Fitness and Nutrition in the First Trimester

Fitness and Nutrition in the First Trimester

As a trainer, I have trained many pregnant clients through their entire pregnancies, but I have never experienced the joys and challenges of pregnancy firsthand…until now.

Influenced by my knowledge of training others and now with my own firsthand experience, these are my thoughts on having a healthy and fit first trimester of pregnancy.

Depending on when you find out your pregnant your first trimester can be quite short but, in my case, we did IVF so I got to experience the whole 13 weeks of my first trimester (even though the first two weeks you are not even pregnant at all)

The first trimester comes with a lot of challenges: tender swollen breast, nausea with or without vomiting, increased urination, fatigue, food aversions, heartburn, constipation.  All these lovely first trimester symptoms can make living a healthy lifestyle a challenge.

Everybody’s first trimester is different, keep in mind my recommendations are based on what I experienced during my first trimester.


One of the important things to remember with first-trimester nutrition is that your calorie needs are no different than pre-pregnancy.  There is no necessary weight gain for this stage of pregnancy.  Therefore, your diet can stay exactly the same as before the little one made home in your body.

This is all good in theory but in reality, those pesky pregnancy symptoms can make keeping your pre-pregnancy diet a challenge.

For me, my two biggest symptoms in my first trimester were nausea and fatigue.  70% of all women experience nausea while only 50% will actually vomit, I was in that 20% that felt nauseous without vomiting.

I discovered that when I felt hungry my nausea got worse.  As long as I ate regularly, I could keep my nausea at bay.  On top of that, it was carbs that tended to soothe nausea better.  When I tried to eat fruits or vegetables when I felt nausea my symptoms would not dissipate, but the minute I had some crackers or bread my nausea would disappear immediately.

Before pregnancy, I would eat 2-3 meals with long fasts in-between.  In general, I never snacked.  Since I did not eat that often, this allowed my meals to be quite substantial which is how I prefer to eat.  I also rarely ate carbs, because they tended to not make me feel good and also very easily put weight on me.

My plan going into my first trimester was to keep my diet relatively the same, maybe a little healthier for the little babe, but very quickly I discovered that this was not going to be my reality.   My normal big meals plus all the carb snacking was proving to be too much food.

Since I had to eat more frequently, I need to make my meals substantially smaller, almost snack-sized.  I was essentially just snacking all day.  I tried tracking my food in MyFitnessPal to make sure I wasn’t undereating or overeating.  My goal was 1500 calories, which was the same as pre-pregnancy.  Tracking can also be useful to get over the pregnancy mindset of I can eat whatever I want.

Tracking didn’t always happen due to another one of my symptoms…fatigue which I will talk about later.


In the first trimester, your baby is very small, so your body hasn’t begun shifting to accommodate the growing baby.  Your physical body won’t prohibit any exercises you desire to do.  Although your body hasn’t changed much there are still some changes that will affect your workouts. The first challenge I had to overcome for working out during my pregnancy was the mental challenge that exercise could cause a miscarriage.  Although there is no research that indicates that exercise can cause miscarriage it is hard to overcome this thought especially if you have struggled with infertility as I did.   For me, it was better for my mental health to just take a break from exercise, besides walking, from the time of my embryo transfer to our first heart beast ultrasound at 7 weeks.  This made me feel better than having the anxiety surrounding my workouts and this little baby I so desperately wanted to stick.

Once I was mentally ready to resume workouts there were a couple of more challenges that came with my first-trimester workout routine.  Before pregnancy, my fitness routine consisted of a 5 am orange theory class every weekday morning and a spin class on the weekends.

My first challenge to keep up this routine was my fatigue.  It usually isn’t that difficult for me to wake up for my 5 am class but during that first trimester, it seemed impossible somedays.  Not only was waking up early difficult on the work breaks I mostly just wanted to nap.  My days consisted of working then napping then repeating.  Although it was challenging, I did manage to make it to 2-3 classes a week.

Even when I was at the classes there were some changes I noticed in my fitness ability.  For the most part, I did not notice any changes when I was lifting.  I was able to lift the same level of weights as I did before pregnancy.  The only time I felt different on the weight floor was doing something that elevated my heart rate, which I will explain later.

The biggest difference I noticed in my workout was during cardio.  Running was almost unbearable due to my sore and tender breasts.  Pre-pregnancy right before my period would start, I would sometime notice breast tenderness during my run, these sensations would usually dissipate after I ran for a couple of minutes and I wouldn’t notice it for the rest of my run.  During my first trimester, the discomfort in my breast during running was more intense and never ended.  Even after I stopped running, my breasts would continue to feel irritated for several minutes.  Due to this I mainly stopped running altogether and would just walk at an incline.

It was also a lot easier for me to get winded during cardio and faster-paced lifting exercises.  In your first trimester, this is due to the increasing progesterone in your body.  As your body adjusts to new hormone levels it becomes much easier to become winded.  It felt like exercising in high altitude, the minute you would start you would be out of breath.

Although there is no weight gain necessary in the first trimester, I ended up gaining 5lbs.  I think this was predominantly due to my increase in carb intake and my reduced fitness routine.  If you are like me and gained weight during your first trimester don’t freak out, it doesn’t mean that you are destined to gain 100lbs during this pregnancy.  The first trimester can be tricky, you just have to do the best you can to get through it the best way you can.  Any bad habits that snuck into your routine during your first trimester can be reversed when you are feeling much better in the second trimester.

It is important to keep in mind that everybody’s pregnancy is different, so the most important thing is to do what is right for you and your growing baby.  We are all the best parents for our little babies and ultimately know what is right for them, even in utero.

I am excited to be feeling better and moving into what I have been told is the honeymoon phase of my pregnancy, the second trimester.

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