Exercise

When it comes to exercise, I’ll give you the general picture first, then drill down into the details of what I found in the research. Finally, I’ll share my own conclusions about what this means about exercise for supporting egg quality and fertility. Jump to the end of this lesson if you just want my concluding recommendations.  

In general, exercise is good for us on so many levels. Our bodies are made to be moving, not sedentary. All systems function better when we are more active. People who are more active generally live longer and have less health problems. Healing often happens faster when people can be more active. There are many conditions, such as recovering from c-section, where doctors used to recommend minimal activity, but are now finding that more activity sooner actually leads to faster healing. Regular exercise can also be helpful for improving sleep and for reducing depression and anxiety.

The research on exercise and fertility is kind of sparse. Most of the studies I read concluded, “much more research is needed.” But the general take home message across all the studies seems to be stay active but don’t overdo it. I’ll expand on that more later. 

Research on exercise and mitochondria

The research on exercise and mitochondrial functioning is quite encouraging as there is evidence that exercise has a measurable positive effect on mitochondria, especially as we get older. Remember, our pathway to improving egg quality is largely via improving mitochondrial functioning. So anything that helps mitochondria might also help egg quality. This exercise-mitochondria research is quite new. I’ll delve into the three studies I found that have pretty exciting implications.  

Study #1

Enhanced Protein Translation Underlies Improved Metabolic and Physical Adaptations to Different Exercise Training Modes in Young and Old Humans

In this study published in 2017, researchers at the Mayo Clinic delved into an investigation of the mechanisms by which exercise might slow the cellular impact of aging. They looked at the impact on a cellular level of different kinds of training programs for two different age groups. They tested muscle tissue in participants 72 hours following the last exercise session at the end of 12 weeks of training.  

They compared mitochondrial capacity following three different training protocols:

1. High intensity interval training consisted of 12 weeks of cycling 4 times per week (four minutes, four times at high intensity) plus 45 minutes of treadmill walking twice per week.  
2. strength training (4 times per week) 
3. a combination of strength training (4 times per week) plus moderate intensity aerobic training (30 minutes cycling, 5 times per week) . 

The greatest positive impact on mitochondrial function indicators was in the high-intensity training group.  Among those doing high-intensity interval training, the younger group (age 18-30) showed a 49% increase in mitochondrial capacity, while the older group (age 65-80) showed a 65% increase in mitochondrial capacity. So the older group showed even more improvement, perhaps because their mitochondrial functioning was lower to begin with and had more potential for improvement.

The first thing that really stands out to me here is that they were actually able to see a measurable connection between exercise and mitochondrial function. The level of detail discussed in the original article might make you go cross-eyed, and you can really go down a rabbit hole trying to make sense of it all. But there are a lots of articles written about this study for the lay person, like this one from Medical News Today. I’ll pull two highlights from this article which I believe are relevant for our purposes.

The author writes:

If exercise can restore or minimize the deterioration of ribosomes and mitochondria in muscle cells, there is a good chance that it does the same in other tissues.

I would agree with this general stance. While mitochondria in skeletal muscle tissues are not the same thing as mitochondria in the egg cell, it’s not too far of a stretch to think that if exercise benefits mitochondria in one part of the body it might also benefit mitochondria elsewhere.

The author continues:

Dr. Nair and his team plan to extend their deep dive into the cellular benefits of exercise in other tissue types. In the future, these findings could potentially be used to target specific pathways and reduce the impact of aging. In time, perhaps these positive changes could be triggered artificially, but as Dr. Nair says: "There are substantial basic science data to support the idea that exercise is critically important to prevent or delay aging. There's no substitute for that." 

What the researchers and everyone who wrote articles about the research seemed most excited about what that high-intensity interval training appeared to be the best form of exercise for slowing the aging process. Part of what everyone is excited about is the prospect that these benefits can be seen with a workout that takes relatively little time and which some people will find more engaging compared to the standard 30-plus minutes of cardio workout. (Oddly, no one seems to mention that this protocol actually also included twice a week 45-minutes low intensity cardio.)  

As I continued searching for research on mitochondria and exercise, I came across two more very recent studies, which also looked the impact of high-intensity interval training on mitochondrial functioning.

