Association between physical fitness and executive functions in cognitively healthy female older adults: a cross-sectional study.

Cardiovascular endurance and muscular fitness seem to impact specific cognitive components in older females. However, it remains uncertain whether these relate to executive functions or if these correlations are limited to specific physical fitness indicators. This study aimed to determine the association between specific physical fitness components and executive functions in community-dwelling older females. Thirty-five cognitively healthy community-dwelling older females (71.5 ± 5.7 years) underwent a series of physical fitness tests. These included the handgrip strength test (HGT), the 6-min walk test (6MWT), the 8-foot up-and-go test (8FUGT), and the chair stand test (CST). Participants also completed trail A and trail B of the cognitive trail making test. Results showed that trail B reaction time had a negative association with both HGT (r = - 0.502; p = 0.002) and 6MWT (r = - 0.543; p < 0.001). Together, the HGT and 6MWT results explained 39% of the variation in trail B reaction times: HGT accounted for 18% and 6MWT for 21%. Better scores on the 6MWT and HGT-but not on the 8FUGT and CST-correlated with enhanced executive function in cognitively healthy community-dwelling older females. The results of this study underscore the importance of specific physical assessments, like the 6MWT and HGT, as potential indicators of executive function, offering targeted strategies for maintaining cognitive health in aging females.

Human dopaminergic system in the exercise-cognition link.

While the dopaminergic system is important for cognitive processes, it is also sensitive to the influence of physical activity (PA). We summarize current evidence on whether PA-related changes in the human dopaminergic system are associated with alterations in cognitive performance, discuss recent advances, and highlight challenges and opportunities for future research.

Association between changes in habitual stepping activity and cognition in older adults.

Advancing age is associated with declines in cognitive function. Although physical activity is thought to protect against this decline, it is unclear how a short-term uptake in daily steps or a decline in day-to-day step variability may contribute to cognition among older adults. We tested associations between changes in step counts, day-to-day step variability and executive cognitive functions among older adults taking part in a physical activity intervention. Thirty-seven older adults (33 females; 71.4 ± 6.3 years) completed a 10-week personalized physical activity intervention. Participants wore a Fitbit to measure daily step counts throughout the study. They also completed a computerized Stroop task before and after the intervention. Average step counts and step count variability via average-real-variability (ARV) were determined. Compared to pre-intervention, step counts increased (p < 0.001) and step variability decreased post-intervention (p = 0.04). Models describing the changes in step counts and ARV over the 10-weeks were cubic (both, p < 0.04). Reaction times during the simple (p = 0.002) and switching (p = 0.04) conditions were faster post-intervention. Change in step variability was positively associated with the change in reaction time for the switching condition (ß = 0.029, p = 0.002). On average, a reduction in day-to-day step variability was associated with improvements in cognitive flexibility.

The effects of cold exposure (cold water immersion, whole- and partial- body cryostimulation) on cardiovascular and cardiac autonomic control responses in healthy individuals: A systematic review, meta-analysis and meta-regression.

BACKGROUND: Cryostimulation and cold-water immersion (CWI) have recently gained widespread attention due to their association with changes in cardiovascular and cardiac autonomic control responses. Therefore, the aim of the present systematic review and meta-analysis was to identify the global impact of such cold exposures on cardiovascular and cardiac autonomic activity. METHODS: Three databases (PubMed, Embase, Web-of-Science) were used. Studies were eligible for inclusion if they were conducted on healthy participants using cryostimulation and/or CWI. The outcomes included measurements of blood pressure (BP), heart rate (HR), and heart rate variability (HRV) indices: RR interval (RR), Root mean square of successive RR interval differences (RMSSD), low frequency band (LF), high frequency band (HF), and LF/HF ratio. RESULTS: Among the 27 articles included in our systematic literature review, only 24 were incorporated into the meta-analysis. Our results reveal a significant increase in HRV indices: RMSSD (Standardized mean difference (SMD) = 0.61, p < 0.001), RR (SMD = 0.77, p < 0.001), and HF (SMD = 0.46, p < 0.001), as well as significantly reduced LF (SMD = -0.41, p < 0.001) and LF/HF ratio (SMD = -0.25, p < 0.01), which persisted up to 15 min following cold exposure. Significantly decreased heart rate (SMD = -0.16, p < 0.05), accompanied by slightly increased mean BP (SMD = 0.28, p < 0.001), was also observed. These results seem to depend on individual characteristics and the cooling techniques. CONCLUSION: Our meta-analysis suggests that cryostimulation and/or CWI exposure enhance parasympathetic nervous activity. There is scarce scientific literature regarding the effect of individual characteristics on cold-induced physiological responses.

