Investigating effects of FFP2 wearing during physical activity on gas exchange, metabolism and affective state using a randomized controlled trial.

Concerns are repeatedly raised about possible adverse respiratory effects of wearing filtering face pieces (FFP) during physical activity. This study compared the impact of FFP type 2 (NF95) on pulmonary function, blood gas values, metabolism and discomfort during light, moderate and vigorous physical activity. Healthy adults (n = 13; 6 females, 7 males; mean 31.3, SD 5.5 years) participated in this randomized two-armed (Ergometer cycling with a FFP type 2 vs. no mask) crossover trial. Baseline cardiopulmonary exercise testing and two interventions (masked and unmasked ergometer cycling 40%, 50% and 70% VO2max, 10 min each) were separated by 48 h washout periods. Spiroergometric data (End tidal carbon dioxide partial pressure PetCO2; breathing frequency; inspiration time), blood gas analysis outcomes (capillary carbon dioxide partial pressure, pCO2) and subjective response (Breathing effort and perceived exertion) were contrasted between conditions using ANOVAs. All participants completed the crossover trial, seven started with the FFP2 condition (No adverse events or side effects). FFP2 decreased breathing frequency, prolonged inspiration time, increased perceived breathing effort and PetCO2 (p < .05). Blood pCO2 in millimetres mercury increased during exercise with 50%VO2max (mean 36.67, SD 3.19 vs. mean 38.46, SD 2.57; p < .05) and 70%VO2max (35.04, 2.84 vs. 38.17, 3.43; p < .05) but not during exercise with 40%VO2max (36.55, 2.73 vs. 38.70). Perceived exertion was not affected (p > 0.05) by mask wearing. Conclusion: Mask-induced breathing resistance decreased respiratory performance and limited pulmonary gas exchange. While FFP2 affected subjective breathing effort per se, invasive diagnostics showed that statistically significant metabolic effects are induced from moderate intensity upwards. Trial registration: DRKS-ID: DRKS00030181, Date of registration: 05/09/2022 (German Register for Clinical Trials).

The End of the Formal Rehabilitation Is Not the End of Rehabilitation: Knee Function Deficits Remain After Anterior Cruciate Ligament Reconstruction.

OBJECTIVE: To rate athletes' functional ability and return to sport (RTS) success at the end of their individual, formal, medically prescribed rehabilitation after anterior anterior cruciate ligament (ACL) reconstruction. METHODS: In our prospective multicenter cohort study, 88 (42 females) adults aged 18-35 years after acute unilateral ACL rupture and subsequent hamstring grafting were included. All patients were prospectively monitored during their rehabilitation and RTS process until the end of their formal rehabilitation and RTS release. As outcome measures, functional hop and jump tests (front hop, balance hops, and drop jump screening test) and self-report outcomes (Knee Injury and Osteoarthritis Outcome Score, ACL-RTS after injury) were assessed. Literature-based cut-off values were selected to rate each performance as fulfilled or not. RESULTS: At 7.5 months (SD 2.3 months) after surgery, the percentage of participants meeting the functional thresholds ranged from 4% (Knee Injury and Osteoarthritis Outcome Score SPORT) and over 44% (ACL-RTS after injury sum score) to 59% (Knee Injury and Osteoarthritis Outcome Score activities of all daily living) in the self-report and from 29% (Balance side hop) to 69% (normalized knee separation distance) in performance testing. Only 4% fulfilled all the cut-offs, while 45% returned to the same type and level of sport. Participants who successfully returned to their previous sport (type and level) were more likely to be "over-cut-off-performers." CONCLUSIONS: The low share of the athletes who fulfilled the functional RTS criteria highlights the importance of continuing the rehabilitation measures after the formal completion to assess the need for and success of, inter alia, secondary-preventive therapies.

Do cool shirts make a difference? The effects of upper body garments on health, fluid balance and performance during exercise in the heat.

OBJECTIVES: Due to climate change and major sport events in hot climate, temperature regulation during exercise is gaining relevance in professional and amateur sports. This study compares the effects of an upper body garment with water-soaked inlays, of a synthetic- and of a cotton shirt on health, fluid balance and performance during a high intensity exercise session in the heat. METHODS: 32 healthy participants (age 25 ± 4 years; 15 women) were assigned to one of three upper body garments (cotton-shirt, synthetic-fiber-shirt, cooling-vest with water-soaked inlays) and underwent a high intensity steady state ergometer exercise test (Temperature 30.5 °C, frontal airflow 20 km/h, relative air-humidity 43 ± 13%). Time to exhaustion, physiologic parameters (inner ear temperature, heart rate, relative oxygen uptake, body weight, garment weight) and subjective data (perceived exertion, thermal sensation, skin wettedness, clothing humidity, feeling scale) were assessed. Time to exhaustion was analyzed using a survival time analysis. Other outcomes were evaluated using Kruskal-Wallis Tests and 95%-confidence-intervals. RESULTS: Time to exhaustion was not different between groups. Cooling-vests were heavier and led to lower inner ear temperature, lower thermal- and higher clothing-humidity-sensation at the start of exercise. Physiologic and subjective parameters showed no group differences at exercise termination. CONCLUSIONS: In a realistic setting including frontal airflow, synthetic and cotton-fiber shirts reach comparable effects on health and thermoregulation and are perceived as equally comfortable. Although inducing a small pre-exercise cooling effect, a water-soaked garment induces a weight penalty and creates a less comfortable situation.

