Control of blood pressure in the cold: differentiation of skin and skeletal muscle vascular resistance.

NEW FINDINGS: What is the central question of this study? Why does blood pressure increases during cold air exposure? Specifically, what is the contribution of skin and skeletal muscle vascular resistance during whole body versus isolated face cooling? What is the main finding and its importance? Whole-body cooling caused an increase in blood pressure through an increase in skeletal muscle and cutaneous vascular resistance. However, isolated mild face cooling caused an increase in blood pressure predominately via an increase in cutaneous vasoconstriction. ABSTRACT: The primary aim of this investigation was to determine the individual contribution of the cutaneous and skeletal muscle circulations to the cold-induced pressor response. To address this, we examined local vascular resistances in the cutaneous and skeletal muscle of the arm and leg. Thirty-four healthy individuals underwent three different protocols, whereby cold air to clamp skin temperature (27°C) was passed over (1) the whole-body, (2) the whole-body, but with the forearm pre-cooled to clamp cutaneous vascular resistance, and (3) the face. Cold exposure applied to the whole body or isolated to the face increased mean arterial pressure (all, P < 0.001) and total peripheral resistance (all, P < 0.047) compared to thermal neutral baseline. Whole-body cooling increased femoral (P < 0.005) and brachial artery resistance (P < 0.003) compared to thermoneutral baseline. Moreover, when the forearm was pre-cooled to remove the contribution of cutaneous resistance (P = 0.991), there was a further increase in lower arm vasoconstriction (P = 0.036) when whole-body cooling was superimposed. Face cooling also caused a reflex increase in lower arm cutaneous (P = 0.009) and brachial resistance (P = 0.050), yet there was no change in femoral resistance (P = 0.815) despite a reflex increase in leg cutaneous resistance (P = 0.010). Cold stress causes an increase in blood pressure through a change in total peripheral resistance that is largely due to cutaneous vasoconstriction with face cooling, but there is additional vasoconstriction in the skeletal muscle vasculature with whole-body cooling.

The impact of leg position on muscle blood flow and oxygenation during low-intensity rhythmic plantarflexion exercise.

PURPOSE: Resistance training (RT) is an effective countermeasure to combat physical deconditioning whereby localized hypoxia within the limb increases metabolic stress eliciting muscle adaptation. The current study sought to examine the influence of gravity on muscle oxygenation (SmO2) alongside vascular hemodynamic responses. METHODS: In twelve young healthy adults, an ischemic occlusion test and seven minutes of low-intensity rhythmic plantarflexion exercise were used alongside superficial femoral blood flow and calf near-infrared spectroscopy to assess the microvascular vasodilator response, conduit artery flow-mediated dilation, exercise-induced hyperemia, and SmO2 with the leg positioned above or below the heart in a randomized order. RESULTS: The microvascular vasodilator response, assessed by peak blood flow (798 ± 231 mL/min vs. 1348 ± 290 mL/min; p < 0.001) and reperfusion slope 10 s of SmO2 after cuff deflation (0.75 ± 0.45%.s-1 vs.2.40 ± 0.94%.s-1; p < 0.001), was attenuated with the leg above the heart. This caused a blunted dilatation of the superficial femoral artery (3.0 ± 2.4% vs. 5.2 ± 2.1%; p = 0.008). Meanwhile, blood flow area under the curve was comparable (above the heart: 445 ± 147 mL vs. below the heart: 474 ± 118 mL; p = 0.55) in both leg positions. During rhythmic exercise, the increase in femoral blood flow was lower in the leg up position (above the heart: 201 ± 94% vs. below the heart: 292 ± 114%; p = 0.001) and contributed to a lower SmO2 (above the heart: 41 ± 18% vs. below the heart 67 ± 5%; p < 0.001). CONCLUSION: Positioning the leg above the heart results in attenuated peak vascular dilator response and exercise-induced hyperemia that coincided with a lower SmO2 during low-intensity plantarflexion exercise.