Arm cooling selectively impacts sensorimotor control.

The benefits of cold have long been recognized in sport and medicine. However, it also brings costs, which have more rarely been investigated, notably in terms of sensorimotor control. We hypothesized that, in addition to peripheral effects, cold slows down the processing of proprioceptive cues, which has an impact on both feedback and feedforward control. We therefore compared the performances of participants whose right arm had been immersed in either cold water (arm temperature: 14°C) or lukewarm water (arm temperature: 34°C). In experiment 1, we administered a Fitts's pointing task and performed a kinematic analysis to determine whether sensorimotor control processes were affected by the cold. Results revealed 1) modifications in late kinematic parameters, suggesting changes in the use of proprioceptive feedback, and 2) modifications in early kinematic parameters, suggesting changes in action representations and/or feedforward processes. To explore our hypothesis further, we ran a second experiment in which no physical movement was involved, and thus no peripheral effects. Participants were administrated a hand laterality task, known to involve implicit motor imagery and assess the internal representation of the hand. They were shown left- and right-hand images randomly displayed in different orientations in the picture plane and had to identify as quickly and as accurately as possible whether each image was of the left hand or the right hand. Results revealed slower responses and more errors when participants had to mentally rotate the cooled hand in the extreme orientation of 160°, further suggesting the impact of cold on action representations.NEW & NOTEWORTHY We investigated how arm cooling modulates sensorimotor representations and sensorimotor control. Arm cooling induced changes in early kinematic parameters of pointing, suggesting an impact on feedforward processes or hand representation. Arm cooling induced changes in late kinematic parameters of pointing, suggesting an impact on feedback processes. Arm cooling also affected performance on a hand laterality task, suggesting that action representations were modified.

Frailty is associated with worse executive function and higher cerebral blood velocity in cognitively healthy older adults: a cross-sectional study.

Frailty is characterized by an increased vulnerability to adverse health events. Executive function impairment is an early sign of progression towards cognitive impairments. Whether frailty is associated with executive function and the associated mechanisms are unclear. We test the hypothesis that higher frailty is associated with worse executive function (Trail Making Test) and if aerobic fitness, prefrontal cortex oxygenation (ΔO2Hb), or middle-cerebral artery velocity (MCAv) impact this association. Forty-one (38 females) cognitively health older adults (70.1 ± 6.3 years) completed a Trail task and 6-min walk test. Prefrontal cortex oxygenation was measured during the Trail task (via functional near-infrared spectroscopy) and MCAv in a sub-sample (n=26, via transcranial Doppler). A 35-item frailty index was used. Frailty was independently, non-linearly related to trail B performance (Frailty2: ß=1927 [95% CI: 321-3533], p = 0.02), with the model explaining 22% of the variance of trail B time (p = 0.02). Aerobic fitness was an independent predictor of trail B (ß=-0.05 [95% CI: -0.10-0.004], p = 0.04), but age and ΔO2Hb were not (both, p > 0.78). Frailty was positively associated with the difference between trails B and A (ß=105 [95% CI: 24-186], p = 0.01). Frailty was also associated with a higher peak MCAv (ρ = 0.40, p = 0.04), but lower ΔO2Hb-peakMCAv ratio (ρ = -0.44, p = 0.02). Higher frailty levels are associated to worse Trail times after controlling for age, aerobic fitness, and prefrontal oxygenation. High frailty level may disproportionately predispose older adults to challenges performing executive function tasks that may manifest early as a compensatory higher MCAv despite worse executive function, and indicate a greater risk of progressing to cognitive impairment.

Effects of combined physical and cognitive program performed in socially enriched environment on older people's cognitive abilities and quality of life (StimCoAPS): study protocol for a randomized controlled trial.

