Optimal exercise modality and dose to improve depressive symptoms in adults with major depressive disorder: A systematic review and Bayesian model-based network meta-analysis of RCTs.

Depression is a growing public health concern, and exercise is an adjunctive treatment modality to improve depression, but the optimal form of exercise and the optimal dose are still unclear. This systematic review examined the efficacy of four major types of exercise (aerobic, resistance, mixed, and mind-body) on depression, as well as the dose-response relationship between total and specific exercise and depressive symptoms. We included randomized controlled trials that included participants aged 18 years or older with a diagnosis of major depressive disorder or a depressive symptom score above a threshold as determined by a validated screening measure, implemented one or more exercise therapy groups, and assessed depressive symptoms at baseline and follow-up. Forty-six studies (3164 patients) were included in the meta-analysis. Aerobic (standardised mean difference (SMD) = -0.93; 95% CI: -1.25 to -0.62) and mind-body exercise (SMD) = -0.81; 95% CI: -1.19 to -0.42) improved depressive symptoms better compared to controls, followed by mixed (SMD = -0.77; 95% CI: -1.20 to -0.34) and resistance exercise (SMD = -0.76; 95% CI: -1.24 to -0.28). This dose-response meta-analysis showed a U-shaped curve between exercise dose and depressive symptoms. The minimum effective dose was estimated to be 320 metabolic equivalent (METs) -min per week and the optimal response was 860 METs-min per week. These findings lead us to advocate that clinicians carefully select the appropriate dose of exercise based on the patient's individual characteristics and needs, in conjunction with psychological care interventions.

The Best Exercise Modality and Dose to Reduce Glycosylated Hemoglobin in Patients with Type 2 Diabetes: A Systematic Review with Pairwise, Network, and Dose-Response Meta-Analyses.

BACKGROUND: Persistently elevated glycosylated hemoglobin (HbA1c) is associated with a higher risk of long-term vascular complications. OBJECTIVE: We evaluated the effect of different exercise modalities and doses on HbA1c levels in patients with type 2 diabetes. METHODS: A systematic search for randomized controlled trials involving exercise interventions in patients with type 2 diabetes was conducted across seven electronic databases, encompassing data from their inception up to October 2023. Two independent reviewers assessed the quality of the literature. Pairwise, network, and dose-response meta-analyses using the random-effects model were conducted to analyze the effect of exercise on HbA1c levels. RESULTS: A total of 85 randomized controlled trials with 5535 participants were included. The network meta-analysis showed that high-intensity interval training (HIIT) has the highest ranked (MD = - 0.78% [- 8.50 mmol/mol]; 95% CrI: - 1.04, - 0.51), followed by combined aerobic and resistance exercise (CE) (MD = - 0.54% [- 5.90 mmol/mol]; 95% CrI: - 0.69, - 0.40), yoga (MD = - 0.45% [- 4.92 mmol/mol]; 95% CrI: - 0.77, - 0.13), and continuous aerobic exercise (CAE) (MD = - 0.42% [- 4.58 mmol/mol]; 95% CrI: - 0.54, - 0.30). In addition, a significant improvement in HbA1c levels can be observed when the total exercise dose reaches 840 metabolic equivalent of tasks-min/week. CONCLUSIONS: There was low-quality evidence that HIIT, CE, yoga, and CAE may be effective treatment modalities for improving HbA1c in patients with type 2 diabetes, and there was no significant difference in efficacy. Moreover, a non-linear dose-response relationship was found for total exercise and HbA1c levels. Future research should further investigate the specific effects of different exercise doses on HbA1c levels in patients with type 2 diabetes and provide a more personalized exercise prescription.

The Best Exercise Modality and Dose for Reducing Pain in Adults With Low Back Pain: A Systematic Review With Model-Based Bayesian Network Meta-analysis.