Study #2

Acute HIIE elicits similar changes in human skeletal muscle mitochondrial H2O2release, respiration, and cell signaling as endurance exercise even with less work.

Original article abstract

Discussion of this study in Health Spectator

Discussion of this study in Healthline

This study, published in November 2018, involved eight “recreationally active” men and women (average age 24). Subjects had muscle biopsies taken before and after workouts. Results were analyzed from data from three different cycling workout sessions: (1) 30 minutes cycling at 50% effort (2) Five 4-minute high-intensity intervals at 75% effort, separated by one minute of rest, (3) Four 30-second sprint intervals with 4.5 minutes recover in between sprints.

All categories of workouts yielded similar mitochondrial functioning benefits. The striking result here is that four 30-second sprints might yield the same anti-aging benefits as 30 minutes of exercise.  

This is a very small study, with only 8 subjects, so care should be taken interpreting these findings. However I find it very promising that, again, mitochondrial benefits can be seen from exercise, and these benefits can be seen with relatively short exercise sessions.

While many of the discussions of this study are calling the HIIT workout “2 minutes of exercise,” we are actually looking at 30 minute intervals separated by 4.5 minutes of rested, repeated 4 times. So while the time of exertion is 2 minutes, the workout time is actually 20 minutes…and if you add in time to warm up and cool down, you’re looking at a 30 minute workout time.  

Study #3

High-intensity interval training enhances mitochondrial bioenergetics of platelets in patients with heart failure

Hot off the press! This study was just published (January 2019). 34 patients recovering from heart failure engaged in a 12-week program of high-intensity interval training (HIIT). 

The workout consisted of four 3-minute intervals of high intensity cycling with 3-minute intervals of low intensity cycling in between (starting with a three minute warm up and ending with a 3 minute cool down). This 30 minute workout was done three times per week for 12 weeks.  

They showed greater improvements in mitochondrial functioning compared to patients who were receiving general heath care (GHC). (Unfortunately there’s not description of what exercise was involved in “general health care”.

The graph below shows differences between the two groups on one of the measures of mitochondrial functioning. The light bars represent levels before the training period and the dark bars represent levels after 12 weeks of training. You can see the HIIT group showed improvements whereas the GHC group did not.

Summing up the mitochondria-exercise research

There are two main takeaways I’m gleaning from all these mitochondria-exercise studies.

Takeaway #1

There is strong evidence to suggest that exercise can improve mitochondrial functioning and this has ramifications for the aging process, which to me suggests potential for improving egg quality through exercise.  

I came across an article that delves deeply into these notions of how exercise impacts aging. The details in this article are way beyond me, but I find this part of the closing statements to be worthwhile as it further supports the notion that exercise has age-ameliorating effects on a cellular level:  

In conclusion, the connection between mtDNA and aerobic exercise has important implications for aging because it supports the notion of a relation between mitochondrial function and spontaneous physical activity; that is, endurance training increases mitochondrial function, stimulates spontaneous physical activity, and is a viable approach to interrupt the vicious cycle of aging. 

To me, that conclusion is pretty stunning, and it’s enough to get me up off my lazy butt and work toward integrating regular activity into my daily life for general longevity. And in terms of fertility, it is convincing me that exercise can very likely play a role in improving egg quality.

Takeaway #2

High-intensity interval training (HIIT) has real potential for boosting mitochondrial functioning and might be even more effective than longer workouts.  

Given that the research in this area is very new and there are only a handful of relatively small studies, I wouldn’t go as far as saying HIIT is “the best” kind of workout for mitochondria or other health benefits, but there’s evidence that it may be as effective and possibly even more effective than other workouts in some respects.

You might be wondering, what is HIIT all about exactly? I wondered this too, and here’s what I’ve learned...  

High-Intensity Interval Training (HIIT)

HIIT is a broad category for any exercise that involves short bursts of physical effort followed by brief recovery time, with this cycle repeated multiple times (usually 4 to 6 repetitions). The length of the intervals and the rest times can vary. A high-intensity interval could range from 3 seconds to 5 minutes. Short intervals are usually paired with short recovery times, unless the interval is a super high-intensity sprint in which a longer recovery time (like 5 minutes) might be used so that max energy is available for the next sprint. The total length of the typical HIIT workout will range from 10 to 30 minutes.