The number of older people worldwide is constantly increasing. However, ageing is accompanied by a decline in cognitive ability that can affect quality of life. Cognitive, physical and social activities can all slow this decline but social factors and their contribution to the well-being remain under-researched. The aim of this study is to analyse how the practice environment can foster these social relations and thus enhance well-being and to identify the psychological dimensions that are activated by social relations. This study is a 3-year randomised controlled trial designed to assess the effects on participants' cognitive abilities and quality of life of a combined (ie, physical and cognitive) training programme in different social practice environments. A total of 159 older people (≥65 years old) will be recruited and randomly assigned to one of three practice environments: individual practice at home (n=53), group practice in a gymnasium (n=53) and group practice in an enriched environment (n=53). All participants will complete 12-week combined training sessions and will be assessed four times: before the start, in the middle, at the end and 6 months after the end of the programme. They will undergo cognitive function (episodic memory and executive functions), physical capacity (aerobic fitness, muscle strength and dynamic balance) and psychosocial assessments (indicators of psychological well-being, social support, self-esteem, anxiety, depression and achievement goal strategies), as well as semistructured interviews. Statistical analyses will be conducted to assess the effect of the practice environment on the perceived benefits of this programme in terms of cognitive abilities and quality of life, and to determine the role of psychosocial factors in this relationship. This protocol has been approved by an institutional review board (CERSTAPS: IRB00012476-2022-20-01-146). Trials registration number: NCT05721508.

Partial-body cryostimulation does not impact peripheral microvascular responsiveness but reduces muscular metabolic O2 consumption (mV˙O2) at rest.

This study aimed to investigate the effect of partial-body cryostimulation (PBC) on microvascular responsiveness and muscular metabolic O2 consumption rate (mV˙O2). Twenty healthy young adults (ten males and ten females) underwent a post-occlusive reactive hyperemia (PORH) test at the flexor digitorum superficialis area before and after a 3-min PBC session and a 3-min control session. Using near-infrared spectroscopy, occlusion and reperfusion slopes were calculated: oxyhemoglobin ([HbO2]) decrease rate ([HbO2] slope 1), deoxyhaemoglobin ([HHb]) increase rate ([HHb] slope 1), [HbO2] increase rate ([HbO2] slope 2), and [HHb] increase rate ([HHb] slope 2. Using HbO2 kinetics during the occlusion, mV˙O2 was also calculated to characterize myocytes' metabolic O2 consumption. HbO2 slope 1 value was lower after PBC than before PBC (-0.15 ± 0.08 vs -0.24 ± 0.11 s-1; respectively; P < 0.05) in male participants only. A lower [HHb] slope 1 was also observed after PBC compared to before PBC (0.18 ± 0.10 vs 0.24 ± 0.16 s-1; P < 0.05) with no interaction for sex categories. mV˙O2 was significantly lower after PBC than before (pre values 14.75 ± 3.94 vs 18.47 ± 5.73 µMO2Hb.s-1; respectively; P < 0.01) with no interaction between sex categories. No changes in the calculated slope 2 were observed. These findings suggest that a single session of PBC reduces the muscular metabolic O2 needs at rest; however, it does not alter the vascular ability to provide O2 to the myocytes.

Acute Effects of a Maximal Cardiopulmonary Exercise Test on Cardiac Hemodynamic and Cerebrovascular Response and Their Relationship with Cognitive Performance in Individuals with Type 2 Diabetes.

