Effect of 9 weeks continuous vs. interval aerobic training on plasma BDNF levels, aerobic fitness, cognitive capacity and quality of life among seniors with mild to moderate Alzheimer’s disease: a randomized controlled trial

Abstract

Background: Evidence suggests that aerobic-type training confers physical benefits and appears to contribute positively to brain health. This study aims to compare the effect of 9-weeks continuous (CAT) to interval aerobic training (IAT) on brain derived neurotrophic factor (BDNF) plasma level, aerobic fitness, cognitive performance, and quality of life among senior with Alzheimer's disease (AD). Methods: 52 participants were randomly allocated into three groups (CAT n = 14; IAT n = 17; and Controls n = 21). CAT and IAT consisted of 18 sessions of 30-min cycling, twice a week, over 9 weeks. During the same period, controls were engaged in interactive information sessions. Plasma BDNF level; aerobic fitness parameters (Metabolic equivalent task-METs; Maximal Tolerated Power-MTP); functional capacities (6-Minute Walk Test-6MWT); cognitive performance (Mini Mental State Examination; Rey auditory verbal learning test; and digit span test) and quality of life (Quality Of Life of Alzheimer's Disease scale-QoL-AD) were measured in all participants at baseline and 9 weeks later. A third plasma BDNF level was quantified following a 4 weeks detraining. Results: No significant change was measured in terms of plasma BDNF level and cognitive performance after interventions, in all groups compared to baseline. After 9 weeks, CAT and IAT significantly improved aerobic fitness parameters compared to controls (METs: + 0.6 and + 1.0 vs. + 0.4; MTP: + 16 watts and + 20 watts vs. + 10 watts; and functional capacities (6MWT: + 22 m and + 31 m vs.-40 m). Compared to controls, QoL-AD after CAT was improved (+ 2 points; p = 0.02). Conclusions: Neither aerobic exercise modalities significantly modified plasma BDNF levels and cognitive performances. CAT and IAT enhanced aerobic fitness and functional capacities in AD patients and CAT their QoL.

Effect of Physical Exercise on Cognitive Function of Alzheimer's Disease Patients: A Systematic Review and Meta-Analysis of Randomized Controlled Trial

“…However, 45% of the studies in mixed exercise did not show a positive effect of the intervention. Moreover, the least amount of exercise in all studies was 540 min ( 48 ), and the most were 7,800 min ( 54 ), and neither study found a significant cognitive improvement effect. Therefore, this means that the relationship between the amount of exercise and the effect of exercise is not clear.…”

“…A total of twenty-two RCTs involving 1,647 AD participants (age 77.1 ± 6.3 years) were included in the study for review. The included studies were from sixteen countries, namely Brazil ( 16 , 45 , 47 ), France ( 18 , 46 , 48 ), USA ( 50 , 54 , 56 ), Italy ( 13 , 53 ), Nigeria ( 17 ), Netherlands ( 49 ), Denmark ( 11 ), Germany ( 15 ), Egypt ( 12 ), Finland ( 19 ), Iran ( 51 ), Albania & Spain ( 14 ), Sweden ( 52 ), Australia ( 20 ), and China ( 55 ). Participants were from the community, social centers, social clubs or individuals, memory clinics, or hospitals.…”

“…The study interventions contained aerobic, resistance, stretching, or mixed exercise (aerobic, resistance, balance, and stretching exercises). Nine studies performed a single aerobic training session, including supervised aerobic, walking, or cycling training ( 11 – 13 , 48 , 50 , 53 – 56 ). Eleven studies used mixed exercise modalities, combining aerobic, resistance, balance, stretching, or cognitive training ( 16 – 20 , 45 – 47 , 49 , 51 , 52 ).…”

Exercise-Induced Benefits for Alzheimer’s Disease by Stimulating Mitophagy and Improving Mitochondrial Function

“…Previous studies have demonstrated that appropriate low-intensity exercise is more effective than highintensity exercise in protecting and restoring the aging brain in rats (Kim et al, 2003). In clinical trial cases, the results present a wide variation depending on the type and intensity of exercise (Enette et al, 2020). Thus, there are still many questions about the potential benefits of exercise in AD animal models and human patients.…”

The Endocannabinoid System as Modulator of Exercise Benefits in Mental Health

“…Additional efforts have been achieved by using non-pharmacological approaches for treating mental illnesses, including phototherapy, nutritional supplements, and physical exercise [ 11 - 14 ]. In this regard, multiple findings have demonstrated that physical activity and exercise promote health benefits in patients with psychiatric disorders [ 15 - 18 ]. Exercise influences multiple neurobiological networks, including the endocannabinoid system [ 19 - 22 ], therefore, it is likely that this endogenous signaling arrangement might influence the effectiveness of exercise as a treatment for managing mental disorders.…”