Global Reach 2018: sympathetic neural and hemodynamic responses to submaximal exercise in Andeans with and without chronic mountain sickness.

Andeans with chronic mountain sickness (CMS) and polycythemia have similar maximal oxygen uptakes to healthy Andeans. Therefore, this study aimed to explore potential adaptations in convective oxygen transport, with a specific focus on sympathetically mediated vasoconstriction of nonactive skeletal muscle. In Andeans with (CMS+, n = 7) and without (CMS-, n = 9) CMS, we measured components of convective oxygen delivery, hemodynamic (arterial blood pressure via intra-arterial catheter), and autonomic responses [muscle sympathetic nerve activity (MSNA)] at rest and during steady-state submaximal cycling exercise [30% and 60% peak power output (PPO) for 5 min each]. Cycling caused similar increases in heart rate, cardiac output, and oxygen delivery at both workloads between both Andean groups. However, at 60% PPO, CMS+ had a blunted reduction in Δtotal peripheral resistance (CMS-, -10.7 ± 3.8 vs. CMS+, -4.9 ± 4.1 mmHg·L-1·min-1; P = 0.012; d = 1.5) that coincided with a greater Δforearm vasoconstriction (CMS-, -0.2 ± 0.6 vs. CMS+, 1.5 ± 1.3 mmHg·mL-1·min-1; P = 0.008; d = 1.7) and a rise in Δdiastolic blood pressure (CMS-, 14.2 ± 7.2 vs. CMS+, 21.6 ± 4.2 mmHg; P = 0.023; d = 1.2) compared with CMS-. Interestingly, although MSNA burst frequency did not change at 30% or 60% of PPO in either group, at 60% Δburst incidence was attenuated in CMS+ (P = 0.028; d = 1.4). These findings indicate that in Andeans with polycythemia, light intensity exercise elicited similar cardiovascular and autonomic responses compared with CMS-. Furthermore, convective oxygen delivery is maintained during moderate-intensity exercise despite higher peripheral resistance. In addition, the elevated peripheral resistance during exercise was not mediated by greater sympathetic neural outflow, thus other neural and/or nonneural factors are perhaps involved.NEW & NOTEWORTHY During submaximal exercise, convective oxygen transport is maintained in Andeans suffering from polycythemia. Light intensity exercise elicited similar cardiovascular and autonomic responses compared with healthy Andeans. However, during moderate-intensity exercise, we observed a blunted reduction in total peripheral resistance, which cannot be ascribed to an exaggerated increase in muscle sympathetic nerve activity, indicating possible contributions from other neural and/or nonneural mechanisms.

Integrative crosstalk between hypoxia and the cold: Old data and new opportunities.

NEW FINDINGS: What is the topic of this review? The aim was to examine the influence of hypoxia on thermoregulatory and cardiovascular control in the cold. What advances does it highlight? Exposure to hypoxia seems to alter both thermoregulatory and cardiovascular control, but these conclusions are based on limited data, and this review highlights the need for future research in this area. ABSTRACT: Cold stress and hypoxia have been the subject of research for decades; however, humans often encounter these stressors together, such as in the alpine environment. Therefore, this review summarizes previous data with respect to the influence of hypoxia on thermoregulatory and cardiovascular control in the cold and presents new ideas for the future. Altogether, little to no evidence is available on the integrative and adaptive mechanisms by which the human body regulates heat conservation, oxygen delivery and maintenance of blood pressure.

Effects of Upper Body Exercise Training on Aerobic Fitness and Performance in Healthy People: A Systematic Review.

