The Benefits od Resistance Training While Pregnant

I have trained close to 200 pregnant women over the last 17 years. I believed so strongly in the potential for women to optimize their health and wellness during pregnancy that I left a promising job training athletes to open the first fitness studio in Montreal to specialize in prenatal and postnatal fitness. This was back in 2008 when there was little to no research on safety or program design. It was an uphill battle against the norms of rest or low exertion but things have come a long way in the last two decades.

Data almost always counts more than ‘anecdata’ and so I will start with a bit of a study review before I talk about my personal experience. Data is a tricky thing to turn into real life training protocols so I do want to include both the science along with my observations. So first let’s look at what the nerds say…

* you can scroll down to the conclusion to get the gist of things but the “ my observations from the studio” section is worth the 2 minute read.

In a 2024 research review looking at the benefits and safety of weight training with pregnant women, the authors concluded that resistance training is “safe, beneficial and effective form of exercise for pregnant women to increase fitness and improve pregnancy outcomes…” Noting that the addition of aerobic exercise could enhance the benefit as well…

Resistance training, alone or together with aerobic exercise, can improve maternal symptoms of pregnancy, mediate the effects of gestational diabetes and obesity on maternal and fetal health, and improve labor and delivery outcomes for both mother and fetus. Resistance training during pregnancy can also improve fetal development and infant health from childhood well into adulthood.

We need more research to have strong quantitative conclusions on these benefits but as you will see the vast majority of research points towards advantages to both mother and baby.

A small control trial from 2017 looking at the effects of regular exercise on cholesterol and triglyceride levels during pregnancy found some interesting results. 50 Latina women were split into two groups, one that did three 60 minute workouts each week which comprised of both cardiovascular and resistance training. The other group maintained their regular activity level. What they found:

  • significantly lower levels of LDL and triglycerides in the active group.
  • less delivery issues (moderate postpartum hemorrhage) in the active group
  • fewer complications in newborns in the active group – less issues with blood oxygen levels (cyanosis) and less respiratory distress.

Obviously we need a larger trial with a more expansive demographic to make any strong conclusions but the results do match other small control trials and epidemiological data.

While I am focusing on strength training here there is some interesting research looking at aerobic fitness level and labor duration. This observational study used maximum oxygen uptake levels to measure aerobic capacity in women who had spontaneous deliveries. They saw that higher aerobic fitness was correlated with shorter labor times. Though there are a number of factors that could impede the benefits of aerobic fitness on labor duration this is definitely something many of my clients would want to know about. No one wants a longer than necessary delivery and so I try and include one to two endurance workouts each week (depending on how often the person is training). These are focused on maintaining or improving aerobic capacity as blood volume increases. Not V02 max training, just simple aerobic/endurance workouts.

2006 literature review on exercise in the prevention of maternal-fetal disease also had promising findings –

  • women who were the most active have the lowest incidence of gestational diabetes.
  • prevention of gestational diabetes lowers the probability of type 2 diabetes in both mother and child.
  • women who exercise have a lower incidence of pre-eclampsia.
  • 4 mechanisms have been observed that may explain the above benefit: 1 – exercise in early pregnancy enhances placental growth and blood flow, 2 – exercise reduces oxidative stress, 3 – exercise reduces inflammation, 4 – exercise appears to correct disease related endothelial
  • Exercise may combat reproductive issues due to obesity
the pathophysiology of pre-eclampsia

Obesity and pregnancy

Women who are obese prior to pregnancy have increased risk of polycystic ovarian syndrome (PCOS), menstrual irregularity and infertility. Obesity may also be responsible for the increased risk of spontaneous abortion rates in women with PCOS. It is also found that fertility treatments are less effective for women who are significantly overweight,

During pregnancy women who are overweight or obese have an increasing (as weight goes up) risk of pre-eclampsia and gestational diabetes. overweight women tend to give birth to larger babies even when pre-eclampsia and gestational diabetes are not a factor. There is an increased risk of neonatal intensive care, caesarian section and instrument delivery.

Interestingly, a 2009 study suggests that resistance training while pregnant, even for moms-to-be who were overweight or obese during pregnancy reduced the incidence of high birth weights of the baby. The mothers weight did not have to change significantly for the effects of resistance training to benefit the baby.