Progressive daily hopping exercise improves running economy in amateur runners: a randomized and controlled trial.

This study investigated the effects of a daily plyometric hopping intervention on running economy (RE) in amateur runners. In a randomized, controlled trial, thirty-four amateur runners (29 ± 7 years, 27 males) were allocated to a control or a hopping exercise group. During the six-week study, the exercise group performed 5 min of double-legged hopping exercise daily. To progressively increase loading, the number of hopping bouts (10 s each) was steadily increased while break duration between sets was decreased. Pre- and post-intervention, RE, peak oxygen uptake (VO2peak), and respiratory exchange ratio (RER) were measured during 4-min stages at three running speeds (10, 12, and 14 km/h). ANCOVAs with baseline values and potential cofounders as cofactors were performed to identify differences between groups. ANCOVA revealed an effect of hopping on RE at 12 km/h (df = 1; F = 4.35; p < 0.05; η2 = 0.072) and 14 km/h (df = 1; F = 6.72; p < 0.05; η2 = 0.098), but not at 10 km/h (p > 0.05). Exercise did not affect VO2peak (p > 0.05), but increased RER at 12 km/h (df = 1; F = 4.26; p < 0.05; η2 = 0.059) and 14 km/h (df = 1; F = 36.73; p < 0.001; η2 = 0.520). No difference in RER was observed at 10 km/h (p > 0.05). Daily hopping exercise is effective in improving RE at high running speeds in amateurs and thus can be considered a feasible complementary training program.Clinical trial registration German Register of Clinical Trials (DRKS00017373).

After Dinner Rest a While, After Supper Walk a Mile? A Systematic Review with Meta-analysis on the Acute Postprandial Glycemic Response to Exercise Before and After Meal Ingestion in Healthy Subjects and Patients with Impaired Glucose Tolerance.

BACKGROUND: The most effective way to cope with high blood sugar spikes is to engage in physical activity in temporal proximity to food intake. However, so far, it is unclear as to whether there is an optimal time for physical activity around food intake. OBJECTIVES: We aimed to identify the impact of pre- and post-meal exercise on postprandial glucose excursions in humans with and without type 2 diabetes mellitus. METHODS: We conducted a systematic review with meta-analysis, PROSPERO registration number: CRD42022324070. We screened MEDLINE/PubMed, Cochrane/CINAHL/EMBASE, and Web of Knowledge until 1 May, 2022. We used the risk of bias rating with the crossover extension of the Cochrane risk of bias assessment tool II. Standardized mean differences (SMDs, Hedges' g) with 95% confidence intervals (CIs) were calculated as pooled effect estimates of a random-effects meta-analysis. Eligibility criteria included three-armed randomized controlled trials comparing the acute effects of pre- and post-meal exercise to a no-exercise control in humans. RESULTS: Eight randomized controlled trials (crossover trials, high risk of bias) with 30 interventions in 116 participants (47 diagnosed with type 2 diabetes, 69 without type 2 diabetes) were eligible. Exercise after meal ingestion (real food or meal replacement drinks) led to a reduction in postprandial glucose excursions compared with exercise before eating (15 effect sizes; SMD = 0.47 [95% CI 0.23, 0.70]) and an inactive control condition (15 effect sizes; SMD = 0.55 [95% CI 0.34, 0.75]. Pre-meal exercise did not lead to significantly lower postprandial glucose compared to an inactive control (15 effect sizes; SMD = - 0.13 [95% CI - 0.42, 0.17]). The time between meal and exercise (estimate = - 0.0151; standard error = 0.00473; Z = - 3.19; p = 0.001; 95% CI - 0.024, - 0.006) had a moderating influence on postprandial glucose excursions. CONCLUSIONS: Exercise, i.e., walking, has a greater acute beneficial impact on postprandial hyperglycemia when undertaken as soon as possible after a meal rather than after a longer interval or before eating. CLINICAL TRIAL REGISTRATION: The review was pre-registered in the PROSPERO database (CRD42022324070). The date of submission was 07.04.2022, with the registration on 08.05.2022.

Changes in miRNA expression in patients with peripheral arterial vascular disease during moderate- and vigorous-intensity physical activity.