Purpose: This systematic review aimed to evaluate the effects of upper body endurance training (UBET) on oxygen uptake (VO2) in healthy persons and derive evidence-based recommendations to improve upper body fitness and performance. Methods: Databases were systematically searched in accordance with PRISMA guidelines until 1 February 2023. Eligibility criteria included healthy male and female adults and older adults who underwent an UBET intervention. Outcomes of interest included physical fitness (VO2peak and/ or VO2 submax) and transfer effects (i.e., effects from trained (VO2peak ARM) to untrained (VO2peak LEG) musculature). Results: The search identified 8293 records, out of which 27 studies reporting on 29 interventions met our eligibility criteria. The average duration of interventions was 6.8 ± 2.6 weeks with 3.2 ± 0.8 training sessions per week. For 21 of 29 interventions, significant increases in VO2peak ARM were reported following UBET (+16.4% ± 8.3%). Three of the nine studies that analyzed transfer effects of untrained legs after upper body training exhibited significant increases in VO2peak LEG (+9.3% ± 2.6%). Conclusions: This review showed that UBET is a beneficial and useful training modality to increase the oxygen utilization in the upper body. Although UBET is an uncommon form of endurance training in healthy individuals, transfer effects to the untrained muscles can be observed in isolated cases only, rendering transfer effects in UBET inconclusive. Further research should focus on the peripheral changes in muscle morphology of the trained muscles and central changes in cardiovascular function as well as when transfer effects can occur after UBET in healthy people.

Risk factors and injury prevention strategies for overuse injuries in adult climbers: a systematic review.

Introduction: Climbing is an increasingly popular activity and imposes specific physiological demands on the human body, which results in unique injury presentations. Of particular concern are overuse injuries (non-traumatic injuries). These injuries tend to present in the upper body and might be preventable with adequate knowledge of risk factors which could inform about injury prevention strategies. Research in this area has recently emerged but has yet to be synthesized comprehensively. Therefore, the aim of this study was to conduct a systematic review of the potential risk factors and injury prevention strategies for overuse injuries in adult climbers. Methods: This systematic review was conducted in accordance with the PRISMA guidelines. Databases were searched systematically, and articles were deemed eligible based upon specific criteria. Research included was original and peer-reviewed, involving climbers, and published in English, German or Czech. Outcomes included overuse injury, and at least one or more variable indicating potential risk factors or injury prevention strategies. The methodological quality of the included studies was assessed with the Downs and Black Quality Index. Data were extracted from included studies and reported descriptively for population, climbing sport type, study design, injury definition and incidence/prevalence, risk factors, and injury prevention strategies. Results: Out of 1,183 records, a total of 34 studies were included in the final analysis. Higher climbing intensity, bouldering, reduced grip/finger strength, use of a "crimp" grip, and previous injury were associated with an increased risk of overuse injury. Additionally, a strength training intervention prevented shoulder and elbow injuries. BMI/body weight, warm up/cool downs, stretching, taping and hydration were not associated with risk of overuse injury. The evidence for the risk factors of training volume, age/years of climbing experience, and sex was conflicting. Discussion: This review presents several risk factors which appear to increase the risk of overuse injury in climbers. Strength and conditioning, load management, and climbing technique could be targeted in injury prevention programs, to enhance the health and wellbeing of climbing athletes. Further research is required to investigate the conflicting findings reported across included studies, and to investigate the effectiveness of injury prevention programs. Systematic Review Registration: https://www.crd.york.ac.uk/, PROSPERO (CRD42023404031).

Biomechanics and lower limb function are altered in athletes and runners with achilles tendinopathy compared with healthy controls: A systematic review.