Cardiovascular and cerebrovascular diseases are prevalent in individuals with type 2 diabetes (T2D). Among people with T2D aged over 70 years, up to 45% might have cognitive dysfunction. Cardiorespiratory fitness (V˙O2max) correlates with cognitive performances in healthy younger and older adults, and individuals with cardiovascular diseases (CVD). The relationship between cognitive performances, V˙O2max, cardiac output and cerebral oxygenation/perfusion responses during exercise has not been studied in patients with T2D. Studying cardiac hemodynamics and cerebrovascular responses during a maximal cardiopulmonary exercise test (CPET) and during the recovery phase, as well as studying their relationship with cognitive performances could be useful to detect patients at greater risk of future cognitive impairment. Purposes: (1) to compare cerebral oxygenation/perfusion during a CPET and during its post-exercise period (recovery); (2) to compare cognitive performances in patients with T2D to those in healthy controls; and (3) to examine if V˙O2max, maximal cardiac output and cerebral oxygenation/perfusion are associated with cognitive function in individuals with T2D and healthy controls. Nineteen patients with T2D (61.9 ± 7 years old) and 22 healthy controls (HC) (61.8 ± 10 years old) were evaluated on the following: a CPET test with impedance cardiography and cerebral oxygenation/perfusion using a near-infrared spectroscopy. Prior to the CPET, the cognitive performance assessment was performed, targeting: short-term and working memory, processing speed, executive functions, and long-term verbal memory. Patients with T2D had lower V˙O2max values compared to HC (34.5 ± 5.6 vs. 46.4 ± 7.6 mL/kg fat free mass/min; p < 0.001). Compared to HC, patients with T2D showed lower maximal cardiac index (6.27 ± 2.09 vs. 8.70 ± 1.09 L/min/m2, p < 0.05) and higher values of systemic vascular resistance index (826.21 ± 308.21 vs. 583.35 ± 90.36 Dyn·s/cm5·m2) and systolic blood pressure at maximal exercise (204.94 ± 26.21 vs. 183.61 ± 19.09 mmHg, p = 0.005). Cerebral HHb during the 1st and 2nd min of recovery was significantly higher in HC compared to T2D (p < 0.05). Executive functions performance (Z score) was significantly lower in patients with T2D compared to HC (-0.18 ± 0.7 vs. -0.40 ± 0.60, p = 0.016). Processing speed, working and verbal memory performances were similar in both groups. Brain tHb during exercise and recovery (-0.50, -0.68, p < 0.05), and O2Hb during recovery (-0.68, p < 0.05) only negatively correlated with executive functions performance in patients with T2D (lower tHb values associated with longer response times, indicating a lower performance). In addition to reduced V˙O2max, cardiac index and elevated vascular resistance, patients with T2D showed reduced cerebral hemoglobin (O2Hb and HHb) during early recovery (0-2 min) after the CPET, and lower performances in executive functions compared to healthy controls. Cerebrovascular responses to the CPET and during the recovery phase could be a biological marker of cognitive impairment in T2D.

Effect of simultaneous exercise and cognitive training on executive functions, baroreflex sensitivity, and pre-frontal cortex oxygenation in healthy older adults: a pilot study.

Aging is characterized by cognitive decline affecting daily functioning. To manage this socio-economic challenge, several non-pharmacological methods such as physical, cognitive, and combined training are proposed. Although there is an important interest in this subject, the literature is still heterogeneous. The superiority of simultaneous training compared to passive control and physical training alone seems clear but very few studies compared simultaneous training to cognitive training alone. The aim of this pilot study was to investigate the effect of simultaneous exercise and cognitive training on several cognitive domains in healthy older adults, in comparison with either training alone. Thirty-five healthy older adults were randomized into one of three experimental groups: exercise training, cognitive training, and simultaneous exercise and cognitive training. The protocol involved two 30-min sessions per week for 24 weeks. Cognitive performance in several domains, pre-frontal cortex oxygenation, and baroreflex sensitivity were assessed before and after the intervention. All groups improved executive performance, including flexibility or working memory. We found a group by time interaction for inhibition cost (F(2,28) = 6.44; p < 0.01) and baroreflex sensitivity during controlled breathing (F(2,25) = 4.22; p = 0.01), the magnitude of improvement of each variable being associated (r = -0.39; p = 0.03). We also found a decrease in left and right pre-frontal cortex oxygenation in all groups during the trail making test B. A simultaneous exercise and cognitive training are more efficient than either training alone to improve executive function and baroreflex sensitivity. The results of this study may have important clinical repercussions by allowing to optimize the interventions designed to maintain the physical and cognitive health of older adults.

Initiation of the Fixed Combination IDegLira in Patients with Type 2 Diabetes on Prior Injectable Therapy: Insights from the EASY French Real-World Study.