Another study showed that resistance training performed 3-5 times per week showed correlations with increased fetal length and more lean body mass than the control group. In some research looking to see if there were any long term benefits for children who’s mothers engaged in vigorous exercise during pregnancy they found that these children had heightened attentiveness and discipline and were cognitively more advanced by age 5 than the control group. They concluded that increased blood volume, cardiac output, placental functioning and nutrient delivery were likely behind the benefits

As mentioned above this is new research, predominantly small studies but the results are significant and the mechanisms seem to line up with the results so we will have to keep our eyes on the field and see if repeated studies have similar findings.

Easier Labour

Exercise has been shown to reduce the incidence of a number of complications during labour, with resistance training having a significant benefit. Several studies (123456) have described decreased labour times, shorter hospitalization, and a reduced incidence of C-section, abdominal and vaginal operative deliveries.

In the last 17 years of training pregnant women I can vouch that it appears that the women who have trained consistently and vigorously during their pregnancy seem to have easier deliveries and postnatal recovery times in general. This isn’t some kind of guarantee , there are many factors at play. One of them seems to be duration of training. The clients of mine who have been with me prior to pregnancy seem to be easier off during labour. But again not every time. Age plays a role, the position of the baby plays a role, umbilical issues play a role, etc.

My observation from our studio

And now lets see what this nerd says…

The majority of studies looking at preventing or managing prenatal weight have used a mix of diet and aerobic exercise. But we know that exercise only has a minimal effect on weight management. The things that move the needle the most is calorie restriction and non exercise related activity. Exercise absolutely counts for energy expenditure but I think what we will see as the research continues is that a mix of both aerobic and resistance training is necessary or optimal while everyday activities outside of the workouts count much more.

quick side note –

A well designed strength program can assisst those who may have trouble moving around throughout the day. Asking someone to just be more active who has not been so for some time or struggles with joint pain or stability needs specific help to get there.

Weight management is only one aspect of the health benefits during pregnancy. If Aerobic and resistance training are going to both lead to minimal weight shifts we then need to determine what other benefits arise from both. That said, my clients who optimize their diet during pregnancy have not only had enjoyable pregnancies but they have improved their own health markers and weight profile. I want to emphasize that losing weight during pregnancy by managing calories is a serious endeavour. You need to make sure you are eating enough. This is easily accomplished with tracking but you need to be consistent. This isn’t the time to mess around with a low calorie diet all willy nilly. I do not recommend this. Just remember that adding moderate to vigorous exercise to your life will extend benefits to you and the baby regardless of weight loss.

A better approach would be to try and manage weight as soon as you start trying to get pregnant or even better – about a year before you think you might want to start. Not everyone knows that far ahead of time but if you do, it’s something to consider.

As mentioned above, there are studies that correlate decreased labor times and developmental advantages with aerobic fitness so we should make sure this is part of an exercise regimen. I don’t think anyone, pregnant or not, male or female, should choose aerobic over resistance training or vice versa. Both are equally important for health and longevity. But from my experience the benefits that strength and stability training have for overall pregnancy satisfaction, prevention of pelvic floor and back pain which leads to better sleep and ability to recover postpartum is what makes it a priority for my clients. If time is a factor I would prioritize resistance training or if there is a personal preference towards strength training I am happy to indulge and focus on the many benefits it has. If someone prefers aerobic fitness then that also works. Always make the most time for the thing that will keep the person happy and engaged…and then just slip in some weighted lunges…oops!

Hip mobility and shoulder/postural strength and stability are two major factors you won’t find in the research. The posture changes quickly as the belly expands outwards and this can have delterious effects both during pregnancy and afterwards while feeding. Mitigating these issues is a major focus in our studio and specific resistance training is what we use to do so.

There are a number of other things we tend to address depending on the individual, all of which are not included as specific benefits cited through research but can fall under the improved mood and sleep categories. This is because the increased strength and fitness lowers discomfort and upregulates hormones that allow for better moods and sleep!