Achilles tendinopathy (AT) is a debilitating injury in athletes, especially for those engaged in repetitive stretch-shortening cycle activities. Clinical risk factors are numerous, but it has been suggested that altered biomechanics might be associated with AT. No systematic review has been conducted investigating these biomechanical alterations in specifically athletic populations. Therefore, the aim of this systematic review was to compare the lower-limb biomechanics of athletes with AT to athletically matched asymptomatic controls. Databases were searched for relevant studies investigating biomechanics during gait activities and other motor tasks such as hopping, isolated strength tasks, and reflex responses. Inclusion criteria for studies were an AT diagnosis in at least one group, cross-sectional or prospective data, at least one outcome comparing biomechanical data between an AT and healthy group, and athletic populations. Studies were excluded if patients had Achilles tendon rupture/surgery, participants reported injuries other than AT, and when only within-subject data was available.. Effect sizes (Cohen's d) with 95% confidence intervals were calculated for relevant outcomes. The initial search yielded 4,442 studies. After screening, twenty studies (775 total participants) were synthesised, reporting on a wide range of biomechanical outcomes. Females were under-represented and patients in the AT group were three years older on average. Biomechanical alterations were identified in some studies during running, hopping, jumping, strength tasks and reflex activity. Equally, several biomechanical variables studied were not associated with AT in included studies, indicating a conflicting picture. Kinematics in AT patients appeared to be altered in the lower limb, potentially indicating a pattern of "medial collapse". Muscular activity of the calf and hips was different between groups, whereby AT patients exhibited greater calf electromyographic amplitudes despite lower plantar flexor strength. Overall, dynamic maximal strength of the plantar flexors, and isometric strength of the hips might be reduced in the AT group. This systematic review reports on several biomechanical alterations in athletes with AT. With further research, these factors could potentially form treatment targets for clinicians, although clinical approaches should take other contributing health factors into account. The studies included were of low quality, and currently no solid conclusions can be drawn.

High-intensity exercise and passive hot water immersion cause similar postintervention changes in peripheral and cerebral shear.

Passive hot water immersion (PHWI) provides a peripheral vasculature shear stimulus comparable to low-intensity exercise within the active skeletal muscle, whereas moderate- and high-intensity exercise elicit substantially greater shear rates in the peripheral vasculature, likely conferring greater vascular benefits. Notably, few studies have compared postintervention shear rates in the peripheral and cerebral vasculature after high-intensity exercise and PHWI, especially considering that the postintervention recovery period represents a key window in which adaptation occurs. Therefore, we aimed to compare shear rates in the internal carotid artery (ICA), vertebral artery (VA), and common femoral artery (CFA) between high-intensity exercise and whole body PHWI for up to 80 min after intervention. Fifteen healthy (27 ± 4 yr), moderately trained individuals underwent three time-matched interventions in a randomized order that included 30 min of whole body immersion in a 42°C hot bath, 30 min of treadmill running and 5 × 4-min high-intensity intervals (HIIE). There were no differences in ICA (P = 0.4643) and VA (P = 0.1940) shear rates between PHWI and exercise (both continuous and HIIE) after intervention. All three interventions elicited comparable increases in CFA shear rate after intervention (P = 0.0671); however, CFA shear rate was slightly higher 40 min after threshold running (P = 0.0464) and slightly higher, although not statistically, for HIIE (P = 0.0565) compared with PHWI. Our results suggest that time- and core temperature-matched high-intensity exercise and PHWI elicit limited changes in cerebral shear and comparable increases in peripheral vasculature shear rates when measured for up to 80 min after intervention.NEW & NOTEWORTHY The study aimed to compare shear rates in lower limb and extracranial cerebral blood vessels for up to 80 min after high-intensity exercise and whole body passive hot water immersion (PHWI). Time- and core temperature-matched high-intensity exercise and whole body PHWI both elicited minimal, but comparable, postintervention changes in cerebral artery shear rate. Furthermore, 30 min of PHWI caused a postintervention increase in femoral shear rate similar to high-intensity exercise; however, femoral shear remained slightly elevated for a longer period after high-intensity exercise. These results suggest that PHWI provides postintervention changes in lower limb peripheral shear rates comparable to intense exercise and is likely a therapeutic alternative in individuals unable to perform exercise.

Assessment of Maximal Aerobic Capacity in Ski Mountaineering: A Laboratory-Based Study.