BACKGROUND: Walking is the preferred therapy for peripheral arterial disease in early stage. An effect of walking exercise is the increase of blood flow and fluid shear stress, leading, triggered by arteriogenesis, to the formation of collateral blood vessels. Circulating micro-RNA may act as an important information transmitter in this process. We investigated the acute effects of a single bout of 1) aerobic walking with moderate intensity; and 2) anaerobic walking with vigorous intensity on miRNA parameters related to vascular collateral formation. METHODS: Ten (10) patients with peripheral arterial disease with claudication (age 72 ± 7 years) participated in this two-armed, randomized-balanced cross-over study. The intervention arms were single bouts of supervised walking training at (1) vigorous intensity on a treadmill up to volitional exhaustion and (2) moderate intensity with individual selected speed for a duration of 20 min. One week of washout was maintained between the arms. During each intervention, heart rate was continuously monitored. Acute effects on circulating miRNAs and lactate concentration were determined using pre- and post-intervention measurement comparisons. RESULTS: Vigorous-intensity walking resulted in a higher heart rate (125 ± 21 bpm) than the moderate-intensity intervention (88 ± 9 bpm) (p < 0.05). Lactate concentration was increased after vigorous-intensity walking (p = 0.005; 3.3 ± 1.2 mmol/l), but not after moderate exercising (p > 0.05; 1.7 ± 0.6 mmol/l). The circulating levels of miR-142-5p and miR-424-5p were up-regulated after moderate-intensity (p < 0.05), but not after vigorous-intensity training (p > 0.05). CONCLUSION: Moderate-intensity walking seems to be more feasible than vigorous exercises to induce changes of blood flow and endurance training-related miRNAs in patients with peripheral arterial disease. Our data thus indicates that effect mechanisms might follow an optimal rather than a maximal dose response relation. Steady state walking without the necessity to reach exhaustion seems to be better suited as stimulus.

Cortical Motor Planning and Biomechanical Stability During Unplanned Jump Landings in Men With Anterior Cruciate Ligament Reconstruction.

CONTEXT: Athletes with anterior cruciate ligament (ACL) reconstruction (ACLR) exhibit increased cortical motor planning during simple sensorimotor tasks compared with healthy athletes serving as control groups. This may interfere with proper decision making during time-constrained movements, elevating the reinjury risk. OBJECTIVE: To compare cortical motor planning and biomechanical stability during jump landings between participants with ACLR and healthy individuals. DESIGN: Cross-sectional study. SETTING: Laboratory. PATIENTS OR OTHER PARTICIPANTS: Ten men with ACLR (age = 28 ± 4 years, time after surgery = 63 ± 35 months) and 17 healthy men (age = 28 ± 4 years) completed 43 ± 4 preplanned (landing leg shown before takeoff) and 51 ± 5 unplanned (visual cue during flight) countermovement jumps with single-legged landings. MAIN OUTCOME MEASURE(S): Movement-related cortical potentials (MRCPs) and frontal θ frequency power before the jump were analyzed using electroencephalography. Movement-related cortical potentials were subdivided into 3 successive 0.5-second time periods (readiness potential [RP]-1, RP-2, and negative slope [NS]) relative to movement onset, with higher values indicating more motor planning. Theta power was calculated for the last 0.5 second before movement onset, with higher values demonstrating more focused attention. Biomechanical landing stability was measured via peak vertical ground reaction force, time to stabilization, and center of pressure. RESULTS: Both the ACLR and healthy groups evoked MRCPs at all 3 time periods. During the unplanned task analyzed using P values and Cohen d, the ACLR group exhibited slightly higher but not different MRCPs, achieving medium effect sizes (RP-1: P = .25, d = 0.44; RP-2: P = .20, d = 0.53; NS: P = .28, d = 0.47). The ACLR group also showed slightly higher θ power values that were not different during the preplanned (P = .18, d = 0.29) or unplanned (P = .42, d = 0.07) condition, achieving small effect sizes. The groups did not differ in their biomechanical outcomes (P values > .05). No condition × group interactions occurred (P values > .05). CONCLUSIONS: Our jump-landing task evoked MRCPs. Although not different between groups, the observed effect sizes provided the first indication that men with ACLR might have consistently relied on more cortical motor planning associated with unplanned jump landings. Confirmatory studies with larger sample sizes are warranted.

Blood gas levels, cardiovascular strain and cognitive performance during surgical mask and filtering face piece application.