The actual exercise being done could include anything that’s physically demanding. It could be standard exercises like running, cycling or swimming. For those who are less fit, it could involve walking briskly up a hill or walking up stairs. It’s a matter of raising the exertion level to something close to your maximum output (70% or greater). 

How often can you do this? Most recommendations I read were to do it 2-3 times per week; or less for athletes who are doing other heavy training (which should probably not be anyone optimizing for fertility). Anything more than this could lead to over-training.

I liked the details in this review of HIIT, explaining the range of possibilities for structuring the workouts. It’s intended for athletes, but it’s consistent with the information I came across for non-athletes as well.  

The benefits of HIIT go beyond just the mitochondrial support. This article in Healthline gives an excellent rundown of benefits of HIIT with links to all the research articles cited. I recommend reading through the article if you're interested in the details, but here’s the quick list of benefits listed in this article:  

1. HIIT can burn a lot of calories in a short amount of time. It may help you burn more calories than traditional exercise, or burn the same amount of calories in a shorter amount of time
2. Your metabolic rate is higher for hours after exercise. This results in additional calories being burned even after you have finished exercising.
3. It can help you lose fat. In particular it can be effective at removing visceral fat (around your internal organs) which is a important for long-term health. 
4. You might gain muscle using HIIT. While not as much muscle gain would be expected as from weight training, whatever muscles are used in the HIIT exercise are likely to show increase in mas.
5. HIIT can improve oxygen consumption. It can improve oxygen consumption as much as traditional endurance training, even if you only exercise about half as long.
6. It can reduce heart rate and blood pressure. This has been found primarily for those who are overweight or have high blood pressure.
7. Blood sugar can be reduced by HIIT. Reduction in insulin resistance and improvements blood sugar levels has been found for both healthy and diabetic individuals.

HIIT for weight reduction

For those who are aiming to lose extra weight, HIIT can be an effective fat burning approach. This article, published in the Journal of Obesity in 2011, reviewed multiple studies looking at the impact of HIIT on fat loss and concluded that the indications are promising for these relatively short workouts to be effective for both losing fat and improving insulin sensitivity.  

One study published in 2008 compared HIIT to steady-state exercise and a control group (instructed to do what they normally do). Subjects were 45 young women (average age 20) randomly assigned to the three groups. (Note: in this study they use the acronym HIIE for HIIT.)

The HIIT workout consisted of 8 seconds of sprint cycling alternating with 12 seconds of slow pedaling, repeated for up to 20 minutes, with a 5 minute warmup and 5 minute cool down. The steady state workout consisted of 20 minutes of moderate intensity cycling, with 5 minutes warm up and 5 minutes cool down. Workouts were doing three times per week for 15 weeks.  

Both groups showed improvements in aerobic fitness. The HIIE group showed average weight loss of 5 pounds compared to an average weight gain of about 1 pound in the steady state exercise group. (See figure below.) When they reanalyzed the HIIE results removing subjects who were lower weight to begin with (average BMI 21.1), they found an average weight loss of 8 pounds. They also found benefits for the HIIE group in terms of fasting insulin and abdominal fat that were significantly better than for the steady-state exercise group.

They conclude that 20 minutes of HIIT may be more effective than 40 minutes of steady exercise for reducing fat and lowering insulin resistance.

While weight reduction is not advised for those who are trying to conceive who are normal weight, most research suggests that weight loss can be helpful for fertility for those who are overweight or obese. I'll discuss this issue more later.

One doctor’s take on HIIT

I came across some YouTube videos by Dr. Fort Brewer who specializes in preventive medical care.  

• HIIT: How to Grow New Mitochondria
• HIIT for Baby Boomers? Why? How? I’m too old and fat! Nope.

He’s a big fan of HIIT for general health for older adults and particularly for those recovering conditions such as from heart disease. I found it interesting to hear him talk about HIIT from his perspective, applying it to the “baby boomer” generation and explaining how to adapt HIIT to all levels of physical ability. His videos are kind of slow moving, so I’ll highlight some of the details I thought were useful.

