Exercise and Implicit Memory: A Brief Systematic Review

2017 ◽  
Vol 121 (6) ◽  
pp. 1072-1085 ◽  
Author(s):  
Paul D. Loprinzi ◽  
Meghan K. Edwards

Background Emerging work demonstrates that acute exercise may enhance explicit memory function. No published systematic reviews have evaluated the totality of research examining the effects of exercise on implicit memory function, which was the purpose of this systematic review. Methods Databases (PubMed, PsychInfo, and Sports Discus) were searched to evaluate animal and human experimental studies evaluating the effects of exercise on implicit memory function. Results Among the 10 evaluated studies that met inclusionary criteria for this systematic review, 7 were conducted in animal models (rats or mice), with 3 utilizing human samples. Among the seven animal model studies, all employed a fear conditioning paradigm to evaluate implicit memory performance. All six animal studies employing a chronic exercise paradigm demonstrated evidence for associations between chronic exercise and enhanced fear conditioning. The one animal study evaluating a high-intensity acute bout of exercise showed that high-intensity acute exercise worsened implicit memory retrieval. Among the three human studies, one demonstrated a beneficial effect of acute exercise on implicit memory function. Discussion There is consistent evidence in animal models that chronic exercise enhances implicit memory, as assessed by fear conditioning. However, there have been too few human studies investigating this topic to render any meaningful conclusions regarding the relationship between exercise and cognitive-based implicit memory among humans.

2017 ◽  
Vol 32 (3) ◽  
pp. 691-704 ◽  
Author(s):  
Paul D. Loprinzi ◽  
Emily Frith ◽  
Meghan K. Edwards ◽  
Eveleen Sng ◽  
Nicole Ashpole

Objective: To systematically summarize the experimental effects of exercise on cognitive-related memory function among young to middle-aged adults, which has yet to be done in the literature. Data Source: PubMed. Study Inclusion and Exclusion Criteria: Studies were included if they were published in the English language, indexed in PubMed, employed an experimental study design (eg, traditional parallel group randomized controlled trial: either acute intervention or chronic/training intervention study), and conducted among human adults. Studies were excluded if nonhumans (ie, animal models) were studied, if children/adolescents (<18 years) or older adults (>50 years) were evaluated, and if select chronic diseases (eg, diabetes and dementia) were present. Data Extraction: A systematic review approach was employed. Data Synthesis: An extraction table was created synthesizing the key results, and recommendations for future research are emphasized. Results: Among the 17 evaluated studies, 2 were published before the year 2000 (ie, 1998 and 1999), 2 were published in 2007, and the remaining 13 were published in the years 2011 and beyond. This highlights the emergence of this research topic within this age-group (young to middle-aged adults). Among the 17 evaluated studies, 14 were conducted among healthy samples, with 3 conducted among those with a diagnosis of depression. Among the 17 studies, 4 employed a chronic training protocol, with 13 utilizing an acute exercise protocol. Among the 3 experimental studies in the depressed population, all demonstrated a favorable effect of exercise on memory function. Among the 14 trials in the nondepressed population, 10 (71%) demonstrated a favorable effect of exercise on some aspect of memory function. Conclusion: Acute and chronic exercise appears to play a pronounced effect on memory function among young to middle-aged adults. Implications and recommendations for future research are outlined in this systematic review.


2018 ◽  
Vol 52 (21) ◽  
pp. 1357-1366 ◽  
Author(s):  
Margie H Davenport ◽  
Frances Sobierajski ◽  
Michelle F Mottola ◽  
Rachel J Skow ◽  
Victoria L Meah ◽  
...  

ObjectiveTo perform a systematic review and meta-analysis to explore the relationship between prenatal exercise and glycaemic control.DesignSystematic review with random-effects meta-analysis and meta-regression.Data sourcesOnline databases were searched up to 6 January 2017.Study eligibility criteriaStudies of all designs were included (except case studies and reviews) if they were published in English, Spanish or French, and contained information on the population (pregnant women without contraindication to exercise), intervention (subjective or objective measures of frequency, intensity, duration, volume or type of acute or chronic exercise, alone (‘exercise-only’) or in combination with other intervention components (eg, dietary; ‘exercise+cointervention’) at any stage of pregnancy), comparator (no exercise or different frequency, intensity, duration, volume and type of exercise) and outcome (glycaemic control).ResultsA total of 58 studies (n=8699) were included. There was ‘very low’ quality evidence showing that an acute bout of exercise was associated with a decrease in maternal blood glucose from before to during exercise (6 studies, n=123; mean difference (MD) −0.94 mmol/L, 95% CI −1.18 to −0.70, I2=41%) and following exercise (n=333; MD −0.57 mmol/L, 95% CI −0.72 to −0.41, I2=72%). Subgroup analysis showed that there were larger decreases in blood glucose following acute exercise in women with diabetes (n=26; MD −1.42, 95% CI −1.69 to −1.16, I2=8%) compared with those without diabetes (n=285; MD −0.46, 95% CI −0.60 to −0.32, I2=62%). Finally, chronic exercise-only interventions reduced fasting blood glucose compared with no exercise postintervention in women with diabetes (2 studies, n=70; MD −2.76, 95% CI −3.18 to −2.34, I2=52%; ‘low’ quality of evidence), but not in those without diabetes (9 studies, n=2174; MD −0.05, 95% CI −0.16 to 0.05, I2=79%).ConclusionAcute and chronic prenatal exercise reduced maternal circulating blood glucose concentrations, with a larger effect in women with diabetes.