Mask induced airway resistance and carbon dioxide rebreathing is discussed to impact gas exchange and to induce discomfort and impairments in cognitive performance. N = 23 healthy humans (13 females, 10 males; 23.5 ± 2.1 years) participated in this randomized crossover trial (3 arms, 48-h washout periods). During interventions participants wore either a surgical face mask (SM), a filtering face piece (FFP2) or no mask (NM). Interventions included a 20-min siting period and 20 min steady state cycling on an ergometer at 77% of the maximal heart rate (HR). Hemodynamic data (HR, blood pressure), metabolic outcomes (pulse derived oxygen saturation, capillary carbon dioxide (pCO2), and oxygen partial pressure (pO2), lactate, pH, base excess), subjective response (ability to concentrate, arousal, perceived exertion) and cognitive performance (Stroop Test) were assessed. Compared to NM, both masks increased pCO2 (NM 31.9 ± 3.3 mmHg, SM = 35.2 ± 4.0 mmHg, FFP2 = 34.5 ± 3.8 mmHg, F = 12.670, p < 0.001) and decreased pH (NM = 7.42 ± 0.03, SM = 7.39 ± 0.03, FFP2 = 7.39 ± 0.04, F = 11.4, p < 0.001) during exercise. The FFP2 increased blood pressure during exercise (NM = 158 ± 15 mmHg, SM = 159 ± 16 mmHg, FFP2 = 162 ± 17 mmHg, F = 3.21, p = 0.050), the SM increased HR during sitting (NM = 70 ± 8 bpm, SM = 74 ± 8 bpm, FFP2 = 73 ± 8 bpm, F = 4.70, p = 0.014). No mask showed any comparative effect on other hemodynamic, metabolic, subjective, or cognitive outcomes. Mask wearing leads to slightly increased cardiovascular stress and elevated carbon dioxide levels during exercise but did not affect cognitive performance or wellbeing.

The Acute Effects of Single or Repeated Bouts of Vigorous-Intensity Exercise on Insulin and Glucose Metabolism during Postprandial Sedentary Behavior.

Fitness and exercise may counteract the detrimental metabolic and mood adaptations during prolonged sitting. This study distinguishes the immediate effects of a single bout vs. work-load and intensity-matched repeated exercise breaks on subjective well-being, blood glucose, and insulin response (analyzed as area under the curve) during sedentary time; and assesses the influence of fitness and caloric intake on metabolic alterations during sedentariness. Eighteen women underwent cardiopulmonary exercise testing and three 4 h sitting interventions: two exercise interventions (70% VO2max, 30 min, cycle ergometer: (1) cycling prior to sitting; (2) sitting interrupted by 5 × 6 min cycling), and one control condition (sitting). Participants consumed one meal with ad libitum quantity (caloric intake), but standardized macronutrient proportion. Exercise breaks (4057 ± 2079 µU/mL·min) reduced insulin values compared to a single bout of exercise (5346 ± 5000 µU/mL·min) and the control condition (6037 ± 3571 µU/mL·min) (p ≤ 0.05). ANCOVA revealed moderating effects of caloric intake (519 ± 211 kilocalories) (p ≤ 0.01), but no effects of cardiorespiratory fitness (41.3 ± 4.2 mL/kg/min). Breaks also led to lower depression, but higher arousal compared to a no exercise control (p ≤ 0.05). Both exercise trials led to decreased agitation (p ≤ 0.05). Exercise prior to sitting led to greater peace of mind during sedentary behavior (p ≤ 0.05). Just being fit or exercising prior to sedentary behavior are not feasible to cope with acute detrimental metabolic changes during sedentary behavior. Exercise breaks reduce the insulin response to a meal. Despite their vigorous intensity, breaks are perceived as positive stimulus. Detrimental metabolic changes during sedentary time could also be minimized by limiting caloric intake.

The impact of regular activity and exercise intensity on the acute effects of resistance exercise on cognitive function.

Beneficial acute effects of resistance exercise on cognitive functions may be modified by exercise intensity or by habitual physical activity. Twenty-six participants (9 female and 17 male; 25.5 ± 3.4 years) completed four resistance exercise interventions in a randomized order on separate days (≥48 h washout). The intensities were set at 60%, 75%, and 90% of the one repetition maximum (1RM). Three interventions had matched workloads (equal resistance*nrepetitions ). One intervention applied 75% of the 1RM and a 50% reduced workload (resistance*nrepetitions  = 50%). Cognitive attention (Trail Making Test A-TMTA), task switching (Trail Making Test B-TMTB), and working memory (Digit Reading Spans Backward) were assessed before and immediately after exercise. Habitual activity was assessed as MET hours per week using the International Physical Activity Questionnaire. TMTB time to completion was significantly shorter after exercise with an intensity of 60% 1RM and 75% 1RM and 100% workload. Friedman test indicated a significant effect of exercise intensity in favor of 60% 1RM. TMTA performance was significantly shorter after exercise with an intensity of 60% 1RM, 90% 1RM, and 75% 1RM (50% workload). Habitual activity with vigorous intensity correlated positively with the baseline TMTB and Digit Span Forward performance but not with pre- to post-intervention changes. Task switching, based on working memory, mental flexibility, and inhibition, was beneficially influenced by acute exercise with moderate intensity whereas attention performance was increased after exercise with moderate and vigorous intensity. The effect of regular activity had no impact on acute exercise effects.

The Impact of Ubiquitous Face Masks and Filtering Face Piece Application During Rest, Work and Exercise on Gas Exchange, Pulmonary Function and Physical Performance: A Systematic Review with Meta-analysis.