The studies do a great job in defining safety and measuring the short term benefits of blood markers and disease reduction during pregnancy and delivery. But they miss out on what women need right after delivery, which is a strong, agile and stable body. They also often need postnatal abdominal recovery. Though the science is out on whether you can prevent diastasis recti (the thinning of the abdominal wall) through exercise, this is something that I have witnessed in the studio. I am the first to admit that this is anecdotal and not science.

We don’t focus solely on abdominal strengthening, we also work on diaphragmatic breathing to make a mind body connection during relaxation phase. Doing these types of exercises during a workout is great but we have a system that we try and employ with our clients that helps them engage with activation and relaxation throughout the day. Again, this is not hard science. I have simply been trying to address an issue with some ideas that make sense on a biological level. We are trying to plug the gaps in awareness that may lead to a weakening or an overuse issue.

There is a case that academics occasionally miss the mark when compared to professional trainers. It’s true that lab settings are not the same as real life and we need to take this into consideration when employing results found in studies. It is also true that not all trainers are created equal but good ones that actually train people in person (not instagram online trainers) usually have long records of trial and error and have found what works. They also pay close attention to the research and recognize what is useful vs what is a tiny “significant” result in a study that makes no difference in the real world.

A well rounded exercise program will increase mobility, stability, endurance and strength – all of which carry over nicely into life as a new parent. Aerobic exercise has clear benefits and it should very much be part of the regimen. I think it is important to note that the people who come to me that prioritize running or cycling tend to have the worst overall physical assessments (other than cardiovascular ability). This is not universal but it is common. So if this sounds like you, I implore you to try and include more resistance training. Pregnancy is a great time to try and get good general fitness, it will make the time even more enjoyable and the benefits will be very clear when you are trying to soothe a baby for hours or reaching down low to pick up a floppy infant and yet again when you’re wrangling a toddler.

Conslusions

The research may still be growing but there are some real takeaways that are important for the public, for doctors and for trainers –

  • aerobic and strength exercise is not just safe but should be encouraged.
  • both can can help lower maternal cholesterol levels during pregnancy.
  • both have been seen in multiple studies to reduce labor duration.
  • both can reduce the incidence of gestational diabetes and pre-ecamplsia and the reduction of gestational diabetes carries over to lower risk in type 2 diabetes for both the mother and infant as they age.
  • strength training has been linked to better physical and cognitive development for the fetus that continue after birth up until the age of 5 (latest it has been followed up so far).
  • some studies suggest that women who strength train have lower risks of C-sections and other delivery complications.
  • mothers who exercise during pregnancy have babies born with less blood oxygen and respiratory issues.

There are very specific situations where exercise may be discouraged for pregnant women. Your doctors will let you know when you need to slow down or stop. But outside of extenuating circumstances the biggest takeaway here is that vigorous exercise is completely safe.

There are some small studies that suggest certain powerlifting movements are also safe. I still err on the side of caution when it comes to power training. While the exercises may be deemed safe for the ultra trained individual, I think introducing these movements shortly before or during pregnancy can be problematic. These exercises take a lot of coordination and body awareness. During pregnancy the body is changing at a more rapid rate than at any part of your life and subtle differences in center of gravity, joint mobility and breathing disturbances can affect peoples ability to perform explosive movements with precision. So this is out for me and honestly I think it is an unnecessary risk even for well trained powerlifters. It’s not so much about a risk to the baby or the pregnancy in general but more as a risk of injury to the mom. An injury can sideline you from all activity for the remainder of the pregnancy and then make being a new mom so much harder than it needs to be. You can take a 10-12 month break, its going to be fine.

If you or anyone you know needs some help designing a well rounded program that will optimize for many of the benefits listed above please fee free to contact me for help. We do online consultations as well as our in person training for those who live in the Montreal area.

Longevity Centred Fitness Classes

We have been providing science based programs for Montrealers for over 16 years. We have helped athletes improve performance, women optimize health during pregnancy, people overcome injury and thrive with physical disabilities and have helped hundreds of others go through their health and fitness goals.

Don’t believe the hype – How much muscle do you need for longevity.