• When you’re doing HIIT intervals, your pulse should be at 130-150 or higher. It’s hard to measure your pulse rate while sprinting so her prefers to use a general indicator of being out of breath to a degree that you are panting, unable to carry on conversation.  
• He recommends a sequence of 45 seconds high intensity alternating with 30 seconds rest.  
• He suggests five minutes of warm-up, 10 intervals, then 5 minutes cool down.  
• He recommends doing this 2-3 times per week, but not more, to avoid overtraining.  
• He suggests that people who are less fit do intervals walking up hills, walking up stairs, using a treadmill or elliptical machine or walking with a weight vest.  
• He points out that some paraplegic individuals do interval training with a hand cycling machine, so he figures most of us are plenty able to do some kind of HIIT workout. 

My thoughts on HIIT

I personally like the idea of a quick and intense workout. It suits my natural style, so I’m pretty thrilled to learn about HIIT and work it into my workout regimen for general health benefits.

Here are some of my thoughts as you consider this as a possibility for your program:

• Be careful not to lose weight if you are not overweight. You might need to up your caloric intake if you’re normal weight and prone to losing weight easily.
• If you think you would benefit from losing weight, this looks like a good workout option…and may be more effective than long cardio workouts.
• Don’t do this more than 3 times per week.
• I think this could be an effective part of an egg nurturing program due to the potential for boosting mitochondrial functioning.  
• I’m unsure about using this kind of intense workout while TTC, and I will elaborate on this in the next section.
• As always, listen to your body as an indicator of whether this kind of workout suits you.  

Fertility-specific research

Unfortunately, there is a real lack of good research studies on the impact of exercise on fertility. It’s well-established that extreme exercise throws off hormones, potentially interfering with ovulation. This is commonly seen among professional athletes or others who train very rigorously. But as far as exercise at mild to moderate levels, there’s much to be learned. Let’s take a look at the current research.

A Review of ovulation-exercise literature

A recent review (2017) of the research literature looked at the impact of exercise on ovulation. Among four cohort studies (in a cohort study, you look at group patterns without assigning any test interventions to participants) extremely heavy exercise (>60 minutes per day) was associated with ovulations problems, whereas vigorous exercise (30-60 minutes per day) corresponded with lower incidence of ovulation problems.  

Within that same review, they also looked at three intervention studies investigating the impact of vigorous exercise on healthy women. One of those three studies found that vigorous exercise had a negative impact on ovulation, the other two did not. Seven studies looking at women with PCOS found that exercise can help ovulation to resume.

The conclusion I take from this review is that extreme exercise can impact hormones in a way that interferes with ovulation. In some cases exercise helps restore ovulation. The amount and type of exercise that is most helpful is unclear.

Danish Cohort Study

A Danish cohort study published in 2012 looked at physical activity patterns of 3,628 women aged 18-40 (mean age 28) who were planning to get pregnant. Participants filled out surveys reporting how many hours per week they did “vigorous physical activity” (for example running, fast cycling, aerobics, gymnastics, or swimming) and how many hour per week they did “moderate physical activity” (for example brisk walking, leisurely cycling, golfing, or gardening). They were followed for 12 months to see how long it took them to get pregnant. Length of time to get pregnant was used as an indicator of relative fertility.

Here are some of the notable results:

• Among women with BMI <25 (underweight or normal weight), those who reported any level of vigorous physical activity above “none” (even as low as <1 hour per week) on average took longer to get pregnant than those who reported no vigorous activity. This effect still was found when they removed underweight women from the analysis (BMI<18.5)
• For those who were overweight (BMI >25, for example 160 lbs at 5’6” is BMI 25.8), moderate and vigorous activity was correlated with shorter times to pregnancy.
• The best fertility (shortest time to pregnancy) was found for those who reported >5 hrs/week of moderate activity and no vigorous activity.

I want to point out that vigorous physical activity is defined as what most of us would consider regular exercise (running, aerobics, swimming); whereas moderate activity would probably be considered by most to be pretty light exercise (brisk walking, gardening, golfing, leisurely cycling).  

What is surprising to me, was that increased time to get pregnant was seen with any level of vigorous activity. See the graph below. The "Fecundability Ratio" is some measure of how long it took a subject to get pregnant. The descending bold line indicates how with greater hours of vigorous activity, the length of time to get pregnant increased as compared to those who reported not exercising. My best guess is that exercise can create a competition for energy resources that may lead the body to delay getting pregnant.  

It was also interesting for me to see that getting more than five hours per week of relatively leisurely exercise seemed to correspond with the best outcomes (in terms of time to pregnancy).  