This study aims to evaluate the agreement in maximum oxygen consumption (V˙O2max) between a running protocol and a ski mountaineering (SKIMO) protocol. Eighteen (eleven males, seven females) ski mountaineers (age: 25 ± 3 years) participated in the study. V˙O2max, maximum heart rate (HRmax), and maximum blood lactate concentration (BLAmax) were determined in an incremental uphill running test and an incremental SKIMO-equipment-specific test. V˙O2max did not differ between the SKIMO and uphill running protocols (p = 0.927; mean difference -0.07 ± 3.3 mL/min/kg), nor did HRmax (p = 0.587, mean difference -0.7 ± 5.1 bpm). A significant correlation was found between V˙O2max SKIMO and V˙O2max running (p ≤ 0.001; ICC = 0.862 (95% CI: 0.670-0.946)). The coefficient of variation was 4.4% (95% CI: 3.3-6.5). BLAmax was significantly lower for SKIMO compared to running (12.0 ± 14.1%; p = 0.002). This study demonstrates that V˙O2max determined with a traditional uphill running protocol demonstrates good agreement with an equipment-specific SKIMO protocol.

Intra-rater reliability of leg blood flow during dynamic exercise using Doppler ultrasound.

Developing an exercise model that resembles a traditional form of aerobic exercise and facilitates a complete simultaneous assessment of multiple parameters within the oxygen cascade is critically for understanding exercise intolerances in diseased populations. Measurement of muscle blood flow is a crucial component of such a model and previous studies have used invasive procedures to determine blood flow kinetics; however, this may not be appropriate in certain populations. Furthermore, current models utilizing Doppler ultrasound use isolated limb exercise and while these studies have provided useful data, the exercise model does not mimic the whole-body physiological response to continuous dynamic exercise. Therefore, we aimed to measure common femoral artery blood flow using Doppler ultrasound during continuous dynamic stepping exercise performed at three independent workloads to assess the within day and between-day reliability for such an exercise modality. We report a within-session coefficient of variation of 5.8% from three combined workloads and a between-day coefficient of variation of 12.7%. These values demonstrate acceptable measurement accuracy and support our intention of utilizing this noninvasive exercise model for an integrative assessment of the whole-body physiological response to exercise in a range of populations.

Whole body passive heating versus dynamic lower body exercise: a comparison of peripheral hemodynamic profiles.

Passive heating has emerged as a therapeutic intervention for the treatment and prevention of cardiovascular disease. Like exercise, heating increases peripheral artery blood flow and shear rate, which is thought to be a primary mechanism underpinning endothelium-mediated vascular adaptation. However, few studies have compared the increase in arterial blood flow and shear rate between dynamic exercise and passive heating. In a fixed crossover design study, 15 moderately trained healthy participants (25.6 ± 3.4 yr) (5 female) underwent 30 min of whole body passive heating (42°C bath), followed on a separate day by 30 min of semi-recumbent stepping exercise performed at two workloads corresponding to the increase in cardiac output (Qc) (Δ3.72 L·min-1) and heart rate (HR) (Δ40 beats/min) recorded at the end of passive heating. At the same Qc (Δ3.72 L·min-1 vs. 3.78 L·min-1), femoral artery blood flow (1,599 mL/min vs. 1,947 mL/min) (P = 0.596) and shear rate (162 s-1 vs. 192 s-1) (P = 0.471) measured by ultrasonography were similar between passive heating and stepping exercise. However, for the same HRMATCHED intensity, femoral blood flow (1,599 mL·min-1 vs. 2,588 mL·min-1) and shear rate (161 s-1 vs. 271 s-1) were significantly greater during exercise, compared with heating (both P = <0.001). The results indicate that, for moderately trained individuals, passive heating increases common femoral artery blood flow and shear rate similar to low-intensity continuous dynamic exercise (29% V̇o2max); however, exercise performed at a higher intensity (53% V̇o2max) results in significantly larger shear rates toward the active skeletal muscle.NEW & NOTEWORTHY Passive heating and exercise increase blood flow through arteries, generating a frictional force, termed shear rate, which is associated with positive vascular health. Few studies have compared the increase in arterial blood flow and shear rate elicited by passive heating with that elicited by dynamic continuous exercise. We found that 30 min of whole body passive hot-water immersion (42°C bath) increased femoral artery blood flow and shear rate equivalent to exercising at a moderate intensity (∼57% HRmax).

