccer-specific speed-endurance training induces short-term neuromuscular fatigue and performance deterioration over a 72-h recovery period, associated with elevated markers of exercise-induced muscle damage. We compared the effects of whey vs. soy protein supplementation on field activity, performance, muscle damage and redox responses following speed-endurance training in soccer players.

Methods

Ten well-trained, male soccer players completed three speed-endurance training trials, receiving whey protein (WP), soy protein (SP) or an isoenergetic placebo (PL; maltodextrin) according to a randomized, double-blind, crossover, repeated-measures design. A pre-loading period was applied in each trial during which protein supplementation was individually adjusted to reach a total protein intake of 1.5 g/kg/day, whereas in PL protein intake was adjusted at 0.8–1 g/kg/day. Following pre-loading, two speed-endurance training sessions (1 and 2) were performed 1 day apart, over a 3-day experimental period. During each session, field activity and heart rate were continuously monitored using global positioning system and heart rate monitors, respectively. Performance (isokinetic strength of knee extensors and flexors, maximal voluntary isometric contraction, speed, repeated sprint ability, countermovement jump), muscle damage (delayed-onset of muscle soreness, creatine kinase activity) and redox status (glutathione, total antioxidant capacity, protein carbonyls) were evaluated at baseline (pre), following pre-loading (post-load), and during recovery from speed-endurance training.

Results

High-intensity and high-speed running decreased (P ≤ 0.05) during speed-endurance training in all trials, but WP and SP mitigated this response. Isokinetic strength, maximal voluntary isometric contraction, 30-m speed, repeated sprint ability and countermovement jump performance were similarly deteriorated during recovery following speed-endurance training in all trials (P ≤ 0.05). 10 m speed was impaired at 24 h only in PL. Delayed-onset of muscle soreness, creatine kinase, total antioxidant capacity and protein carbonyls increased and glutathione decreased equally among trials following speed-endurance training (P ≤ 0.05), with SP inducing a faster recovery of protein carbonyls only at 48 h (P ≤ 0.05) compared to WP and PL.

Conclusions

In conclusion, increasing daily protein intake to 1.5 g/kg through ingestion of either whey or soy protein supplements mitigates field performance deterioration during successive speed-endurance training sessions without affecting exercise-induced muscle damage and redox status markers.

Trial registration

Name of the registry: clinicaltrials.gov. Trial registration: NCT03753321. Date of registration: 12/10/2018.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12970-021-00420-w.

Muscle Metabolism and Fatigue during Simulated Ice Hockey Match-Play in Elite Players

PURPOSE

The present study investigated muscle metabolism and fatigue during simulated elite male ice hockey match-play.

METHODS

Thirty U20 male national team players completed an experimental game comprising three periods of 8 × 1-min shifts separated by 2-min recovery intervals. Two vastus lateralis biopsies were obtained either during the game (n = 7) or pregame and postgame (n = 6). Venous blood samples were drawn pregame and at the end of the first and last periods (n = 14). Activity pattern and physiological responses were continuously monitored using local positioning system and heart rate recordings. Further, repeated-sprint ability was tested pregame and after each period.

RESULTS

Total distance covered was 5980 ± 199 m with almost half the distance covered at high skating speeds (>17 km·h). Average and peak on-ice heart rate was 84% ± 2% and 97% ± 2% of maximum heart rate, respectively. Muscle lactate increased (P ≤ 0.05) more than fivefold and threefold, whereas muscle pH decreased (P ≤ 0.05) from 7.31 ± 0.04 pregame to 6.99 ± 0.07 and 7.13 ± 0.11 during the first and last periods, respectively. Muscle glycogen decreased by 53% postgame (P ≤ 0.05) with ~65% of fast- and slow-twitch fibers depleted of glycogen. Blood lactate increased sixfold (P ≤ 0.05), whereas plasma free fatty acid levels increased 1.5-fold and threefold (P ≤ 0.05) after the first and last periods. Repeated-sprint ability was impaired (~3%; P ≤ 0.05) postgame concomitant with a ~10% decrease in the number of accelerations and decelerations during the second and last periods (P ≤ 0.05).

CONCLUSIONS

Our findings demonstrate that a simulated ice hockey match-play scenario encompasses a high on-ice heart rate response and glycolytic loading resulting in a marked degradation of muscle glycogen, particularly in specific sub-groups of fibers. This may be of importance both for fatigue in the final stages of a game and for subsequent recovery.

Danger zone assessment in small-sided recreational football: providing data for consideration in relation to COVID-19 transmission

During the COVID-19 pandemic, physical inactivity has increased, and a wide range of sporting activities locked down, with possible long-term implications for public health. Football is the most popular sport worldwide, and recreational football training leads to broad-spectrum health effects. Football is, however, deemed a contact sport with frequent close contact important to consider during COVID-19 pandemic.

OBJECTIVES

This study investigated time spent with close contact (danger zone (DZ) within 1.5 m), number of contacts and time per contact, and compared game formats in recreational small-sided football games for young and adult male football players.

METHODS

Movement analyses were performed on 10 Hz Global Positioning System (GPS) data collected during various small-sided football games prior to the COVID-19 outbreak.

RESULTS

Time spent in the DZ was 4.3-7.9 s/h per per cent infected players, corresponding to 34.3-114.8 s/h if one player was infected. Number of contacts with one infected player was 23.5-87.7 per hour, with an average contact time of 1.1-1.4 s, and a total number of contacts of 311-691 per hour with all players. 53%-65% of all contacts were shorter than 1 s and 77%-85% shorter than 2 s. Trivial to small effects were found for number of participants and area per player, whereas standard of play and playing with/without boards had no effect.

CONCLUSION

This study demonstrated that during small-sided football limited time is spent within DZ and that player contacts are brief. Recreational football may therefore more appropriately be deemed as sporting activity with brief, sporadic contact.