OBJECTIVE: To quantify the dose-response relationship between overall and specific exercise modalities and pain, in patients with nonspecific chronic low back pain (LBP). DESIGN: Systematic review with Bayesian network meta-analysis. LITERATURE SEARCH: We searched the Medline, Embase, Web of Science, Cochrane Library, Scopus, and SPORTDiscus databases from inception to June 2023. STUDY SELECTION CRITERIA: We included randomized controlled trials of exercise interventions in adults with nonspecific chronic LBP and at least 1 pain outcome reported at the main trial end point. DATA SYNTHESIS: A random-effects network meta-analysis was conducted. We assessed risk of bias using the Cochrane Risk of Bias Tool 2.0, and used the GRADE approach to judge the certainty of evidence for each outcome. RESULTS: Eighty-two trials were included (n = 5033 participants). We found a nonlinear dose-response relationship between total exercise and pain in patients with nonspecific chronic LBP. The maximum significant response was observed at 920 MET minutes (standardized mean difference = -1.74; 95% credible intervals: -2.43, -1.04). The minimal clinically important difference for achieving meaningful pain improvement was 520 MET minutes per week. The dose to achieve minimal clinically important difference varied by type of exercise; Pilates was the most effective. The certainty of the evidence was very low to moderate for all outcomes. CONCLUSION: The dose-response relationship of different exercise modalities to improve pain in patients with nonspecific chronic LBP had a U-shaped trajectory and low- to moderate-certainty evidence. The clinical effect was most pronounced with Pilates exercise. J Orthop Sports Phys Ther 2024;54(5):1-13. Epub 8 March 2024. doi:10.2519/jospt.2024.12153.

Physical activity on executive function in sedentary individuals: Systematic review and meta-analysis of randomized controlled trials.

Physical activity has been demonstrated to promote cognitive performance. However, the relationship between physical activity and executive function (EF) in sedentary individuals is not fully understood. This meta-analysis examined the impact of physical activity on EF in sedentary individuals and evaluated potential moderators of the relationship between physical activity and EF. In accordance with the PRISMA guidelines, the electronic databases MEDLINE, Embase, PsycINFO and Web of Science were searched. Included studies had to report sedentary individuals randomized to either a physical activity group or a control group. Subgroup analyses of EF sub-domains, exercise prescription and age were conducted alongside the overall meta-analysis. Thirteen RCT studies were included, with a total of 752 participants. Results showed a small to moderate beneficial effect of physical activity on EF (SMD = 0.24, 95% CI 0.08 to 0.40). In subgroup analysis by EF sub-domains, physical activity enhanced inhibitory control (SMD = 0.38, 95% CI 0.12 to 0.63) and working memory (SMD = 0.22, 95% CI -0.05 to 0.49), but not cognitive flexibility (SMD = 0.11, 95% CI -0.18 to 0.41). Interventions with an intervention length > 12 weeks improved overall EF (SMD = 0.26, 95% CI 0.06 to 0.46), but intervention length ≤ 12 weeks did not (SMD = 0.20, 95% CI -0.08 to 0.47). Interventions with session time ≥ 45 minutes improved overall EF (SMD = 0.47, 95% CI 0.22 to 0.77), but session time < 45 minutes did not (0.17, 95% CI -0.11 to 0.44). Physical activity improves EF for older adults (age ≥ 60 years) (SMD = 0.25, 95% CI 0.08 to 0.42), but not for younger individuals (age < 60 years) (SMD = 0.17, 95% CI -0.25 to 0.59). Overall, physical activity has a beneficial effect on EF in sedentary individuals, although the influence may be domain specific and influenced by exercise prescription and age. These findings have practical implications for those seeking to improve EF in sedentary individuals through physical activity.

Effects of acute exercise with different modalities on working memory in men with high and low aerobic fitness.

OBJECTIVES: This study aimed to determine the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on working memory in individuals with high and low aerobic fitness. DESIGN: The protocol adopted a between-subjects crossover design. METHODS: Forty healthy male college students (mean age = 19.59 ± 1.00 years) were assigned to high fitness (n = 20) or low fitness (n = 20) groups based on their estimated maximum oxygen consumption (VO2max) in the 20 m shuttle run test. All participants were instructed to engage in three acute exercise interventions (10 min HIIE, 20 min HIIE, 20 min MICE) and a reading control intervention on separate days in a randomized order. A spatial 2-back task was performed before and after each intervention to assess working memory. RESULTS: Analyses of the 2-back task performance revealed that the working memory of high and low fitness participants benefited from different modalities of acute exercise. Specifically, reaction time in the 2-back task was significantly shorter after 20 min HIIE compared to pre-exercise in high fitness participants, whereas low fitness participants had significantly faster reaction time in the 2-back task after 20 min MICE and 10 min HIIE relative to pre-exercise. CONCLUSIONS: The effects of acute aerobic exercise on working memory are modulated by a combination of exercise modality and aerobic fitness. This finding has important implications for providing experimental evidence that participants choose appropriate exercise to undertake based on their level of aerobic fitness to improve cognitive performance.

Effects of Acute Exercise on Cognitive Flexibility in Young Adults with Different Levels of Aerobic Fitness.