Reducing intracranial pressure by reducing central venous pressure: assessment of potential countermeasures to spaceflight-associated neuro-ocular syndrome.

Spaceflight-associated neuro-ocular syndrome (SANS) involves unilateral or bilateral optic disc edema, widening of the optic nerve sheath, and posterior globe flattening. Owing to posterior globe flattening, it is hypothesized that microgravity causes a disproportionate change in intracranial pressure (ICP) relative to intraocular pressure. Countermeasures capable of reducing ICP include thigh cuffs and breathing against inspiratory resistance. Owing to the coupling of central venous pressure (CVP) and intracranial pressure, we hypothesized that both ICP and CVP will be reduced during both countermeasures. In four male participants (32 ± 13 yr) who were previously implanted with Ommaya reservoirs for treatment of unrelated clinical conditions, ICP was measured invasively through these ports. Subjects were healthy at the time of testing. CVP was measured invasively by a peripherally inserted central catheter. Participants breathed through an impedance threshold device (ITD, -7 cmH2O) to generate negative intrathoracic pressure for 5 min, and subsequently, wore bilateral thigh cuffs inflated to 30 mmHg for 2 min. Breathing through an ITD reduced both CVP (6 ± 2 vs. 3 ± 1 mmHg; P = 0.02) and ICP (16 ± 3 vs. 12 ± 1 mmHg; P = 0.04) compared to baseline, a result that was not observed during the free breathing condition (CVP, 6 ± 2 vs. 6 ± 2 mmHg, P = 0.87; ICP, 15 ± 3 vs. 15 ± 4 mmHg, P = 0.68). Inflation of the thigh cuffs to 30 mmHg caused no meaningful reduction in CVP in all four individuals (5 ± 4 vs. 5 ± 4 mmHg; P = 0.1), coincident with minimal reduction in ICP (15 ± 3 vs. 14 ± 4 mmHg; P = 0.13). The application of inspiratory resistance breathing resulted in reductions in both ICP and CVP, likely due to intrathoracic unloading.NEW & NOTEWORTHY Spaceflight causes pathological changes in the eye that may be due to the absence of gravitational unloading of intracranial pressure (ICP) under microgravity conditions commonly referred to as spaceflight-associated neuro-ocular syndrome (SANS), whereby countermeasures aimed at lowering ICP are necessary. These data show that impedance threshold breathing acutely reduces ICP via a reduction in central venous pressure (CVP). Whereas, acute thigh cuff inflation, a popular known spaceflight-associated countermeasure, had little effect on ICP and CVP.

General versus sports-specific injury prevention programs in athletes: A systematic review on the effects on performance.

INTRODUCTION: Injury prevention programs (IPPs) are an inherent part of training in recreational and professional sports. Providing performance-enhancing benefits in addition to injury prevention may help adjust coaches and athletes' attitudes towards implementation of injury prevention into daily routine. Conventional thinking by players and coaches alike seems to suggest that IPPs need to be specific to one's sport to allow for performance enhancement. The systematic literature review aims to firstly determine the IPPs nature of exercises and whether they are specific to the sport or based on general conditioning. Secondly, can they demonstrate whether general, sports-specific or even mixed IPPs improve key performance indicators with the aim to better facilitate long-term implementation of these programs? METHODS: PubMed and Web of Science were electronically searched throughout March 2018. The inclusion criteria were randomized control trials, publication dates between Jan 2006 and Feb 2018, athletes (11-45 years), injury prevention programs and included predefined performance measures that could be categorized into balance, power, strength, speed/agility and endurance. The methodological quality of included articles was assessed with the Cochrane Collaboration assessment tools. RESULTS: Of 6619 initial findings, 22 studies met the inclusion criteria. In addition, reference lists unearthed a further 6 studies, making a total of 28. Nine studies used sports specific IPPs, eleven general and eight mixed prevention strategies. Overall, general programs ranged from 29-57% in their effectiveness across performance outcomes. Mixed IPPs improved in 80% balance outcomes but only 20-44% in others. Sports-specific programs led to larger scale improvements in balance (66%), power (83%), strength (75%), and speed/agility (62%). CONCLUSION: Sports-specific IPPs have the strongest influence on most performance indices based on the significant improvement versus control groups. Other factors such as intensity, technical execution and compliance should be accounted for in future investigations in addition to exercise modality.