BACKGROUND: Protection against airborne infection is currently, due to the COVID-19-associated restrictions, ubiquitously applied during public transport use, work and leisure time. Increased carbon dioxide re-inhalation and breathing resistance may result thereof and, in turn, may negatively impact metabolism and performance. OBJECTIVES: To deduce the impact of the surgical mask and filtering face piece type 2 (FFP2) or N95 respirator application on gas exchange (pulse-derived oxygen saturation (SpO2), carbon dioxide partial pressure (PCO2), carbon dioxide exhalation (VCO2) and oxygen uptake (VO2)), pulmonary function (respiratory rate and ventilation) and physical performance (heart rate HR, peak power output Wpeak). METHODS: Systematic review with meta-analysis. Literature available in Medline/Pubmed, the Cochrane Library and the Web of Knowledge with the last search on the 6th of May 2021. Eligibility criteria: Randomised controlled parallel group or crossover trials (RCT), full-text availability, comparison of the acute effects of ≥ 1 intervention (surgical mask or FFP2/N95 application) to a control/comparator condition (i.e. no mask wearing). Participants were required to be healthy humans and > 16 years of age without conditions or illnesses influencing pulmonary function or metabolism. Risk of bias was rated using the crossover extension of the Cochrane risk of bias assessment tool II. Standardised mean differences (SMD, Hedges' g) with 95% confidence intervals (CI) were calculated, overall and for subgroups based on mask and exercise type, as pooled effect size estimators in our random-effects meta-analysis. RESULTS: Of the 1499 records retrieved, 14 RCTs (all crossover trials, high risk of bias) with 25 independent intervention arms (effect sizes per outcome) on 246 participants were included. Masks led to a decrease in SpO2 during vigorous intensity exercise (6 effect sizes; SMD = - 0.40 [95% CI: - 0.70, - 0.09], mostly attributed to FFP2/N95) and to a SpO2-increase during rest (5 effect sizes; SMD = 0.34 [95% CI: 0.04, 0.64]); no general effect of mask wearing on SpO2 occurred (21 effect sizes, SMD = 0.34 [95% CI: 0.04, 0.64]). Wearing a mask led to a general oxygen uptake decrease (5 effect sizes, SMD = - 0.44 [95% CI: - 0.75, - 0.14]), to slower respiratory rates (15 effect sizes, SMD = - 0.25 [95% CI: - 0.44, - 0.06]) and to a decreased ventilation (11 effect sizes, SMD = - 0.43 [95% CI: - 0.74, - 0.12]). Heart rate (25 effect sizes; SMD = 0.05 [95% CI: - 0.09, 0.19]), Wpeak (9 effect sizes; SMD = - 0.12 [95% CI: - 0.39, 0.15]), PCO2 (11 effect sizes; SMD = 0.07 [95% CI: - 0.14, 0.29]) and VCO2 (4 effect sizes, SMD = - 0.30 [95% CI: - 0.71, 0.10]) were not different to the control, either in total or dependent on mask type or physical activity status. CONCLUSION: The number of crossover-RCT studies was low and the designs displayed a high risk of bias. The within-mask- and -intensity-homogeneous effects on gas exchange kinetics indicated larger detrimental effects during exhausting physical activities. Pulse-derived oxygen saturation was increased during rest when a mask was applied, whereas wearing a mask during exhausting exercise led to decreased oxygen saturation. Breathing frequency and ventilation adaptations were not related to exercise intensity. FFP2/N95 and, to a lesser extent, surgical mask application negatively impacted the capacity for gas exchange and pulmonary function but not the peak physical performance. Registration: Prospero registration number: CRD42021244634.

The age-related decline in spatiotemporal gait characteristics is moderated by concerns of falling, history of falls & diseases, and sociodemographic-anthropometric characteristics in 60-94 years old adults.

BACKGROUND: Associations between age, concerns or history of falling, and various gait parameters are evident. Limited research, however, exists on how such variables moderate the age-related decline in gait characteristics. The purpose of the present study was to investigate the moderating effects of concerns of falling (formerly referred to as fear of falling), history of falls & diseases, and sociodemographic characteristics on changes in gait characteristics with increasing age in the elderly. METHODS: In this individual participant level data re-analysis, data from 198 participants (n = 125 females) from 60 to 94 years of age were analysed (mean 73.9, standard deviation 7.7 years). Dependent variables were major spatiotemporal gait characteristics, assessed using a capacitive force measurement platform (zebris FDM-T). Age (independent variable) and the moderating variables concerns of falling (FES-I), gender/sex, history of falls and fall-related medical records, number of drugs daily taken, and body mass index were used in the statistical analysis. Hierarchical linear mixed moderation models (multilevel analysis) with stepwise (forward) modelling were performed. RESULTS: Decreases of gait speed (estimate = -.03, equals a decrease of 0.03 m/s per year of ageing), absolute (- 1.4) and gait speed-normalized (-.52) stride length, step width (-.08), as well as increases in speed normalized cadence (.65) and gait speed variability (.15) are all age-related (each p < .05). Overall and specific situation-related concerns of falling (estimates: -.0012 to -.07) were significant moderators. History of potentially gait- and/or falls-affecting diseases accelerated the age-related decline in gait speed (-.002) and its variability (.03). History of falls was, although non-significant, a relevant moderator (in view of increasing the model fit) for cadence (.058) and gait speed (-.0027). Sociodemographics and anthropometrics showed further moderating effects (sex moderated the ageing effect on stride length, .08; height moderated the effect on the normalised stride length, .26; BMI moderated the effects on step width, .003). . CONCLUSION: Age-related decline in spatiotemporal gait characteristics is moderated by concerns of falling, (non-significantly) by history of falls, significantly by history of diseases, and sociodemographic characteristics in 60-94 years old adults. Knowing the interactive contributions to gait impairments could be helpful for tailoring interventions for the prevention of falls. TRIAL REGISTRATION: Re-analysis of [21-24].