You may have noticed the pendulum swinging with the new craze of huge protein consumption rates and big push to gain muscle mass. I came across one woman’s channel trying to convince every woman to bulk up – to go hard against the fear of it. Indeed I have had many women approach me over the past 2 decades for training and say that they don’t want to bulk up. And then you have loads of trainers, including myself that have for years tried to explain how hard it is to truly get bulky. But being aware that it’s difficult doesn’t mean you should or shouldn’t do it. It is not, though it would appear many would disagree with me, all good to get huge. There are consequences, amenorrhea being just one of them. But to get attention now, you have to sell the other end of the spectrum, now, instead of simply reassuring that bulkiness is not necessary and also very unlikely without massive changes and effort, we try and sell the bulk, be the bulk, Bulk Smash. Extremes sell but guess what, as always, the answer to most questions lies in the middle, close to our instincts and often less fun to talk about at a party.

Obesity and Pregnancy – the risks to the baby

You can be overweight and still be healthy. You can eat a diet where 80% of your nutrition comes from nutrient dense whole foods and the rest may be processed or ultra processed foods and you will probably still be in pretty good health. Especially if you are adding regular intense exercise and moderating stress and have good sleep hygiene. You can also live this way and have small tweaks in one of these factors and begin to develop health issues. But what often happens is that the slightly overweight person tips over into obesity range and inevitably, the health risks begin to accumulate with no real warning signs. At some point, the accumulation of fat stores throws things out of balance and creates a state of inflammation. This is not an overnight process and so it often goes overlooked for way too long. I am all for being comfortable with how you look but I am more interested in all of us as a society moving towards preventative medicine and using signals like obesity to look for red flags elsewhere is important.

-PROMOTION- Partnered Training Discount

For new clients that start any time in June or July 2024 each person in your pair or trio will have a discounted rate for 6 months of training!

As a precision training studio we shy away from large group classes. There are benefits to working out in groups, some people need the camaraderie in order to maintain commitment, it can be very motivating to workout with others.

We do detailed physical evaluations for every client and 100% of the time the client needs foundational programming and tailored exercises for imbalances and/or goals specific to the individual. This is relatively impossible to achieve in a group setting.

Partnered training seems to allow for the best of both worlds. We get the motivation and healthy competition from training with a partner as well as enough attention from the trainer to prepare and assist with individualized programs. Most of the time we ask clients to come with their own partner. A friend or family member to increases the chances of maintaining accountability- plus it is difficult for us to find other trainees who have the same availability as you may have. Different fitness level between the pair is usually fine. If one of you has a significant injury or a very specific goal that requires a lot of attention then we suggest training individually.

DISCOUNT RATE –

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Discount is running through July. New clients only and the rate will remain stable for 6 months.

Increasing VO2max – your best tool to live longer

vo2max

“Cardiorespiratory fitness is inversely associated with long-term mortality with no observed upper limit of benefit.” This conclusion comes from a 2018 study published in the journal Cardiology (1) measuring all cause mortality in 122,000 participants under a treadmill based cardiovascular test.

Segmented into groups of cardiovascular health as such – Low, below average, above average, high and elite we can see how shifting from one group to another changes your risk of all cause mortality. For example, if you improve your fitness from low to below average you decrease your risk of mortality by 50%. If you can manage to move from low to above average it will decrease by 60-70%. When comparing this improvement vs the benefits of quitting smoking or reversing diabetes, increasing your cardiovascular fitness actually has a greater impact on mortality risk. These are incredible results. No single action moves the needle more for increasing longevity than improving cardiovascular health.

Exercise protocols to reverse cardiovascular disease

As a follow up to the last article I wanted to provide some information on how to combat heart disease with exercise. There are a couple myths worth dispelling and some very good science on what methods work best for people who are at high risk for an event or who are coming out of hospital, post event

Cumulative Training

I am normally not super interested in what works for the average person. My career started with a succession of failures trying to apply the science of averages to individuals. If there is one thing you learn (hopefully early) as a health coach is that the most important research is the N of 1 kind. In other words, what works for the person in front of you. This still involves looking at all the prevailing research, it’s not just throwing ideas out all willy nilly but it inevitably requires trial and error. So you have to be humble in the process and clear in setting reasonable expectations.