Norman Swan: Hello and welcome to the Health Report with me Norman Swan. An astounding statistic for you: There are more young people alive today than ever before in human history and we know less about them than any other age group. It’s a global bulge probably larger than the post war baby boom in Australia and other rich countries. That’s later, after we’ve dealt with a more adult issue: keeping your brain in order.
Could building your muscles build your brain or at least slow it from falling apart? That’s the tantalising suggestion from a randomised trial released a few days ago where strength training improved the thinking ability of people whose memory was beginning to go. Teresa Liu-Ambrose is at the Brain Research Centre at the University of British Columbia.
Teresa Liu-Ambrose: We have done studies in the past in otherwise healthy older adults and found that resistance training was beneficial for cognitive function and so what we’ve done is extend our research and looked at the effect of both strength training and aerobic training in individuals with mild cognitive kind of impairments. We do know that they have a greater risk of developing dementia over the next 5 years.
Norman Swan: And when you say cognitive impairment, their memory is not as good as it used to be, particularly their short term memory and they’re thinking a bit more slowly than they otherwise would have a few years ago.
Teresa Liu-Ambrose: And for those who were in our study the two primary areas that we really noticed a significant deficit in was memory but also the executive components your ability to make decisions well and also to plan and also to multi task.
Norman Swan: So tell me about the study.
Teresa Liu-Ambrose: It was a 6 month trial and what we did was randomise them to one or three groups. The control group were still exercising. They came to our centre twice a week. They participated in stretching but also in the functional strength exercises as well. So they did do lunges or squats so fairly active. The second group was a twice a week walking group, they would walk either outside or indoors depending on the weather if you live in Vancouver and over time we progressed and so we always monitored their heart rates, ensured that they were working moderately hard and introduced urban poling as well just to add complexity to their program.
Norman Swan: Urban poling: this is walking with poles, get your speed up a little bit without falling over.
Teresa Liu-Ambrose: Yes. It is quite a different movement pattern. There is a technique underlying it. We did purposely introduce that so that there is some component of cognitive learning involved and the reason we did that was because for our third group which is the strength training we have felt very strongly that it does have a significant degree of learning involved. We’re always teaching people how to meet proper form while they’re lifting the weights and as they’re doing strength training are always monitoring how many reps, how many sets they’re doing, so we try to equalise a cognitive loading component in the walking program.
Norman Swan: And what did the strength training group get?
Teresa Liu-Ambrose: They used machines to increase their muscle strength, we worked on both the upper and lower bodies and it was a mix between using machines, free weights and a smaller functional movement, so also did lunges and squats, but we would increase loading on top of just their body weight.
Norman Swan: And was it progressive, so that week by week they built up their weights?
Teresa Liu-Ambrose: Yes, and so was the walking group. We monitored people quite closely, so the strength training, once an individual could lift a weight eight times for two sets with no problem we would always increase the weight.
Norman Swan: And this was twice a week?
Teresa Liu-Ambrose: Twice a week yes.
Norman Swan: And this went on for 6 months, how much difference was there just physically in the three groups at the end of the time compared to the beginning, just so that you know you actually got a training effect?
Teresa Liu-Ambrose: For the strength training group for all the participants we saw quite drastic increases in their loading. For most people we start off anywhere from 2 pounds to 5 pounds for example biceps on average towards lifting up to 15 pounds or 20 pounds per arm.
Norman Swan: My goodness.
Teresa Liu-Ambrose: Yes, it’s quite heavy we actually just had a participant come back and she was still able to lift 15 pounds and she’s rather a small lady. And for the aerobic training group we saw amazing increases as well.
Norman Swan: So let’s get to the money – what happened to their thinking ability?
Teresa Liu-Ambrose: Well what we saw was that as compared to the control group the resistance training group demonstrated a significant improvement in the area of executive function, their ability to make the appropriate decision given a particular circumstance. And the second component was we saw that they had better associative memory. Associative memory is somewhat different than just simply remembering an item. An item memory component would be: do you remember someone’s name? Associative memory would be in the context of remembering the name and tie it to the face and we saw an improvement in the resistance training group for the associative memory.
Norman Swan: Bring on the weights!
Teresa Liu-Ambrose: Yes, and that was quite exciting for us because in terms of relevance to dementia, in particular Alzheimer’s disease, changes in associative memory occurs quite early on and also executive function ability to make the appropriate decision given circumstance, that cognitive process is also a significant predictor of whether someone will transition from a mild cognitive impairment to dementia, so we were quite excited about that.
Norman Swan: Now you might have been excited as a researcher, but did they notice the difference, because one of the controversies in this whole area of testing an improvement, particularly in medications for dementia and cognitive impairment, is that the researchers get excited because their tests are positive, but nobody else notices it, it doesn’t make a difference to their lives?
Teresa Liu-Ambrose: Sure and that’s a great question and I would talk to a participant today and what she shared with us is that she did notice there was a difference in her abilities, her example was that before she would always have to write everything down, she had a system of coping but she did find that once she was in the study that she did have the confidence to not always have to write things down and still felt that she was remembering and operating well. It may not always be as isolated as I feel that my memory is better but anywhere from I feel more confident of myself, I feel I could do more, or I can meet the challenges thrown at me much better than before.
Norman Swan: And how long did it last?
Teresa Liu-Ambrose: For this particular study we didn’t follow them up, we didn’t have the funds unfortunately. But in our prior study in otherwise healthy older adults where we did follow them a year out from the end of the trial, we actually could see that the benefits did persist and mainly because people remained active.
Norman Swan: You implied earlier that one of the benefits here you assume comes from the fact that they actually have to learn new skills, count the reps, push themselves harder and therefore it’s not just blind exercise, there’s a thinking element in the exercise as well, testing your brain. The question here is somebody listening to this whose got an elderly parent who’s beginning to lose their memory and this is an option you know what you often say when you’re doing it for cardio- vascular, you’re doing it for your heart you would say to somebody look as long as you go for a walk and you do ten minutes of muscle strengthening you could just be leaning against the bench and doing press ups and doing some dips and so on, you don’t need to get dressed in lycra and go to the gym. But what I hear from you is that you might actually have to go to the gym for this benefit because you actually need a trainer to teach you new exercises, monitor things along with you, make sure you progress, that the trainer is actually an element here which is quite important.
Teresa Liu-Ambrose: Your journey to focus on what you’re doing, it’s not something you are just doing quite blindly and not paying attention to the task at hand so yes, I agree whether that is facilitated by another individual or you’re reminding yourself to focus on the task I think that has a huge factor. And the second component is that it needs to be progressive. If you look at previous literature in strength training and cognition there has been a number of other studies. The ones that tend to have a negative effect are not progressive in nature, while if you look at studies that seem to be positive, the component is always progressive. Whether that is facilitated by a dedicated trainer or even a family member I think for older adults having someone to support them in adhering to exercise is always important. Even for walking to maximise the benefit based on what we know it does need to be again moderate intensity and progressive.
Norman Swan: So you can’t just rest on your laurels?
Teresa Liu-Ambrose: No. I think you always need to try to move forward and to the best of your ability.
Norman Swan: Teresa Liu-Ambrose is at the University of British Columbia in Vancouver where she also works in the Centre for Hip Health and Mobility.
Lindsay S et al. Resistance Training Promotes Cognitive and Functional Brain Plasticity in Seniors With Probable Mild Cognitive Impairment. Arch Intern Med 2012;172(8):666-668