There are many limitations to this study, so it’s important to keep the findings in context. First, because it is a “cohort study,” you can’t conclude that A caused B. All we know is that these things occurred together. Also, none of these data are from women over age 40. We also don’t know how about the participants’ activity levels while they were trying to get pregnant; activity data were collected beforehand.  

With all these limitations in mind, the impressions that I draw from looking at this data are as follows:

1. The energy that is involved in moderate exercise (what they are calling “vigorous physical activity”) MIGHT divert some resources away from getting pregnant.
2. For those who are overweight, the fertility benefits of exercising at any intensity probably outweigh any of the negative effects.
3. Maintaining frequent physically active through light exercise (>5 hrs/week of “moderate physical activity”) is likely beneficial to getting pregnant.

The picture that’s forming for me is that the most fertile state (the most ready to get pregnant) is one in which the body is frequently active (getting good circulation and movement) but not taxed by the stress of physically demanding exercise.  

Norway Cohort Study

Let’s look at another cohort study, published in 2009, that investigated data collected from 3,887 women in Norway in the 1980s and 1990s. Read the original article here. Read an excellent summary of the article here.

Rating their exercise frequency as “never”, “less than once a week”, “2-3 times a week” and “almost every day”, those who exercised “almost every day” were 3.2 times more likely to not get pregnant in the following year compared to those who reported never exercising. 

Exercise intensity was rated as “take it easy” “lose breath,” and “to exhaustion”. Those who reported exercising “to exhaustion” were 2.3 times more likely to not be pregnant in the following year compared with those in the “take it easy” category.

(Differences were not significant for lesser levels of frequency and intensity.)

The duration of exercise was reported as <15 minutes, 15-30 minutes, 30-60 minutes and 60+ minutes. The highest likelihood of pregnancy within a year was seen for those in the 15-30 minutes duration.  

My reactions to this study:

• I was a little surprised that exercising “never” seemed to fair so well.
• I would really like to see whether those in the “almost every day” frequency were also in the “to exhaustion” intensity.  
• A duration of 15-30 minutes of non-intense exercise may be where the sweet spot lies.  

I like this closing comment in the research report (second to last paragraph of the discussion section):  

Although it cannot be concluded from this study, it seems likely that fertility may be positively affected by PA (physical activity) up to a certain level after which the energy requirements of the activity outweigh the positive effects, resulting in infertility. It is also possible that this threshold level applies merely at an individual level, perhaps in combination with energy availability, and cannot be identified at the population level.

Let’s look at a long excerpt from another summary of this research study, published in Science Daily:  

Scientists have a theory that high levels of physical activity are so energy intensive that the body actually experiences short periods of energy deficiency, where there simply is not enough energy to maintain all the necessary hormonal mechanisms that enable fertilization.

On the other hand, previous research shows that moderate physical activity gives women better insulin function and an improved hormonal profile -- and thus better conditions for fertility -- than total inactivity, particularly in overweight people.

But Gudmundsdottir says that women who want to become pregnant shouldn't give up all physical activity. "We believe it is likely that physical activity at a very high or very low level has a negative effect on fertility, while moderate activity is beneficial," she says.

But as far as identifying how much is "just right," the researcher is careful. "An individual's energy metabolism is a very important factor in this context. The threshold can be very individual," Gudmundsdottir says. She also recommends that physically active women be particularly aware of their menstrual cycles. "A long cycle or no menstruation at all are danger signals," she says.

All these conclusions sound very reasonable to me.

Making sense of it all...

These recommendations really support the approach I ultimately recommend of listening carefully to your own body. Recognize that creating new life requires a lot of dedicated energy from your body. Look for ways to support this energy, finding methods to build it while also being careful not to overly deplete it. Individual needs are going to vary, so there’s no correct formula that works equally for everyone. It’s about finding the right balance for your body.

All these studies and recommendations are centered around what is most likely to lead to pregnancy for women around the average age of 28.  

But what about for older women who are also contending with the age factor, and needing to optimize mitochondrial function? Do we draw the same conclusions when our purpose is optimizing egg quality?