Effects of Open Skill Visuomotor Choice Reaction Time Training on Unanticipated Jump-Landing Stability and Quality: A Randomized Controlled Trial.

Adapting movements rapidly to unanticipated external stimuli is paramount for athletic performance and to prevent injuries. We investigated the effects of a 4-week open-skill choice-reaction training intervention on unanticipated jump-landings. Physically active adults (n = 37; mean age 27, standard deviation 2.7 years, 16 females, 21 males) were randomly allocated to one of two interventions or a control group (CG). Participants in the two intervention groups performed a 4-week visuomotor open skill choice reaction training, one for the upper and one for the lower extremities. Before and after the intervention, two different types of countermovement jumps with landings in split stance position were performed. In the (1) pre-planned condition, we informed the participants regarding the landing position (left or right foot in front position) before the jump. In the (2) unanticipated condition, this information was displayed after take-off (350-600 ms reaction time before landing). Outcomes were landing stability [peak vertical ground reaction force (pGRF) and time to stabilization (TTS)], and landing-related decision-making quality (measured by the number of landing errors). To measure extremity-specific effects, we documented the number of correct hits during the trained drills. A two-factorial (four repeated measures: two conditions, two time factors; three groups) ANCOVA was carried out; conditions = unanticipated versus pre-planned condition, time factors = pre versus post measurement, grouping variable = intervention allocation, co-variates = jumping time and self-report arousal. The training improved performance over the intervention period (upper extremity group: mean of correct choice reaction hits during 5 s drill: +3.0 hits, 95% confidence interval: 2.2-3.9 hits; lower extremity group: +1.6 hits, 0.6-2.6 hits). For pGRF (F = 8.4, p < 0.001) and landing errors (F = 17.1, p < 0.001) repeated measures effect occurred. Significantly more landing errors occurred within the unanticipated condition for all groups and measurement days. The effect in pGRF is mostly impacted by between-condition differences in the CG. No between-group or interaction effect was seen for these outcomes: pGRF (F = 0.4, p = 0.9; F = 2.3, p = 0.1) landing errors (F = 0.5, p = 0.6; F = 2.3, p = 0.1). TTS displayed a repeated measures (F = 4.9, p < 0.001, worse values under the unanticipated condition, improvement over time) and an interaction effect (F = 2.4, p = 0.03). Healthy adults can improve their choice reaction task performance by training. As almost no transfer to unanticipated landing successfulness or movement quality occurred, the effect seems to be task-specific. Lower-extremity reactions to unanticipated stimuli may be improved by more specific training regimens.

Effects of single bouts of different endurance exercises with different intensities on microRNA biomarkers with and without blood flow restriction: a three-arm, randomized crossover trial.

PURPOSE: Physical activity is associated with altered levels of circulating microRNAs (ci-miRNAs). Changes in miRNA expression have great potential to modulate biological pathways of skeletal muscle hypertrophy and metabolism. This study was designed to determine whether the profile of ci-miRNAs is altered after different approaches of endurance exercise. METHODS: Eighteen healthy volunteers (aged 24 ± 3 years) participated this three-arm, randomized-balanced crossover study. Each arm was a single bout of treadmill-based acute endurance exercise at (1) 100% of the individual anaerobic threshold (IANS), (2) at 80% of the IANS and (3) at 80% of the IANS with blood flow restriction (BFR). Load-associated outcomes (fatigue, feeling, heart rate, and exhaustion) as well as acute effects (circulating miRNA patterns and lactate) were determined. RESULTS: All training interventions increased the lactate concentration (LC) and heart rate (HR) (p < 0.001). The high-intensity intervention (HI) resulted in a higher LC than both lower intensity protocols (p < 0.001). The low-intensity blood flow restriction (LI-BFR) protocol led to a higher HR and higher LC than the low-intensity (LI) protocol without BFR (p = 0.037 and p = 0.003). The level of miR-142-5p and miR-197-3p were up-regulated in both interventions without BFR (p < 0.05). After LI exercise, the expression of miR-342-3p was up-regulated (p = 0.038). In LI-BFR, the level of miR-342-3p and miR-424-5p was confirmed to be up-regulated (p < 0.05). Three miRNAs and LC show a significant negative correlation (miR-99a-5p, p = 0.011, r = - 0.343/miR-199a-3p, p = 0.045, r = - 0.274/miR-125b-5p, p = 0.026, r = - 0.302). Two partial correlations (intervention partialized) showed a systematic impact of the type of exercise (LI-BFR vs. HI) (miR-99a-59: r = - 0.280/miR-199a-3p: r = - 0.293). CONCLUSION: MiRNA expression patterns differ according to type of activity. We concluded that not only the intensity of the exercise (LC) is decisive for the release of circulating miRNAs-as essential is the type of training and the oxygen supply.