This study aimed to evaluate the effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on cognitive flexibility in young adults with differing levels of aerobic fitness. Sixty-six young adults were grouped into high- and low-fit groups based on their final running distance on the 20 m Progressive Aerobic Cardiovascular Endurance Run (PACER) test. Individuals participated in a 10 min HIIE, a 20 min HIIE, a 20 min MICE, and a control session (reading quietly in a chair) in a counterbalanced order. The more-odd shifting task was completed before and approximately 5 min after each intervention to assess cognitive flexibility. The results showed that young adults with a high fitness level gained greater benefits in terms of switch cost from the 20 min HIIE, while low-fitness participants benefited more from the 10 min HIIE and the 20 min MICE. These findings suggest that aerobic fitness may influence the effect of acute HIIE and MICE on cognitive flexibility. Young adults should consider individual fitness level when adopting time-effective and appropriate exercise routines to improve cognitive flexibility.

The Immediate and Sustained Effects of Moderate-Intensity Continuous Exercise and High-Intensity Interval Exercise on Working Memory.

This study investigated the immediate and delayed effects of moderate-intensity continuous exercise (MICE) and high-intensity interval exercise (HIIE) on working memory. Fifty healthy young adults (mean age = 19.96 ± 1.03 years) engaged in (1) a MICE session, 20 min of continuous running on a treadmill at an intensity of 40-59% of heart rate reserve (HRR); (2) a HIIE session, 10 sets of 1 min running at an intensity of 90% HRR, interspersed by 1 min self-paced walking at 50% HRR; and (3) a control session, resting in a chair and reading books for 24 min. A spatial 2-back task was performed to assess working memory before, immediately after and 30 min after each intervention. Reaction time in the 2-back task was significantly reduced immediately after both MICE and HIIE interventions. The enhanced working memory associated with HIIE sustained for 30 min after the exercise, whereas the beneficial effects associated with MICE returned to the pre-exercise level at 30 min after the exercise. These results suggest that although both MICE and HIIE enhance working memory in young adults, the positive effect sustains longer in HIIE than that in MICE. The current study extends the existing knowledge base by suggesting that improvements in working memory with HIIE last longer than with MICE.

Comparison of the Sustainability Effects of High-Intensity Interval Exercise and Moderate-Intensity Continuous Exercise on Cognitive Flexibility.

This study examined the immediate and sustained effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) on cognitive flexibility in young adults. Participants (n = 56) engaged in (1) a session of HIIE, involving 10 sets of one-minute treadmill running at an intensity targeting 90% heart rate reserve (HRR) interspersed with self-paced walking at 50% HRR; (2) a session of MICE, involving a 20 min treadmill running at an intensity of 40-59% HRR; and (3) a control session, involving 24 min of resting on separate days in a counterbalanced order. Using a more-odd shifting task, cognitive flexibility was assessed before the intervention (t0), immediately after the session (t1), and then at 30 min (t2) after the session. During the more-odd shifting task, the switch cost of response time (RT) immediately after the HIIE was significantly reduced compared to that before exercise, suggesting beneficial effects on cognitive flexibility. Additionally, the impacts of HIIE were maintained for 30 min post-exercise. However, improved cognitive flexibility was not observed until 30 min after the MICE intervention. HIIE might represent a time-efficient approach for enhancing cognitive flexibility.

Sustained Effects of High-Intensity Interval Exercise and Moderate-Intensity Continuous Exercise on Inhibitory Control.

This study examined the immediate and sustained effects of high-intensity interval exercise (HIIE) and moderate-intensity continuous exercise (MICE) bouts on inhibitory control in young adults. Participants (n = 41) engaged in (1) a session of HIIE, involving 10 one-minute runs on a treadmill at an intensity targeting 85-90% HRmax interspersed with self-paced walking at 60% HRmax; (2) a session of MICE, involving a 20 min run on a treadmill at an intensity of 60-70% HRmax; and (3) a control session, involving 24 min of resting on separate days in a counterbalanced order. Using a flanker task, inhibitory control was assessed before the intervention (t0), immediately after the session (t1), and then at 30 min (t2), 60 min (t3), and 90 min (t4) after the session. During the flanker task, the response time (RT) for incongruent trials immediately after HIIE was significantly shortened compared to that before exercise. This shortened RT was sustained for 90 min post-exercise during recovery from HIIE. Interference scores of RT were also reduced after HIIE, benefitting inhibitory control, and were maintained for 90 min post-exercise. Reduced accuracy interference scores were recorded following HIIE compared to the control session. Improvements in inhibitory control elicited by HIIE were sustained for at least 90 min post-exercise. In contrast, an improvement in inhibitory control was not observed during the MICE session. HIIE might represent a time-efficient approach for enhancing inhibitory control.