We have all been told that exercise is good for us. It energizes and stimulates our body. It can even make us smarter. However, it turns out that not all types of physical exercises produce the same benefit to our cognition. This sounds rather odd because I, at least, always thought that no matter what the exercise is, it is equally as beneficial to our intellects. But, this is not necessarily the case.
According to research by Finnish researchers, cited by Stuff, sustained aerobic exercise is the way to go if you seek to catalyze your learning (by generating new hippocampus neurons). The study also looked over the neurobiological responses to HIIT cardio (intense exercises performed in short time intervals) and weightlifting (aka resistance training), but neither produced significant results compared to sustained aerobic exercise. In fact, the results from participants who completed resistance training were no more different than those of sedentary participants (control group)! I also thought this was a unique finding because weight lifting requires the lifter to make a mind-muscle connection during exercises to induce greater muscle growth. Since the brain is an important organ key to weight lifting, wouldn't it make more sense that weight lifting would be more beneficial to the brain? For me, weight lifting has definitely recruited more of my mind since I have to focus on my form as well as establish a mind muscle connection, whereas steady cardio barely recruited my brain.
The scientists proposed that aerobic exercise specifically increases blood flow in a part of a brain called the dentate gyrus, which promotes hippocampus growth. Another source claims that sustained aerobic exercise specifically produces a compound called irisin, which can help activate genes involved in brain cognition. Either way, this debate needs to be further researched.
A question to consider here: does HIIT and resistance training not allow blood flow in the hippocampus area? We still do not know the biological basis behind why sustained aerobic exercise is better for our hippocampal region, but this study definitely gives us a glimpse into it.
Of course, this does not mean we should just ditch the weights and our quick 20 minute HIIT cardio sessions! Who knows, maybe resistance training and HIIT can improve other regions in our brain. They also bring their own physical health benefits to the table. Resistance training gives a great advantage as it develops muscle and promotes bone density. HIIT also develops muscle compared to endurance aerobic trainings. It is also important to keep in mind that excessive exercise will increase cortisol levels, which can negatively impact our cognition.
The results of this study are not exclusive. There have been other studies that showed that weight lifting at least twice a week can help reduce the brain's aging process. So I think the logical conclusion to make would rather be that these different exercises can impact our brains in different ways. Each exercise has its own unique benefits.