High-intensity interval training in the therapy and aftercare of cancer patients: a systematic review with meta-analysis.

PURPOSE: This review and meta-analysis aimed to evaluate the effects of high-intensity interval training (HIIT) compared to usual care (UC) or moderate-intensity training (MIE) on physical fitness and health-related outcomes in cancer patients across all stages of therapy and aftercare. METHODS: Databases were systematically searched in accordance with the PRISMA guidelines until October 4th, 2018. Eligibility criteria included adult patients of various cancer types, performing HIIT vs. UC or MIE. Outcomes of interest included physical fitness (cardiorespiratory fitness [VO2peak] and functional capacity) and health-related outcomes (body composition, quality of life, cancer-related fatigue, and blood-borne biomarkers). Mean differences (MD) were calculated and pooled to generate effect sizes for VO2peak. RESULTS: The search identified 1453 studies, out of which 12 articles were included. The average duration of interventions was 6.7 ± 3.0 weeks, with 2.8 ± 0.5 sessions per week. The meta-analysis for VO2peak showed superiority of HIIT compared to UC (MD 3.73; 95% CI 2.07, 5.39; p < 0.001) but not MIE (MD 1.36; 95% CI - 1.62, 4.35; p = 0.370). Similarly, no superior effects of HIIT compared to MIE were found for quality of life or changes in lean mass, while evidence was provided for a larger reduction in fat mass. CONCLUSION: This systematic review showed that short-term HIIT induces similar positive effects on physical fitness and health-related outcomes as MIE but seems to be superior compared to UC. Thus, HIIT might be a time-efficient intervention for cancer patients across all stages of therapy and aftercare. IMPLICATIONS FOR CANCER SURVIVORS: High-intensity interval training (HIIT) is superior compared to usucal care in improving physical fitness and health-related outcomes in cancer patients across all stages of therapy and aftercare. Currently, there is no evidence for the benefits of HIIT compared to aerobic training of moderate intensity (MIE) for changes in cardiorespiratory fitness, lean mass and patient-reported outcomes. Reductions in fat mass may be more pronounced in HIIT compared to MIE when training is performed in aftercare.

General versus sports-specific injury prevention programs in athletes: A systematic review on the effect on injury rates.

INTRODUCTION: Annually, 2 million sports-related injuries are reported in Germany of which athletes contribute to a large proportion. Multiple sport injury prevention programs designed to decrease acute and overuse injuries in athletes have been proven effective. Yet, the programs' components, general or sports-specific, that led to these positive effects are uncertain. Despite not knowing about the superiority of sports-specific injury prevention programs, coaches and athletes alike prefer more specialized rather than generalized exercise programs. Therefore, this systematic review aimed to present the available evidence on how general and sports-specific prevention programs affect injury rates in athletes. METHODS: PubMed and Web of Science were electronically searched throughout April 2018. The inclusion criteria were publication dates Jan 2006-Dec 2017, athletes (11-45 years), exercise-based injury prevention programs and injury incidence. The methodological quality was assessed with the Cochrane Collaboration assessment tools. RESULTS: Of the initial 6619 findings, 15 studies met the inclusion criteria. In addition, 13 studies were added from reference lists and external sources making a total of 28 studies. Of which, one used sports-specific, seven general and 20 mixed prevention strategies. Twenty-four studies revealed reduced injury rates. Of the four ineffective programs, one was general and three mixed. CONCLUSION: The general and mixed programs positively affect injury rates. Sports-specific programs are uninvestigated and despite wide discussion regarding the definition, no consensus was reached. Defining such terminology and investigating the true effectiveness of such IPPs is a potential avenue for future research.

