Effects of Exercise on Explicit Memory Function: Incidental and Intentional Encoding May Depend on Exercise Timing

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.

2021 ◽  

Purpose: In this study, proton nuclear magnetic resonance (1H NMR) spectroscopy was used to evaluate the effect of astaxanthin (ASTA) supplementation on changes in human plasma elicited by high-intensity exercise. Methods: Sixteen adult males were randomly divided into 2 groups (n = 8 per group), namely the control group C (placebo for 28 d, 4 weeks) and experimental group M (supplement medium dose ASTA: 12 mg/d for 28 d, 4 weeks). At 08:00 on the 29th day, fasting blood sampling was carried out on all the participants, and the samples were tested in the laboratory for the first time. Later, the participants performed acute exercise on a pedal-powered bicycle with full strength for 30 s × 3/3 min intervals (loading a weight of 0.075 kg/kg). Blood sampling was then respectively performed immediately, 1 h after the acute exercise, and 1 d after the acute exercise. Results: (1) The metabolites of the subjects of the two groups were found to be diverse at different time points, and 34 types of metabolites were screened from the two groups. (2) The metabolites with differences between the two groups 1 h after exercise were β-hydroxybutyrate, creatine, and glycerol. The levels of β-hydroxybutyric acid and glycerol in group M were significantly lower than those in group C, while the level of creatine was significantly higher. Compared with the resting state 1 h after exercise, the metabolites in common between the two groups were leucine (Leu), valine (Val), and citric acid (CA), and their levels were significantly decreased. (3) During the period between 1 h and 1 d after exercise, the different metabolites between the two groups were methionine (Met) and glycerol. The glycerol levels of group M were significantly lower than those of group C, while the levels of Met were significantly higher. The co-metabolites of the subjects in groups C and M 1 d after exercise were creatine, glucose, and glycerol, the levels of which were all significantly increased. Conclusions: (1) One hour after exercise, the consumption of creatine, amino acids, fatty acids, and CA was found to be obvious, and ASTA intake was conducive to their recovery. (2) After high-intensity exercise, changes occurred in the body's energy metabolism that involved the metabolism of glucose, lipids, and proteins, and basic recovery was found 1 d after exercise. The findings of this study suggest that ASTA intake can accelerate metabolic recovery induced by physical exercise.


2019 ◽  
Vol 9 (2) ◽  
pp. 143-149 ◽  
Author(s):  
Emma K. Dilley ◽  
Liye Zou ◽  
Paul D. Loprinzi

Background: Previous experimental work demonstrates that acute exercise may enhance episodic memory performance. However, limited research has examined the extent to which acute exercise influences false episodic memory production, and no studies, to date, have examined whether there is an intensity-specific effect of acute exercise on both true episodic and false episodic memories. Thus, the present experiment evaluated the effects of intensity-specific acute exercise on episodic memory and false episodic memory. Methods: A three-arm, parallel, between-group randomized controlled trial was employed in the University setting, with participants (N=60; Mage= 20.8 years) randomized into a moderate intensity exercise group (15-minute bout of treadmill exercise at 50% heart rate reserve), a high intensity exercise group (15-minute bout of treadmill exercise at 80% heart rate reserve), or a control group (time-matched period of sitting). True episodic and false episodic memory were both assessed using 6 word-lists from the Deese-Roediger-McDermott (DRM) paradigm, including both a short-term recall and a delayed memory recognition assessment. Results: For the number of words recalled across each of the 6 lists, there was a significant main effect for list (P<0.001, η2p=0.15), marginally significant main effect for group (P=0.07, η2p=0.09), but no list by group interaction effect (P=0.44, η2p=0.03). Those in the high-intensity exercise group recalled significantly (P<0.05) more words than the control group. For the false episodic word recall, across various lists, high-intensity acute exercise was associated with a greater rate of false episodic memories. For the memory recognition task, there was no main effect for word type (P=0.46, η2p=0.01), group (P=0.4443, η2p=.03), word type by group interaction (P=0.44,η2p=0.03), recall by group interaction (P=0.4441, η2p=0.04), or word type by recall by group interaction (P=0.32, η2p=0.04). However, there was a main effect for recall (P<0.001, η2p=.54)and a word type by recall interaction (P<0.001, η2p=0.77).Conclusion: These findings suggest that acute high-intensity exercise may enhance true episodic memories, and, possibly, also increase the rate of false episodic memories. We discuss these findings in the context of how different acute exercise intensities may have unique and differential effects on underlying mechanistic processes related to true and false episodic memory.