2018 ◽  
Vol 105 (4) ◽  
pp. 285-297 ◽  
Author(s):  
PD Loprinzi ◽  
P Ponce ◽  
E Frith

Emerging research demonstrates that exercise is favorably associated with several cognitive outcomes, including episodic memory function. The majority of the mechanistic work describing the underlying mechanisms of this effect has focused on chronic exercise engagement. Such mechanisms include, e.g., chronic exercise-induced neurogenesis, gliogenesis, angiogenesis, cerebral circulation, and growth factor production. Less research has examined the mechanisms through which acute (vs. chronic) exercise subserves episodic memory function. The purpose of this review is to discuss these potential underlying mechanisms, which include, e.g., acute exercise-induced (via several pathways, such as vagus nerve and muscle spindle stimulation) alterations in neurotransmitters, synaptic tagging/capturing, associativity, and psychological attention.


2019 ◽  
Vol 8 (1) ◽  
Author(s):  
Denise Grotto ◽  
Isabella Ferreira Camargo ◽  
Katia Kodaira ◽  
Lauren Giustti Mazzei ◽  
Juliana Castro ◽  
...  

Abstract Background Obesity and its consequences are worldwide epidemic problem; therefore, studies with strategies and mechanisms that favor weight loss to improve outcomes in health are necessary. Effects of mushrooms on body weight are uncertain. The aim of this systematic review is to determine the efficacy of mushrooms in weight loss in animal preclinical models. Method This is a systematic review of preclinical studies of animal models of obesity (any type of non-aquatic mammal), which were exposed to edible and medicinal mushrooms orally in comparison with the control. The following databases will be used: MEDLINE (PubMed), Web of Science, BIOSIS, SCOPUS, and gray literature. There will be no restriction of language, date, or publication status. The primary outcome will be body weight loss. And the secondary outcomes include the total amount of food consumed by the animals, analysis of metabolic parameters, inflammatory mediators, mortality for any causes, and any adverse effect reported. A team of reviewers will select, in pairs and independently, the titles and abstracts, extract data from qualifying studies, and assess bias risk (using SYstematic Review Centre for Laboratory animal Experimentation SYRCLE’s risk of bias tool and the Collaborative Approach to Meta-Analysis and Review of Animal Data from Experimental Studies (CAMARADES) checklist). The standardized mean difference (SMD) will be calculated to measure treatment effect, with 95% confidence intervals (95% CI). The heterogeneity between-study will be calculated by I2 inconsistency values and Cochran’s Q statistical test, where I2 > 50% and/or p < 0.10 suggest high heterogeneity meta-analyses of random effects will be conducted as possible. Discussion Although many experimental studies about the effects of mushrooms on obesity have already been published, there is still no consensus in the literature. This study will provide evidences of preclinical research on mushrooms and their relation to body weight loss in animal models of obesity, being non-aquatic mammals. Also, this systematic review will show the limitations and strengths of the studies available in the literature, as well as it will to encourage the financing of new studies by public health managers and governmental entities. Systematic review registration PROSPERO (CRD42019125299).


2014 ◽  
Vol 100 ◽  
pp. 1-12 ◽  
Author(s):  
Tomer Shechner ◽  
Melanie Hong ◽  
Jennifer C. Britton ◽  
Daniel S. Pine ◽  
Nathan A. Fox

2021 ◽  
Vol 17 (1) ◽  
pp. 85-103
Author(s):  
Paul D. Loprinzi ◽  
Sierra Day ◽  
Rebecca Hendry ◽  
Sara Hoffman ◽  
Alexis Love ◽  
...  

The specific questions addressed from this research include: (1) Does high-intensity acute exercise improve memory?, (2) If so, do the mechanisms occur via encoding, consolidation, or retrieval? and (3) If acute exercise occurs in multiple phases of memory (e.g., before encoding and during consolidation), does this have an additive effect on memory? Three experimental, within-subject, counterbalanced studies were conducted among young adults. High-intensity exercise involved a 20-minutes bout of exercise at 75% of heart rate reserve. Memory was evaluated from a word-list task, including multiple evaluations out to 24-hours post-encoding. The timing of the exercise and memory assessments were carefully positioned to evaluate whether any improvements in memory were driven by mechanisms related to encoding, consolidation, and/or retrieval. We demonstrated that high-intensity acute exercise enhanced memory. This effect was robust (repeatable) and occurred through encoding, consolidation and retrieval-based mechanisms. Further, incorporating acute exercise into multiple phases of memory additively enhanced memory function.