Accuracy of training recommendations based on a treadmill multistage incremental exercise test.

Competitive runners will occasionally undergo exercise in a laboratory setting to obtain predictive and prescriptive information regarding their performance. The present research aimed to assess whether the physiological demands of lab-based treadmill running (TM) can simulate that of over-ground (OG) running using a commonly used protocol. Fifteen healthy volunteers with a weekly mileage of ≥ 20 km over the past 6 months and treadmill experience participated in this cross-sectional study. Two stepwise incremental tests until volitional exhaustion was performed in a fixed order within one week in an Outpatient Clinic research laboratory and outdoor athletic track. Running velocity (IATspeed), heart rate (IATHR) and lactate concentration at the individual anaerobic threshold (IATbLa) were primary endpoints. Additionally, distance covered (DIST), maximal heart rate (HRmax), maximal blood lactate concentration (bLamax) and rate of perceived exertion (RPE) at IATspeed were analyzed. IATspeed, DIST and HRmax were not statistically significantly different between conditions, whereas bLamax and RPE at IATspeed showed statistical significance (p < 0.05). Apart from RPE at IATspeed, IATspeed, DIST, HRmax and bLamax strongly correlate between conditions (r = 0.815-0.988). High reliability between conditions provides strong evidence to suggest that running on a treadmill are physiologically comparable to that of OG and that training recommendations and be made with assurance.

Effect of high-intensity perturbations during core-specific sensorimotor exercises on trunk muscle activation.

Core-specific sensorimotor exercises are proven to enhance neuromuscular activity of the trunk. However, the influence of high-intensity perturbations on training efficiency is unclear within this context. Sixteen participants (29±2yrs; 175±8cm; 69±13kg) were prepared with a 12-lead bilateral trunk EMG. Warm-up on a dynamometer was followed by maximum voluntary isometric trunk (flex/ext) contraction (MVC). Next, participants performed four conditions for a one-legged stance with hip abduction on a stable surface (HA) repeated randomly on an unstable surface (HAP), on a stable surface with perturbation (HA+P), and on an unstable surface with perturbation (HAP+P). Afterwards, bird dog (BD) was performed under the same conditions (BD, BDP, BD+P, BDP+P). A foam pad under the foot (HA) or the knee (BD) was used as an unstable surface. Exercises were conducted on a moveable platform. Perturbations (ACC 50m/sec2;100ms duration;10rep.) were randomly applied in the anterior-posterior direction. The root mean square (RMS) normalized to MVC (%) was calculated (whole movement cycle). Muscles were grouped into ventral right and left (VR;VL), and dorsal right and left (DR;DL). Ventral-Dorsal and right-left ratios were calculated (two way repeated-measures ANOVA;α=0.05). Amplitudes of all muscle groups in bird dog were higher compared to hip abduction (p≤0.0001; Range: BD: 14±3% (BD;VR) to 53±4%; HA: 7±2% (HA;VR) to 16±4% (HA;DR)). EMG-RMS showed significant differences (p<0.001) between conditions and muscle groups per exercise. Interaction effects were only significant for HA (p=0.02). No significant differences were present in EMG ratios (p>0.05). Additional high-intensity perturbations during core-specific sensorimotor exercises lead to increased neuromuscular activity and therefore higher exercise intensities. However, the beneficial effects on trunk function remain unclear. Nevertheless, BD is more suitable to address trunk muscles.