中南大学最新研究登上Cell头条：运动太多会变笨？揭秘过度运动损害大脑认知的新机制

Core Viewpoint - A recent study from Central South University Xiangya Hospital highlights that excessive vigorous exercise can impair cognitive function through a muscle-derived mitochondrial vesicle called otMDV, emphasizing the importance of maintaining moderate exercise intensity for brain health [4][7]. Group 1: Relationship Between Exercise and Cognitive Function - The relationship between exercise and health follows an "inverted J-shaped" curve, indicating that moderate exercise promotes health, while excessive exercise can lead to adverse effects such as muscle fatigue and cardiovascular dysfunction [6]. - The study analyzed data from over 300,000 participants in the UK Biobank, revealing a "J-shaped" relationship between exercise and cognitive function, where moderate exercise is beneficial, but exceeding a certain threshold leads to cognitive decline [9]. - The optimal "dose" of vigorous exercise is approximately 1216 MET-min per week; exceeding this threshold results in a decline in cognitive function, a pattern validated across different age and gender groups [9]. Group 2: Mechanisms of Cognitive Impairment Due to Excessive Exercise - Excessive vigorous exercise leads to lactate accumulation in muscles, stimulating the secretion of otMDV, which can cross the blood-brain barrier and interfere with mitochondrial function in hippocampal neurons, crucial for learning and memory [11]. - OtMDV disrupts synaptic function through two mechanisms: first, it binds to the mitochondrial anchoring protein Syntaphilin, preventing normal mitochondria from anchoring at synapses; second, the mtDNA carried by otMDV activates the cGAS-STING signaling pathway, inhibiting the transport of the neuron’s own mitochondria to energy-demanding synaptic sites [13][14]. - These mechanisms collectively lead to a synaptic energy crisis, resulting in synaptic loss and cognitive decline [15]. Group 3: Human Study and Implications - A clinical trial involving 40 regular exercisers divided into moderate and excessive exercise groups showed that the excessive exercise group had significantly higher levels of PAF+ MDV in their blood, with decreased neural activity in the hippocampus and poorer performance in fluid intelligence and digit memory tests [18]. - The level of PAF+ MDV was directly correlated with the degree of cognitive decline, indicating the real risks of excessive exercise in humans [18]. Group 4: Potential Strategies for Prevention and Treatment - The research team developed neutralizing antibodies targeting the PAF protein, which effectively blocked the cognitive impairment caused by otMDV in animal experiments, suggesting a new avenue for treating cognitive disorders related to excessive exercise [20]. - Key factors include controlling the duration of intense exercise, with short bursts (15-45 minutes) causing only temporary lactate elevation, while prolonged intense exercise (over 60 minutes) leads to sustained high lactate levels and otMDV secretion [20]. - The study emphasizes the importance of moderation in exercise, listening to bodily feedback, diversifying exercise routines, and ensuring adequate rest and recovery [20].