INTRODUCTION: Combining basal insulin (BI) with glucagon-like peptide-1 receptor agonist (GLP-1RA) is recognized as a relevant option to optimize glucose control in type 2 diabetes (T2D). The EASY real-world study aimed to evaluate the modalities of initiation and the effectiveness of the insulin Degludec plus Liraglutide (IDegLira) fixed-ratio combination in the French health care system. METHODS: A retrospective analysis included all patients with T2D and prior injectable therapy (GLP1-RA and/or insulin) who started treatment with IDegLira from September 2016 to December 2017 in 11 French diabetes centers. Baseline characteristics, reasons for IDegLira initiation, and modes of implementation were collected from the medical records. Changes in HbA1c and body weight were determined in patients with available follow-up data (nearest 6-month visit). RESULTS: IDegLira was initiated in 629 patients previously treated with GLP-1RA alone (11.6%), insulin alone (31.5% including 16.5% with BI and 14.9% with multiple daily injections [MDI]) or a free combination of GLP-1RA and insulin (56.9% including 44.8% with BI and 12.1% with MDI), associated or not with oral agents. IDegLira starting dose (mean of 29 ± 11 dose steps) most often exceeded the recommended dose, and was significantly correlated with prior BI but not GLP-1RA dosage. At initiation, mean age, body mass index (BMI) and HbA1c were 60.1 ± 10.2 years, 33.4 ± 6.2 kg/m2 and 8.8 ± 1.7%, respectively. In 461 patients with available follow-up (median 178 days), HbA1c decreased in all subgroups submitted to treatment intensification (- 1.7 ± 1.8% [p < 0.0001], - 1.2 ± 1.8% [p < 0.001] and - 0.8 ± 1.8% [p = 0.0026] in patients with prior GLP-1RA, BI or MDI therapy, respectively) but also in those switching from BI and GLP-1RA free combination (- 0.2 ± 0.9%, p = 0.0419). Significant body weight gain occurred in patients previously treated with GLP-1RA alone (+ 1.5 ± 5.8 kg, p = 0.0572) or combined to BI (+ 1.0 ± 3.1 kg, p < 0.0001) while those on BI (- 1.4 ± 4.6 kg, p = 0.0139) or MDI (- 1.4 ± 5.0 kg, p = 0.0484) experienced weight loss. CONCLUSIONS: While providing new information on the use of IDegLira in the French healthcare system, these data confirm the effectiveness of this fixed-ratio combination in the management of T2D.

Semaglutide for treatment of obesity in hemodialysis patients waiting for a kidney transplant: new hope?

Obesity limits the access to kidney transplantation and increases the risk of complications and mortality posttransplantation. Usual noninvasive measures, including lifestyle changes and dietary education, do not provide long-term and consistent body weight reduction. In many cases, only bariatric surgery allows patients to significantly reduce body weight. We here report two cases of obese hemodialysis (HD) patients who were successfully treated with off-labeled semaglutide, a glucagon-like peptide receptor agonist (GLP-1RA). The first patient had a body mass index (BMI) of 45.7 kg/m2 despite a history of partial gastrectomy. The second patient had a history of type 2 diabetes mellitus and a BMI of 36.5 kg/m2. Both patients started semaglutide at the maximal subcutaneous dose of 1 mg/week, which was clinically well tolerated. During the 9-month follow-up, body weight loss ranged from 6.5 to 9.0 kg, ∼1 kg/month. GLP-1RAs, such as semaglutide or liraglutide, could be a novel pharmacological alternative to bariatric surgeries for these HD patients.

Acute Effect of a Simultaneous Exercise and Cognitive Task on Executive Functions and Prefrontal Cortex Oxygenation in Healthy Older Adults.

The rapid increase in population aging and associated age-related cognitive decline requires identifying innovative and effective methods to prevent it. To manage this socio-economic challenge, physical, cognitive, and combined stimulations are proposed. The superiority of simultaneous training compared to passive control and physical training alone seems to be an efficient method, but very few studies assess the acute effect on executive function. This study aimed to investigate the acute effect of simultaneous physical and cognitive exercise on executive functions in healthy older adults, in comparison with either training alone. Seventeen healthy older adults performed three experimental conditions in randomized order: physical exercise, cognitive exercise, and simultaneous physical and cognitive exercise. The protocol involved a 30 min exercise duration at 60% of theoretical maximal heart rate or 30 min of cognitive exercise or both. Executive functions measured by the Stroop task and pre-frontal cortex oxygenation were assessed before and after the intervention. We found a main effect of time on executive function and all experimental condition seems to improve inhibition and flexibility scores (<0.05). We also found a decrease in cerebral oxygenation (Δ[HbO2]) in both hemispheres after each intervention in all cognitive performance assessed (p < 0.05). Simultaneous physical and cognitive exercise is as effective a method as either physical or cognitive exercise alone for improving executive function. The results of this study may have important clinical repercussions by allowing to optimize the interventions designed to maintain the cognitive health of older adults since simultaneous provide a time-efficient strategy to improve cognitive performance in older adults.