Physical activity, physical self-perception and depression symptoms in patients with major depressive disorder: a mediation analysis.

Physical inactivity is discussed as one of the most detrimental influences for lifestyle-related medical complications such as obesity, heart disease, hypertension, diabetes and premature mortality in in- and outpatients with major depressive disorder (MDD). In contrast, intervention studies indicate that moderate-to-vigorous-intensity physical activity (MVPA) might reduce complications and depression symptoms itself. Self-reported data on depression [Beck-Depression-Inventory-II (BDI-II)], general habitual well-being (FAHW), self-esteem and physical self-perception (FAHW, MSWS) were administrated in a cross-sectional study with 76 in- and outpatients with MDD. MVPA was documented using ActiGraph wGT3X + ® accelerometers and fitness was measured using cardiopulmonary exercise testing (CPET). Subgroups were built according to activity level (low PA defined as MVPA < 30 min/day, moderate PA defined as MVPA 30-45 min/day, high PA defined as MVPA > 45 min/day). Statistical analysis was performed using a Mann-Whitney U and Kruskal-Wallis test, Spearman correlation and mediation analysis. BDI-II scores and MVPA values of in- and outpatients were comparable, but fitness differed between the two groups. Analysis of the outpatient group showed a negative correlation between BDI-II and MVPA. No association of inpatient MVPA and psychopathology was found. General habitual well-being and self-esteem mediated the relationship between outpatient MVPA and BDI-II. The level of depression determined by the BDI-II score was significantly higher in the outpatient low- and moderate PA subgroups compared to outpatients with high PA. Fitness showed no association to depression symptoms or well-being. To ameliorate depressive symptoms of MDD outpatients, intervention strategies should promote habitual MVPA and exercise exceeding the duration recommended for general health (≥ 30 min/day). Further studies need to investigate sufficient MVPA strategies to impact MDD symptoms in inpatient settings. Exercise effects seem to be driven by changes of well-being rather than increased physical fitness.

Increased visual distraction can impair landing biomechanics.

Failed jump landings represent a key mechanism of musculoskeletal trauma. It has been speculated that cognitive dual-task loading during the flight phase may moderate the injury risk. This study aimed to explore whether increased visual distraction can compromise landing biomechanics. Twenty-one healthy, physically active participants (15 females, 25.8 ± 0.4 years) completed a series of 30 counter-movement jumps (CMJ) onto a capacitive pressure platform. In addition to safely landing on one leg, they were required to memorize either one, two or three jersey numbers shown during the flight phase (randomly selected and equally balanced over all jumps). Outcomes included the number of recall errors as well as landing errors and three variables of landing kinetics (time to stabilization/TTS, peak ground reaction force/pGRF, length of the centre of pressure trace/COPT). Differences between the conditions were calculated using the Friedman test and the post hoc Bonferroni-Holm corrected Wilcoxon test. Regardless of the condition, landing errors remained unchanged (p = .46). In contrast, increased visual distraction resulted in a higher number of recall errors (chi2 = 13.3, p = .001). Higher cognitive loading, furthermore, appeared to negatively impact mediolateral COPT (p < .05). Time to stabilization (p = .84) and pGRF (p = .78) were unaffected. A simple visual distraction in a controlled experimental setting is sufficient to adversely affect landing stability and task-related short-term memory during CMJ. The ability to precisely perceive the environment during movement under time constraints may, hence, represent a new injury risk factor and should be investigated in a prospective trial.

Deducing the Impact of Physical Activity, Sedentary Behavior, and Physical Performance on Cognitive Function in Healthy Older Adults.

