Weighted blanket research has often revolved around treating mental health conditions. It’s sporadic that I come across research that directly looks at weighted blankets as an intervention for anything else. I was excited to stumble across a study done by Kane et al. (2019), who looked at the effect of weighted blankets on aerobic workout recovery. Expanding research questions to other areas of life, such as workout recovery, is a great way to define the limits and push forward the literature of weighted blankets, and therefore further the progression of a weighted blanket protocol for treatment use.
Positive findings from this study could be applied in various athletic settings such as biathlons, where athletes need to quickly calm down after the cross-skiing portion of the race to complete the shooting portion. Also, in high physical stress situations, people may need to calm down their autonomic nervous system to improve their cognitive functioning. Public information of the study discussed in this article is limited to an abstract, as it was recently presented at a conference, and the researchers are in the process of pursuing publication. I was fortunate to have the lead researcher, Ethan, take the time to talk with me about the research and give me more details and insights.
When chatting with Ethan, I initially asked him how the lab and he became interested in weighted blanket research because it is a niche field and seems focused on mental health benefits. He told me that a few of the lab members were interested in occupational therapy, and deep pressure stimulation interventions (i.e., weighted blankets) are a common intervention used in this line of practice. We also see this in the literature as most weighted blanket research comes from occupational therapists. The connection between weighted blanket and exercise as an idea came from the lab’s interest in occupational therapy and the lab’s research advisor, who was an expert on the autonomic nervous system and exercise physiology. The two areas seemed to have a natural fit, as exercise and anxiety are both mediated through the autonomic nervous system.
There is documented evidence that weighted blankets reduce the sympathetic nervous system –a part of the autonomic nervous system – activity, with anxiety. It was hypothesized that similar calming results found in other areas of weighted blanket research would occur with exercise. The common ground which connects most conditions is stress, and the autonomic nervous system fuels stress, so this connection makes a lot of sense.
Weighted Blankets on Workout Recovery
For this study, Ethan and his team recruited 20 college-age participants. They initially had the participants lie down for 10 minutes, then perform an aerobic exercise (cycling) for 8 minutes. Immediately following the exercise, participants began the workout recovery phase and laid down for 5 minutes, either with or without a weighted blanket. The poster does not state the weight of the weighted blanket used; Ethan told me that the research team decided to use a 20-pound weighted blanket on all participants based on previous research’s positive outcome when using a one-size-fits-all approach. There was a discussion of individualizing the weighted blankets and even creating a weighted blanket, but they felt comfortable with using a single weight based on previous research.
Data were collected during the workout recovery phase at 1-minute, 3-minute, and 5-minute intervals; data collected included heart rate variability, electrodermal activity (sweat), heart rate, and a questionnaire on anxiety. The physiological data was used to measure the autonomic nervous system’s response to the weighted blanket, and the questionnaire was (obviously) used to measure psychological effects. In sum, the data did not show any significant differences in the autonomic nervous system response in workout recovery between times where a weighted blanket was used and was not used. However, participants reported an improvement in anxiety when the weighted blanket was used. So, what happened?
What do we know about the Autonomic Nervous System and Workout Recovery?
Ethan told me that the results weren’t completely unexpected because although exercise and anxiety are mediated through the same system, exercise has a global response in the body and activates many more systems such as the muscular system, respiratory system, and circulatory system. Due to the more multifaceted bodily involvement with exercise, workout recovery is not only controlled by the autonomic nervous system, and other systems may have confounded the potential effects of the weighted blanket.
Aside from the global bodily response that may have caused the lack of significance in results, there is also a component of the autonomic nervous system that is different with exercise, and this too may have contributed to no significances found. As I’ve learned about the autonomic nervous system, I had the assumption that it responded the same way to anything that triggered it. With this reasoning, I believed anything that triggered the sympathetic nervous system would send the body into fight or flight mode. While this is generally true, I have learned that there’s a bit of a difference with exercise.
While anxiety activates the sympathetic nervous system to “fight or flee” a situation, exercise activates the sympathetic response in a different way. By exercising for an extended period, the heart rate will need to increase to adjust to the stress being put on the body, and the sympathetic nervous system will kick in to allow your body to adapt to the exercise-related stress you are putting it under. In cases of anxiety, it seems as though the emotion (i.e., panic) triggers the body to prepare for the action of fight or flight by sending signals to hype up the body.
A final consideration relates to the type of participants recruited. The participants recruited were not identified as regular exercisers or non-exercisers, and this can impact workout recovery time and the results. Ethan stated in the interview that this was something they thought of as they were going back through and writing up the results and is something he would be interested in for future research.
Confirmation that Weighted Blankets can Help with Anxiety
Although the physiological results yielded insignificance, the psychological component embedded in the anxiety questionnaire reaffirmed that weighted blankets do have an impact on anxiety. When I initially read the poster and saw that there was a decrease in anxiety, I thought, “obviously, exercise is known to produce endorphins which provide relief from anxiety.” However, after some digging, I found that it takes about 30 minutes of consistent exercise for the endorphins to be emitted, although this time will vary from person to person, and it is also based on the intensity of the activity being performed.
In this study, the participants only exercised for 8 minutes. Thus, it is unlikely that endorphins caused a shift in anxiety. I asked Ethan about how they chose the time frame for exercise. He said initially they trialed 15-minute exercise intervals, but participants became very sweaty, and this hindered EDA data from being collected. They also needed a long enough time to collect HRV data, as at least 6 minutes of steady exercise is required to have enough data. Eight minutes allotted them a good window and gave them the data needed for this preliminary study.
Future Considerations of Weighted Blanket and Workout Recovery Research
As Ethan discussed in the interview, this study is a starting point, and although the results were insignificant, there are more ways that the methodology could be changed, which could yield a different result. A suggestion Ethan gave was using direct autonomic nervous system measurements rather than the proxy measurements used in this study. Also, experimenting with various participants who may exercise more or less, different weighted blanket weights, and different exercise intensities. This research acts as a starting point for other teams to piggy-back off of. At the very least, Ethan and his lab mates’ research has replicated the findings that weighted blankets play a role in the mitigation of anxiety.