Effects of Cardiorespiratory Fitness on Cerebral Oxygenation in Healthy Adults: A Systematic Review.

Introduction: Exercise is known to improve cognitive functioning and the cardiorespiratory hypothesis suggests that this is due to the relationship between cardiorespiratory fitness (CRF) level and cerebral oxygenation. The purpose of this systematic review is to consolidate findings from functional near-infrared spectroscopy (fNIRS) studies that examined the effect of CRF level on cerebral oxygenation during exercise and cognitive tasks. Methods: Medline, Embase, SPORTDiscus, and Web of Science were systematically searched. Studies categorizing CRF level using direct or estimated measures of V̇O2max and studies measuring cerebral oxygenation using oxyhemoglobin ([HbO2]) and deoxyhemoglobin ([HHb]) were included. Healthy young, middle-aged, and older adults were included whereas patient populations and people with neurological disorders were excluded. Results: Following PRISMA guidelines, 14 studies were retained following abstract and full-text screening. Cycle ergometer or treadmill tests were used as direct measures of CRF, and one study provided an estimated value using a questionnaire. Seven studies examined the effects of CRF on cerebral oxygenation during exercise and the remaining seven evaluated it during cognitive tasks. Increased [HbO2] in the prefrontal cortex (PFC) was observed during cognitive tasks in higher compared to lower fit individuals. Only one study demonstrated increased [HHb] in the higher fit group. Exercise at submaximal intensities revealed increased [HbO2] in the PFC in higher compared to lower fit groups. Greater PFC [HHb] was also observed in long- vs. short-term trained males but not in females. Primary motor cortex (M1) activation did not differ between groups during a static handgrip test but [HHb] increased beyond maximal intensity in a lower compared to higher fit group. Conclusion: Consistent with the cardiorespiratory hypothesis, higher fit young, middle-aged, and older adults demonstrated increased cerebral oxygenation compared to lower fit groups. Future research should implement randomized controlled trials to evaluate the effectiveness of interventions that improve CRF and cerebral oxygenation longitudinally.

Cryostimulation for Post-exercise Recovery in Athletes: A Consensus and Position Paper.

Recovery after exercise is a crucial key in preventing muscle injuries and in speeding up the processes to return to homeostasis level. There are several ways of developing a recovery strategy with the use of different kinds of traditional and up-to-date techniques. The use of cold has traditionally been used after physical exercise for recovery purposes. In recent years, the use of whole-body cryotherapy/cryostimulation (WBC; an extreme cold stimulation lasting 1-4 min and given in a cold room at a temperature comprised from -60 to -195°C) has been tremendously increased for such purposes. However, there are controversies about the benefits that the use of this technique may provide. Therefore, the main objectives of this paper are to describe what is whole body cryotherapy/cryostimulation, review and debate the benefits that its use may provide, present practical considerations and applications, and emphasize the need of customization depending on the context, the purpose, and the subject's characteristics. This review is written by international experts from the working group on WBC from the International Institute of Refrigeration.

Cardiorespiratory fitness and prefrontal cortex oxygenation during Stroop task in older males.