2019 ◽  
Vol 8 (8) ◽  
pp. 1200
Author(s):  
Paul D. Loprinzi ◽  
Ashley Lovorn ◽  
Emma Hamilton ◽  
Noelle Mincarelli

Background and Objective: Once a memory is reactivated, it enters a labile state and, thus, is vulnerable to memory decay and/or distortion. Recent research demonstrates that acute, high-intensity exercise is associated with enhanced episodic memory function. Very limited research, however, has evaluated whether acute exercise can attenuate memory distortion from memory reactivation, which was the purpose of this study. Methods: A between-subject randomized controlled intervention was employed. Participants (N = 80) were randomly assigned to one of four groups, including (1) reminder with exercise, (2) reminder, (3) no reminder, and (4) interference control. For the groups, participants completed three visits (Visit 1, 2, and 3), which all occurred 48 hours apart. An exception to this was the interference control group, which did not complete Visit 2. On Visit 2, the reminder with exercise group engaged in a 15 min bout of high-intensity exercise (80% of heart rate reserve) immediately after memory reactivation. On Visit 3, participants engaged in a free recall (4 trials) of the memory task encoded on Visit 1. Results: In a 4 (groups) × 4 (learning trials) mixed-measures ANOVA, with the group as the between-subjects variable and the learning trials (1–4) as the within-subject variable, there was a significant main effect group, F(3, 76) = 4.18, p = 0.008, η2p = 0.14, and a significant main effect for the learning trials, F(2.40, 182.59) = 49.25, p < 0.001, η2p = 0.39, but there was no group by learning trials interaction, F(7.20, 182.59) = 1.07, p = 0.38, η2p = 0.04. Conclusion: Our findings suggest that exercise may, potentially, attenuate memory distortion from memory reactivation. However, future work is needed to confirm these findings before any strong conclusions can be reached.


2019 ◽  
Author(s):  
Xin Li ◽  
Charalambos C. Charalambous ◽  
Darcy S. Reisman ◽  
Susanne M. Morton

AbstractBackgroundAcute exercise can increase motor cortical excitability and enhance motor learning in healthy individuals, an effect known as exercise priming. Whether it has the same effects in people with stroke is unclear.ObjectivesThe objective of this study was to investigate whether a short, clinically-feasible high-intensity exercise protocol can increase motor cortical excitability in non-exercised muscles of chronic stroke survivors.MethodsThirteen participants with chronic, unilateral stroke participated in two sessions, at least one week apart, in a crossover design. In each session, they underwent either high-intensity lower extremity exercise or quiet rest. Motor cortical excitability of the extensor carpi radialis muscles was measured bilaterally with transcranial magnetic stimulation before and immediately after either exercise or rest. Motor cortical excitability changes (post-exercise or rest measures normalized to pre-test measures) were compared between exercise vs. rest conditions.ResultsAll participants were able to reach the target high-intensity exercise level. Blood lactate levels increased significantly after exercise (p < 0.001, d = 2.85). Resting motor evoked potentials from the lesioned hemisphere increased after exercise compared to the rest condition (p = 0.046, d = 2.76), but this was not the case for the non-lesioned hemisphere (p = 0.406, d = 0.25).ConclusionsHigh-intensity exercise can increase lesioned hemisphere motor cortical excitability in a non-exercised muscle post-stroke. Our short and clinically-feasible exercise protocol shows promise as a potential priming method in stroke rehabilitation.