2021 ◽  
Author(s):  
ling wang ◽  
yang yu ◽  
cong zhou ◽  
run wan ◽  
Yumin Li

Abstract Background and objectives: Cancer morbidity and mortality rates remain high, and thus, at present, considerable efforts are focused on finding drugs with higher sensitivity against tumor cells and fewer side effects. Several preclinical and clinical studies have examined the potential of repurposing disulfiram (DSF) as an anticancer treatment. This systematic review aimed to assess evidence regarding the antineoplastic activity of DSF in in vitro and in vivo models, as well as in humans.Methods: Two authors independently conducted this systematic review of English and Chinese articles from the PubMed, Embase, and the Cochrane Library databases up to July 2019. Eligible in vitro studies needed to include assessments of the apoptosis rate by flow cytometry using annexin V/propidium iodide, and studies in animal models and clinical trials needed to examine tumor inhibition rates, and progression-free survival (PFS) and overall survival (OS), respectively. Data were analyzed using descriptive statistics.Results: Overall, 35 studies, i.e., 21 performed in vitro, 11 based on animal models, and three clinical trials, were finally included. In vitro and animal studies indicated that DSF was associated with enhanced apoptosis and tumor inhibition rates. Human studies showed that DSF prolongs PFS and OS. The greatest anti-tumor activity was observed when DSF was used as combination therapy or as a nanoparticle-encapsulated molecule.Conclusions: This systematic review provides evidence regarding the anti-tumor activity of DSF in vitro, in animals, and in humans and indicates the optimal forms of treatment to be evaluated in future research.


2019 ◽  
Vol 15 (4) ◽  
pp. 700-716
Author(s):  
Paul D. Loprinzi ◽  
Morgan Gilbert ◽  
Gina Robinson ◽  
Briahna Dickerson

Emerging work suggests that acute exercise can enhance explicit memory function. Minimal research, however, has examined whether acute exercise is associated with implicit memory, which was the purpose of this study. Three separate experimental studies were computed (N = 120; Mean age = 21). In Experiment 1, participants were randomly assigned to either a moderate-intensity bout of acute exercise (15-minute) or engaged in a seated control task (15-minute), followed by the completion of a word-fragmentation implicit memory task. Experiment 2 replicated Experiment 1, but instead employed a higher-intensity exercise protocol. For Experiment 3, participants were randomly assigned to either a moderate-intensity bout of acute exercise (15-minute) or engaged in a seated control task (15-minute), followed by the completion of a real world, 3-dimensional implicit memory task. For Experiment 1, the exercise and control groups, respectively, had an implicit memory score of 7.0 (0.5) and 7.5 (0.6) (t(38) = 0.67, p = .51). For Experiment 2, the exercise and control groups, respectively, had an implicit memory score of 6.9 (1.9) and 7.8 (2.4) (t(38) = 1.27, p = .21). These findings suggest that exercise, and the intensity of exercise, does not alter implicit memory from a word fragmentation task. For Experiment 3, the exercise and control groups, respectively, had a discrimination implicit memory index score of 0.48 (0.18) and 0.29 (0.32) (t(38) = 2.16, p = .03). In conclusion, acute exercise does not influence a commonly used laboratory-based assessment of implicit memory but may enhance real world-related implicit memory function.


2020 ◽  
pp. 003151252097967
Author(s):  
Paul D. Loprinzi ◽  
Ashley Lovorn ◽  
Jackson Gilmore

The present experiment evaluated the effects of self-reported exercise behavior and an acute bout of high-intensity exercise on explicit memory function. The memory tasks were encoded either incidentally or intentionally; for intentional encoding, participants were told to focus on memorizing the stimuli (words), whereas for incidental encoding, participants were unaware that they would be subsequently asked to complete an object recognition task. Among a sample of 150 adults (Mage = 20 years), randomly assigned experimental participants engaged in the following task sequence: (a) incidentally encoded a series of objects, (b) engaged in 20 minutes of high-intensity exercise, (c) intentionally encoded a word list, and (d) completed explicit memory retrieval tasks. Control group participants viewed a time matched video in lieu of high intensity exercise. We measured self-reported exercise behavior via an exercise questionnaire. We did not observe convincing evidence of an effect of high-intensity acute exercise, when occurring during the early consolidation period, on memory function, for either incidental or intentional encoding tasks. However, self-reported engagement in moderate-to-vigorous physical activity was favorably associated with explicit memory performance.


2020 ◽  
Vol 11 (8) ◽  
pp. 6807-6817
Author(s):  
Alex Cheok ◽  
Trevor W. George ◽  
Ana Rodriguez-Mateos ◽  
Paul W. Caton

This systematic review assesses the evidence for the effects of edible cacti (dragon fruit and cactus pear) on vascular and endothelial function based on animal models and human studies.


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