Recall the Mayo Clinic researchers concluded that high-intensity interval training was best for reducing the cellular impact of aging on the mitochondria. But high-intensity interval training might put us in the category of exercising “to exhaustion”

OMG! We have opposite recommendations here! Exercise your butt off to boost your mitochondria, but chill out to enhance your ability to get pregnant. 

Although, if you’re overweight you’re in luck because vigorous exercise may be just fine, so you can go ahead with interval training.  

But what if you are normal weight? What the heck?

Okay, remain calm. I don’t want anyone’s head to explode here.

Let’s not get carried away with the research details. The researchers are just starting out in exploring these matters so it’s important to look at all this with broader brush strokes. Let’s look across all the evidence and see what makes sense.

What are other fertility specialists saying?

Before I draw together my conclusions about all of this as a whole, I’d like to point out what some of the seasoned fertility specialists are saying. 

This blog post by reproductive endocrinologist Dr. Barbara Osborn from Shady Grove Fertility provides a similar perspective to what we have covered here.  

At the end she concludes:  

In summary, we have very little data on which to state a link between exercise and fertility. From the available studies, however, it seems that moderate activity such as walking and leisurely cycling seems to make the most sense for women trying to conceive naturally or through fertility treatment.

Integrating the perspective of Traditional Chinese Medicine Chinese medicine with Western medicine, Dr. Jill Blakeaway, coauthor of the popular fertility book Making Babies, offers a blog post with recommendations for how to tailor your exercise program to where you are in your cycle while TTC.  Interesting suggestions are offered including really taking it easy physically during the second half of your cycle, after ovulation.

The state of the research

If all this information feels a little overwhelming, it’s not you—the field is just too undeveloped to give us strong clear direction. I appreciated the last paragraph of this commentary published in 2016, “Studying the Complex Relationships Between Physical Activity and Infertility.”

Although recommendations exist for physical activity during pregnancy, there are no clear guidelines on physical activity for women who are trying to conceive. Biological evidence supports the hypothesis that physical activity may affect infertility, since those who engage in vigorous physical activity may have an increased risk for infertility due to anovulation and possibly implantation failure. However, the relationship is likely complex, and studies with adequate statistical power are needed to explore potential moderators such as BMI and age.

Given the wide range of physical activity exposure measures, in combination with differing covariates and infertility outcomes used across studies, it is not surprising that firm conclusions about the influence of physical activity on infertility cannot be drawn at this time. However, given the benefits of physical activity to health, and that unexplained infertility remains of widespread concern globally, establishing the optimum type, duration, intensity, and frequency of physical activity for conception remains an important area for research.

So the takeaway message here is that “it’s complicated” and “we don’t know a whole lot,” but we’re pretty sure that one can encounter fertility problems from over-exercising.  

My Recommendations 

With the absence of more solid research, my approach is to apply what’s well known, and in the areas that are more vague, apply our best common sense and intuition. I’ll walk you through my thought process and you can draw your own conclusions about what makes sense for you.

When it comes to egg quality, we are looking at what might improve mitochondrial functioning. Exercise in general appears to be good for mitochondria. Breaking down the types of exercise, there’s growing support for high-intensity interval training. We don’t know how exactly this translates to mitochondrial function in egg cells, but I would guess that exercise, in general, can be helpful to mitochondria and egg quality. Maybe high-intensity training would give the eggs an extra boost, but that’s just a guess at this stage. I also assume that anything that is overly depleting of our energy is not good for mitochondria, so I would think that over-exercising would potentially lead to poorer egg quality.

When it comes to weight loss, we are not trying to get on the cover of a fitness magazine, so if you’ve got an extra 5 to 15 pounds, I recommend you just love your body the way it is. If you have more extra weight than that, you fertility might be enhanced by some weight loss. HIIT looks like a good option for reducing fat, but be sure not to do these workouts more than three times a week. For the most part more strenuous workouts have not been seen as a problem in the research, but these studies are not done on women over 40. I’m leaning toward not recommending intense workouts during TTC for women over 40 who are having trouble getting pregnant. It might be more important to conserve energy than to burn fat, but I’m sure there are a lot of individual difference and no one formula is best for everyone.  

When it comes to getting pregnant, it appears that keeping the intensity on the mild side but staying fairly active leads to the shortest time to pregnancy in younger women. Whatever leads to quicker pregnancy in younger women is probably generally favorable to hormonal balance and overall fertility at older ages as well. So moderate to intense exercise might not be the best idea while trying to get pregnant. Researchers have also noted that the negative impact of intense exercise on fertility seems to reverse once that intensity is reduced. 