2021 ◽  
Author(s):  
Xuchang Zhou ◽  
Hong Cao ◽  
Miao Wang ◽  
Jun Zou ◽  
wei wu

Abstract Background The purpose of this study was to explore whether moderate-intensity exercise can alleviate motion-induced post-traumatic osteoarthritis (PTOA) and the expression change of lncRNA H19 during this progression.Methods Twenty-week-old male C57BL/6 mice were randomly divided into five groups: model control group (CM group, n = 6), treadmill model group (M group, n = 6), rehabilitation control group (CK group, n = 6), treadmill model + rehabilitation training group (K group, n = 6) and treadmill model + rest group (J group, n = 6). Paraffin sections were used to observe the pathological changes in the mouse knee joint in each group. A micro-CT was used to scan the knee joint to obtain the morphological indexes of tibial plateau bone. Real-time PCR was used to detect the mRNA levels of inflammatory factors, synthetic and catabolic factors in cartilage. Results After high-intensity exercise for four weeks, the inflammation and catabolism of the mouse knee cartilage were enhanced, and the anabolism was weakened. Further study showed that these results were partially reversed after four-week moderate-intensity training. The results of hematoxylin-eosin staining confirmed this finding. Meanwhile, high-intensity exercise reduced the expression of lncRNA H19 in cartilage, while the expression of lncRNA H19 increased after four weeks of moderate-intensity exercise.Conclusion High-intensity treadmill running can cause injury to the knee cartilage in C57BL/6 mice which leads to PTOA and an decrease of lncRNA H19 expression in cartilage. Moderate-intensity exercise can relieve PTOA and partially reverse lncRNA H19 expression.


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.


2018 ◽  
Vol 10 (1) ◽  
pp. 67-75
Author(s):  
Mahmoud Hesar Koshki ◽  
Azam Mollanovruzi ◽  
Amin Rashid Lamir

Summary Study aim: The purpose of this study was to investigate the effect of chronic high-intensity exercise training on hunger, satia­tion, related hormones and weight loss among women who are obese or overweight. Material and methods: The sample group was composed of 25 subjects, divided into two groups: a high-intensity exercise group (n = 15) intensity of 80-90% of maximum heart rate and a non-training control group (n = 10). The blood sample test was performed in two stages of rest, fasted state and before breakfast and an appetite questionnaire was completed. The training procedure was a high-intensity exercise, three sessions a week for twelve weeks and two hours after breakfast. Independent and dependent t-tests were used to analyze the data. Results: The results showed that high-intensity exercise caused a significant loss of weight (p = 0.01) and fat percentage (p = 0.001) and plasma insulin levels (p = 0.03), but it had no effect on hunger and satiation, calorie intake or plasma leptin. Also, it significantly increased the plasma acylated ghrelin (p = 0.04) and maximum oxygen consumption (p < 0.001). Conclusions: Based on the results of this study, it can be noted that high-intensity exercise is suitable for weight loss and not increasing hunger. The lack of calorie intake along with weight loss showed that negative energy balance caused no appetite compensatory responses. Also, high-intensity exercise stimulates physiological responses to increase appetite, but it did not affect the feeling of appetite. In other words, changes in mental and physiological appetite because of high-intensity exercise do not match.


2020 ◽  
Vol 17 (1) ◽  
Author(s):  
Sofia E. M. Andersson ◽  
Elvira Lange ◽  
Daniel Kucharski ◽  
Sara Svedlund ◽  
Karin Önnheim ◽  
...  

Abstract Objective Exercise can improve immune health and is beneficial for physical function in patients with rheumatoid arthritis (RA), but the immunological mechanisms are largely unknown. We evaluated the effect of moderate- to high intensity exercise with person-centred guidance on cells of the immune system, with focus on regulatory cell populations, in older adults with RA. Methods Older adults (≥65 years) with RA were randomized to either 20-weeks of moderate – to high intensity aerobic and resistance exercise (n = 24) or to an active control group performing home-based exercise of light intensity (n = 25). Aerobic capacity, muscle strength, DAS28 and CRP were evaluated. Blood samples were collected at baseline and after 20 weeks. The frequency of immune cells defined as adaptive regulatory populations, CD4 + Foxp3 + CD25 + CD127- T regulatory cells (Tregs) and CD19 + CD24hiCD38hi B regulatory cells (Bregs) as well as HLA-DR−/lowCD33 + CD11b + myeloid derived suppressor cells (MDSCs), were assessed using flow cytometry. Results After 20 weeks of moderate- to high intensity exercise, aerobic capacity and muscle strength were significantly improved but there were no significant changes in Disease Activity Score 28 (DAS28) or CRP. The frequency of Tregs and Bregs decreased significantly in the intervention group, but not in the active control group. The exercise intervention had no effect on MDSCs. The reduction in regulatory T cells in the intervention group was most pronounced in the female patients. Conclusion Moderate- to high intensity exercise in older adults with RA led to a decreased proportion of Tregs and Bregs, but that was not associated with increased disease activity or increased inflammation. Trial registration Improved Ability to Cope With Everyday Life Through a Person-centered Training Program in Elderly Patients With Rheumatoid Arthritis - PEP-walk Study, NCT02397798. Registered at ClinicalTrials.gov March 19, 2015.


