Let's start here:
My background is exercise physiology, in which I hold my Master's degree. I have been in a laboratory setting and conducted (a tiny bit of) research. I have taken classes on how to conduct, read, and interpret data from research. I've read BOAT LOADS of research. And yet, I will be the first to admit the gaps in my knowledge. The more I read, the less I feel that I know for certain.
What I'm offering here is how I think about research and how I apply what I read (because yes, I still read research) to my classes and clients. I'm also, for the most part, very specifically talking about the research that has been done on perinatal populations or, pregnancy and postpartum. And, if you're reading this, you likely have some interest in this specialty, too.
Firstly, research rarely PROVES anything. What research does is accept or reject a hypothesis (an educated guess) that a research team has made. Research answers questions and tells us if we're on the right track (or not). Research gives us hints about how things work. Basically, research makes SUGGESTIONS- whether those be positive or negative suggestions... but, suggestions nonetheless. And, when we have a lot of research (or a large piece of research that is done REALLY WELL) that offers the same suggestion, or accepts the same hypothesis, we tend to accept this as popular opinion, mainstream, or "proof" that it is an actuality of life.
For instance, it's a widely accepted opinion that second hand smoke causes cancer. We accept this as a reality. There are people that argue this is not true (trust me, there are). But, we have enough scientific evidence to ban cigarettes from places where people would be inhaling this crap in concentrated amounts because we have done enough research to say, "yes, eureka, we believe this".
However, sometimes, these actualities CAN and do change. The world was once flat, muscle soreness used to be caused by lactic acid build up, and chronic fatigue was once thought to be caused by a virus... research gets retracted, researchers goof up, and scientists find new information that changes the way we think. And, this happens more often than we know.
Research is not perfect. In fact, it's kind of inherently fallible because people are inherently fallible and people conduct research. This doesn't mean we shouldn't trust research. We just need to be really cautious with how we apply research and how much we hide behind it and use it to PROVE some point that we vehemently agree with. It's really easy to find a single research paper to prove almost any point but, can we find five, ten, or twenty articles to back our ideas?
One article does not a proof make (unless the number of people studied is HUGE and spans many many years). I would even hesitate to say something is proven based on 5 articles (based on the variables of the research being conducted). Would you trust an article if only one person had been tested? How about one research paper testing 10 people? Or, two studies of five people each? What about 10 studies that looked at three people each?
I think you get my point. Paying attention to the sample size (the number of subjects in the research) and number of times similar research has been conducted is important. Unfortunately in the perinatal world the research is really lacking. There is insufficient evidence to PROVE a lot of things we take for fact.
Some of this is due to the fact that the research can't be done: a prenatal population is considered high risk or special condition. In doing exercise science research where we don't know the outcome, we could potentially put mom and baby at risk. This is a big no no with an Ethics Committee. Ethics committees were created to approve or deny potential research (prior to it being conducted) to make sure that there is no inherent harm in that research. And if there is any chance of harm (say to a fetus), sorry pal, try again. This is why you see SO much research where yoga and walking are the intervention and less research on pregnant women working out around their VO2max.
WE JUST DON'T KNOW.
Then, we need to think in terms of variability. Let's use the example of morning sickness for the rest of this article. We are all different and thus, almost EVERY pregnancy is different. During my first pregnancy, working out made my morning sickness worse. I was puking and exhausted and the exercise only further added to the fatigue but during the second, it changed. Despite still puking, I was able to move a little and get a bit of relief from that movement. Look at that staggering difference between my TWO pregnancies. What if I had participated in a research study during my first pregnancy but not my second? How would that have contributed to or changed the body of evidence for exercise and morning sickness? Now apply this line of thinking to all of the people you've known who have been pregnant. How much did their experiences vary. Can one study of 50 women really capture that variability?
We also have to consider what is being measured and how it is being measured. In the case of morning sickness, is it something truly measurable like liters of vomit or is it self-reporting (women rating how they feel on a 1-10 scale pre and post intervention)? Self reporting, as you can imagine has a HUGE degree of variability.
For instance what if a researcher is looking a group that exercises versus a group that is sedentary and finds that the exercise group does indeed experience a reduction in their nausea and concludes it is because of exercise.
Don't you have questions? I DO! I DO! I DO! Did everyone do the same movement? Was their intensity the same? Did they work out for the same amount of time? How did they measure and "improvement" in symptoms. What was the baseline measurement of nausea? How do we know that two people's nausea is the same? What does improvement mean? Does exercise completely negate morning sickness? And on, and on, and on.
SO. MANY. QUESTIONS.
Lastly, let's talk about study length. Pregnancy is really short period of time but BOY OH BOY, can the body change within that 9 months. Physiology is rapidly changing during pregnancy and postpartum. Hormones fluctuate, appetites change, weight changes- there are so many changes. So, if a research study looks at something like morning sickness for THREE weeks of a total pregnancy, how accurate is it likely to be? We know that morning sickness tends to be bad in the first trimester, decreasing in the second and then can come back in the third trimester (generally, however, it can occur in a number of variations or ALLLL pregnancy long). What if the research is conducted during the last week of a bunch of women's first trimester, and they are all just experience a "normal" weaning of morning sickness. Not likely, but what if? Or, what if they are at all DIFFERENT stages of pregnancy- is it really good information because their hormone levels are likely to vary. OR, what if these researches decided to test a bunch of women experiencing morning sickness in the 3rd trimester- when we KNOW energy levels and movement are already impaired- and they find exercise does nothing for morning sickness... is it legit? Did they do their due diligence in designing a research study that shows the full picture?
WHAT I'M SAYING is that we have to think critically and ask questions. Using research to hide or to only prove our point is chicken shit. Not looking at the other side, refusing to ask questions, ignoring research faults and bias only sets us up for disappointment later (unless we just want to keep our head in the sand).
As a professional, we should aim to give our clients the best information available even if it goes against a strongly held belief we once had. When I see other professionals take a singular research article and use it to make a point to sell a program it gives me a lot of pause. I usually lose my faith in them and stop trusting them.
Research is a TOOL; and we need to use it as such. Apply the principles you've learned and see if they work for the individual at hand. If they don't it doesn't mean that anyone is wrong, it just means you need to apply another tool.