AIM: The aim of the current study was to assess whether executive function and prefrontal oxygenation are dependent on fitness level and age in older adults. METHODS: Twenty-four healthy males aged between 55 and 69 years old were recruited for this study. They were stratified by age, leading to the creation of two groups: 55-60 years old and 61-69 years old. A median split based on CRF created higher- and lower-fit categories of participants. Cerebral oxygenation was assessed using functional near-infrared spectroscopy (fNIRS) during a computerized Stroop task. Accuracy (% of correct responses) and reaction times (ms) were used as behavioural indicators of cognitive performances. Changes in oxygenated (∆[HbO2]) and deoxygenated (∆[HHb]) hemoglobin were measured to capture neural changes. Repeated measures ANOVAs (CRF × Age × Stroop conditions) were performed to test the null hypothesis of an absence of interaction between CRF, Age and executive performance. RESULTS: We also found an interaction between CRF and age on reaction times (p = .001), in which higher fitness levels were related to faster reaction times in the 61-69 year olds but not in the 55-60 year olds. Regarding ΔHHb, the ANOVA revealed a main effect of CRF in the right PFC (p = .04), in which higher-fit participants had a greater Δ[HHb] than the lower-fit (d = 1.5). We also found fitness by age interaction for Δ[HHb] in the right PFC (p = .04). CONCLUSION: Our results support the positive association of CRF on cerebral oxygenation and Stroop performance in healthy older males. They indicated that high-fit individuals performed better in the 61-69 year olds group, but not in the 55-60 years old group. We also observed a greater PFC oxygenation change (as measured by Δ[HHb]) in the high-fit individuals.

Does branched-chain amino acid supplementation improve pulmonary rehabilitation effect in COPD?

BACKGROUND: Muscle wasting is frequent in chronic obstructive lung disease (COPD) and associated with low branched-chain amino acids (BCAA). We hypothesized that BCAA supplementation could potentiate the effect of a pulmonary rehabilitation program (PRP) by inducing muscular change. MATERIALS AND METHODS: Sixty COPD patients (GOLD 2-3) were involved in an ambulatory 4-week PRP either with BCAA oral daily supplementation or placebo daily supplementation in a randomized double-blind design. Maximal exercise test including quadriceps oxygenation measurements, functional exercise test, muscle strength, lung function tests, body composition, dyspnea and quality of life were assessed before and after PRP. RESULTS: Fifty-four patients (64.9 ± 8.3 years) completed the protocol. In both groups, maximal exercise capacity, functional and muscle performances, quality of life and dyspnea were improved after 4-week PRP (p ≤ 0.01). Changes in muscle oxygenation during the maximal exercise and recovery period were not modified after 4-week PRP in BCAA group. Contrarily, in the placebo group the muscle oxygenation kinetic of recovery was slowed down after PRP. CONCLUSION: This study demonstrated that a 4-week PRP with BCAA supplementation is not more beneficial than PRP alone for patients. A longer duration of supplementation or a more precise targeting of patients would need to be investigated to validate an effect on muscle recovery and to demonstrate other beneficial effects.

Impact of acute partial-body cryostimulation on cognitive performance, cerebral oxygenation, and cardiac autonomic activity.

We assessed the effects of a 3-min partial-body cryostimulation (PBC) exposure-where the whole body is exposed to extreme cold, except the head-on cognitive inhibition performance and the possible implications of parasympathetic cardiac control and cerebral oxygenation. In a randomized controlled counterbalanced cross-over design, eighteen healthy young adults (nine males and nine females) completed a cognitive Stroop task before and after one single session of PBC (3-min exposure at - 150 °C cold air) and a control condition (3 min at room temperature, 20 °C). During the cognitive task, heart rate variability (HRV) and cerebral oxygenation of the prefrontal cortex were measured using heart rate monitoring and near-infrared spectroscopy methods. We also recorded the cerebral oxygenation during the PBC session. Stroop performance after PBC exposure was enhanced (562.0 ± 40.2 ms) compared to pre-PBC (602.0 ± 56.4 ms; P < 0.042) in males only, accompanied by an increase (P < 0.05) in HRV indices of parasympathetic tone, in greater proportion in males compared to females. During PBC, cerebral oxygenation decreased in a similar proportion in males and females but the cerebral extraction (deoxyhemoglobin: ΔHHb) remained higher after exposure in males, only. These data demonstrate that a single PBC session enhances the cognitive inhibition performance on a Stroop task in males, partly mediated by a greater parasympathetic cardiac control and greater cerebral oxygenation. The effects of PBC on cognitive function seem different in females, possibly explained by a different sensitivity to cold stimulation.