2001 ◽  
Vol 204 (16) ◽  
pp. 2861-2872 ◽  
Author(s):  
P. E. GALLAUGHER ◽  
H. THORARENSEN ◽  
A. KIESSLING ◽  
A. P. FARRELL

SUMMARYTo examine cardiorespiratory plasticity, cardiovascular function, oxygen consumption, oxygen delivery and osmotic balance were measured at velocities up to critical swimming speed (Ucrit) in seawater-adapted chinook salmon. We used two groups of fish. The control group had swum continuously for 4 months at a low intensity (0.5 BL s-1)and the other was given a high-intensity training regimen (a Ucrit swim test on alternate days) over the same period of time. Compared with available data for other salmonid species, the control group had a higher maximum oxygen consumption(Ṁo2max; 244μmol O2 min-1 kg-1), cardiac output(Q̇max; 65 ml min-1 kg-1) and blood oxygen content(CaO2; 15 ml O2 dl-1). Exercise training caused a 50% increase in Ṁo2max without changing either Ucrit or CaO2, even though there were small but significant increases in hematocrit, hemoglobin concentration and relative ventricular mass. During swimming, however,exercise-trained fish experienced a smaller decrease in body mass and muscle moisture, a smaller increase in plasma osmolality, and reduced venous oxygen stores compared with control fish. Consequently, exercise training apparently diminished the osmo—respiratory compromise, but improved oxygen extraction at the tissues. We conclude that the training-induced increase in Ṁo2max provided benefits to systems other than the locomotory system, such as osmoregulation,enabling trained fish to better multitask physiological functions while swimming. Furthermore, because a good interspecific correlation exists between Ṁo2max and arterial oxygen supply(Ṫo2max; r2=0.99) among temperate fish species, it is likely that CaO2 and Q̇max are principal loci for cardiorespiratory evolutionary adaptation but not for intraspecific cardiorepiratory plasticity as revealed by high intensity exercise training.


2016 ◽  
Vol 2016 ◽  
pp. 1-12 ◽  
Author(s):  
Kirsten Hötting ◽  
Nadine Schickert ◽  
Jochen Kaiser ◽  
Brigitte Röder ◽  
Maren Schmidt-Kassow

In animals, physical activity has been shown to induce functional and structural changes especially in the hippocampus and to improve memory, probably by upregulating the release of neurotrophic factors. In humans, results on the effect of acute exercise on memory are inconsistent so far. Therefore, the aim of the present study was to assess the effects of a single bout of physical exercise on memory consolidation and the underlying neuroendocrinological mechanisms in young adults. Participants encoded a list of German-Polish vocabulary before exercising for 30 minutes with either high intensity or low intensity or before a relaxing phase. Retention of the vocabulary was assessed 20 minutes after the intervention as well as 24 hours later. Serum BDNF and salivary cortisol were measured at baseline, after learning, and after the intervention. The high-intensity exercise group showed an increase in BDNF and cortisol after exercising compared to baseline. Exercise after learning did not enhance the absolute number of recalled words. Participants of the high-intensity exercise group, however, forgot less vocabulary than the relaxing group 24 hours after learning. There was no robust relationship between memory scores and the increase in BDNF and cortisol, respectively, suggesting that further parameters have to be taken into account to explain the effects of exercise on memory in humans.


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