Objectives: Participating in physical activity and maintaining physical performance as well as reducing sedentary behavior are discussed to be beneficially associated with cognitive function in older adults. The purpose of this cross-sectional analysis was to differentiate the relevance of objectively measured physical activity, physical performance, and sedentary behavior on cognitive function in healthy older adults (n = 56, age = 76 ± 7 yrs, gender = 30 female). Methods: Accelerometer based physical activity and sedentary behavior were analyzed as minutes per week spent sedentary and physically active with light or moderate to vigorous intensity. Participants' physical performance was assessed via cardiopulmonary exercise testing and analyzed as maximal workload and heart rate, heart rate reserve and peak oxygen uptake. The assessment of cognitive function included working memory, attention, executive function, and verbal memory. Data was analyzed with Spearman and partial correlations. Trial registration: NCT02343029. Results: Light physical activity was moderately associated with executive function (r = -0.339, p = 0.015). Attention was significantly associated with maximal workload (r = -0.286, p = 0.042) and peak oxygen uptake (r = -0.337, p = 0.015). Working memory was associated with maximal workload (r = 0.329, p = 0.017). Conclusion: Whereas a broad range of cognitive function were beneficially linked to physical performance, light intensity activities in particular showed an impact on executive function. Our research underlines the need to separate the impact of physical performance and physical activity on cognitive function and highlights the relevance of light physical activity.

Lower Extremity Open Skill Training Effects on Perception of Visual Stimuli, Cognitive Processing, and Performance.

This study investigates if lower extremity open-skill training impacts perception and cognitive processing abilities or just influences task related motor abilities. Twenty-two participants (24.7 ± 2.4years; 11 males, 11 females) were randomly allocated either into the group that trained on a computerized device or to the control group. Prior to and following the 4-week study period, motor performance was assessed using drop jump, hexagon test, postural control and lower extremity choice reaction. Perception, cognitive processing and task inhibition were captured using validated neurocognitive tests. Repeated measurements analyses of co-variances (ANCOVAs) were performed. They revealed a time (before and after intervention) × group (training vs. control) effect on lower extremity choice reaction and hexagon (p < .05). No effects on group differences or between groups in cognitive performance were found. A detrimental effect of training on accuracy of task inhibition (lower percentage of correct inhibitions) was detected. Computerized open skill training affects specific movement patterns without increasing task-relevant cognitive or perceptual abilities. Indicated by the lower percentage of correct inhibitions, the training might further detrimentally influence the risk-taking behavior during choice reaction tasks.

Acute Effects of Aerobic Exercise on Cognitive Attention and Memory Performance: An Investigation on Duration-Based Dose-Response Relations and the Impact of Increased Arousal Levels.

Current evidence indicates that acute aerobic exercise might increase domain-specific cognitive performance. However, only a small number of studies deduced the impact on lower and higher cognitive functions systematically or analyzed dose-response relationships and the underlying mechanisms. This study aimed to expose the dose-response relationships by investigating the influence of exercise duration on subjective and objective arousal, cognitive attention and visual recognition memory tasks. Nineteen participants (eight female; 25.69 ± 3.11 years) were included in a randomized, three-armed intervention study in a cross-over design. The participants completed three different interventions consisting of either 15, 30 or 45 min of cycling at 60-70% VO2max. Arousal and cognitive measurements were taken before and immediately after (<2 min) exercise. All three interventions led to significant but comparable effects on self-perceived arousal, heart rate (HR) and rating of perceived exertion (RPE) (p < 0.05). Analysis of variance (ANOVA) indicated significant effects of exercise duration on visual recognition memory accuracy. Reaction times for higher and lower cognitive tasks did not change after exercise. Fifteen minutes of aerobic exercise was feasible to induce beneficial changes in self-perceived arousal. Processing speed of visual recognition memory and attention remained unaltered. Exercise exceeding fifteen minutes seemed to negatively impact visual recognition memory accuracy.

Injury Profile of Hip-Hop Dancers.

This study assessed the injury incidence, mechanisms, and associated potential risk factors for hip-hop, popping, locking, house, and breaking dance styles. Data were collected from June to November 2015. The retrospective cohort study included 146 dancers (female: N = 67; age = 20 ± 4.2 years; males: N = 79; age = 22.9 ± 5.8 years) who completed a questionnaire that collected data concerning training hours, injuries, self-reported injury causes, treatment, and recovery time over the last 5 years. For the last 5 years, 52% (N = 76) of the dancers reported 159 injuries and, in the year prior to the survey, 31.5% (N = 46) reported a total of 75 injuries. Overall, 0.61 injuries (5 years) and 1.156 injuries (1 year) per 1,000 hours exposure time occurred. For breaking, 1.286 injuries (5 years) and 2.456 injuries (1 year) per 1,000 hours exposure time were calculated, while the other dance styles accumulatively reached 0.151 injuries (5 years) and 0.318 injuries (1 year) per 1,000 hours of exposure time. Breakers reported most injuries at the upper extremities, followed by the lower extremities, trunk, and head and neck region. Most injuries in hip-hop occurred at the lower extremities, mainly affecting the knees, followed by groin and ankle. Injuries experienced by popping and locking dancers only involved the lower extremities. In house, the lower extremities were affected most frequently, followed by the trunk. A total of 65.3% of the dancers experienced time loss, with a duration of 12.7 ± 21.3 weeks. Breakers experience significantly more injuries than dancers of the other styles. Injury risk among dancers of all the styles studied can be considered low compared to soccer players, swimmers, and long-distance runners.