So all this is leading me toward a two-phase exercise recommendation…  

Phase 1 - During an egg nurturing phase if you are not actively TTC, vigorous exercise might be worth incorporating. But still keep it in a range that’s not exhausting and depleting, probably keeping it within 30 minutes if it’s more than mild intensity.  High-intensity interval training (short bursts of more intense exertion) might be worth incorporating into your workouts.

Phase 2 - Once you transition to actively TTC, dial back the intensity on your exercise to something pretty easy-going but still active. Limit exercise to 15-30 minutes in a typical exercise session (if you would typically do more). Add in enough physical activity to bring your total time spent moving your body to over 5 hours per week. If you’re in TTC mode and you’re having trouble getting pregnant, ease back on exercise intensity and consider doing only mild intensity for a few cycles. Consider keeping exercise extra mellow during the second half any cycle in which you think you might get pregnant. 

What I would recommend at all times, whether TTC or egg nurturing:

1. Aim for a good amount of mild physical activity (>5 hours per week). Consider brisk walking, leisurely cycling, gentle yoga, gardening, vacuuming or mopping your floors, mowing the lawn. 
2. Avoid pushing yourself to the point of exhaustion.  
3. Incorporate rest days.
4. Really listen to your body to determine what constitutes an intensity that is depleting versus one that is activating and invigorating.  
5. Avoid hot yoga and other strenuous workout classes.
6. Avoid training and competitive events that push you to your limits.  
7. Explore a range of gentle, mild physical activity: Tai chi, gentle yoga, easy dancing.  
8. Incorporate stretching and strengthening into your program. These are important for your overall well-being and long-term physical health.
9. Keep your body moving, your blood circulating, your energy flowing.

A few words about yoga…

Yoga can mean a lot of things to a lot of people. I will be adding a section about yoga at some point. But know that there are many approaches to yoga and you’ll want to look for a form that fits your needs.

There are different philosophies behind each style and also varying levels of intensity among styles.  

For the purposes of enhancing fertility, I would recommend more gentle, restorative, and meditative approaches. You might find class titles like gentle yoga, restorative yoga, yin yoga, and yoga nidra.  

More intense styles would include power yoga, some vinyassa yoga, anything at a heated yoga studio such as Bikram or Core Power. I strongly caution against these, but of course it’s up to you to listen to your body to determine what’s going to be most supportive of your fertility.

If you feel exhausted by the experience or if the class is causing you pain or strain, this might not be the best time to pursue this style of yoga.  

Sample exercise programs

Let’s preface this with, I’m not a fitness trainer! I’m just basing these ideas on what I’ve read in the research I’ve described above. I’m going to put down my ideas of what a reasonable program might look like, but please listen to your own body, consult with your own practitioners or fitness trainers to decide what is right for you. I’m offering this suggestions just to help give some concrete ideas of what it might look like to incorporate the huge amount of information I’ve just shared in this lesson.

Egg Nurturing sample plan:  

• 2-3 days HIIT (4 short sprints alternating with resting or light movement). Always incorporate warm up and cool down including stretching.
• 2 days strength training and stretching
• 2 days yoga or tai chi
• 1 day super mellow
• Most days, some kind of light physical activity…housework, gardening, walking.  

TTC sample plan:

• 2-3 days gentle yoga, stretching, dancing or tai chi
• 2-3 days walking, household cleaning, gardening
• 2 days 15-30 minutes light cardio plus strength training
• keep everything light post-ovulation

These are just some ideas to play with. I would love to see others' ideas in the comments below.

Closing Thoughts

I know there’s a LOT of information in this section, so I want to boil it down even more to just a few key points:

• Stay active – don’t be a couch potato
• Conserve your energy – be cautious about over-exercising
• Look for the joy in moving your body
• Aim to keep your body agile and your blood circulating through mild daily physical activity
• Listen to your body to determine the sweet spot for staying energized but not depleted.

Congratulations on making it to the end of a whole huge amount of information. Take time to digest it, let it sink in. Don't sweat the details. Aim for a lifestyle of joyful replenishing physical activity.