Being active helps us to remain healthy and if we are healthy we are more likely to be able to have children. On the flip side a sedentary lifestyle has been shown to be seriously damaging to our health. For example, a massive study[1] of over one million adults carried out by the University of Cambridge and published in the prestigious journal The Lancet found that people in typical desk jobs that do not do much exercise are 59% more likely to die early than people in typical desk jobs that are physically active.

What can it help with?

How can it help?

Fitness is clearly important to our general health and well-being but does it impact our chances of success with IVF? Let’s have a look.

The research suggests that moderate levels of exercise are beneficial to female fertility. For example:

1. in a study[2] of 26,955 women a 7% improvement in fertility was seen with each hour per week of exercise
2. another study found that one hour’s exercise three times per week increased the chances of pregnancy by 83% for patients undergoing an ICSI cycle[3]
3. a study found that women undergoing IVF treatment who did moderate levels of exercise had implantation rates of 29.6% compared to 19.4% in women with low levels of exercise and live birth rates of 47.6% compared to 22.1%[4]
4. in a study[5] of 216 women obese participants who did the most physical activity had implantation rates and live birth rates that were 3 times the rate of the women who did the lowest levels of physical activity
5. a meta-analysis[6] found that women who exercised for at least two and a half hours per week were 96% more likely to become pregnant and 95% more likely to have a live birth

However, with exercise it seems that you can have too much of a good thing as far as fertility is concerned:

1. in a study of 2,232 women undergoing IVF those who exercised for more than 4 hours per week for a period of 1-9 years prior to a cycle were three times more likely to have the cycle cancelled, twice as likely to have implantation failure, twice as likely to suffer miscarriage and 40% less likely to have a live birth[7]
2. another study[8] of 346 women found that those that undertook vigorous exercise for more than 1 hour each day were between 1.9 and 6.2 times more likely to be infertile however those that did less than 1 hour per day of vigorous exercise were not at an increased risk
3. a Norwegian study[9] of over 77,000 people found that women who exercised at an extreme level of intensity and frequency – similar to that of elite athletes – had a 3 fold risk of infertility

As with women it seems that moderate levels of exercise are beneficial to male fertility:

1. a study[10] involving men attending a fertility clinic in Boston found that men who did 7 hours of moderate to vigorous exercise (broadly defined as any exercise except walking) per week had 43% higher sperm concentrations than those that did the least
2. another study[11] used men’s television watching habits as a measure of their levels of exercise and found a consistent relationship between the amount of television watched (and therefore the less exercise taken) and a lowering of sperm concentration. The group of men that watched the highest levels of television each week had sperm concentrations that were 44% less than those that watched the least

But, again, too much exercise appears to be bad for fertility:

1. in one study[12] a group of 286 men were assigned to do either 120 minutes of high intensity exercise 5 times per week for 60 weeks or 120 minutes of moderate intensity exercise 5 times per week for 60 weeks. The combination of exercise duration and intensity resulted in semen quality in the men in the high intensity group declining
2. another study[13] looked at the semen quality of a group of “physically active” men who exercised 3 times per week for 1 hour a time, a group of water polo players who exercised 5 times per week for 90 minutes per time and a group of Ironman triathletes who exercised 10 times per week for 120 minutes per session. The researchers found that sperm morphology declined from 15.2% in the physically active group to 9.7% in the water polo group and 4.7% in the triathlete group

What can we do?

Before undertaking any exercise programme you should speak to your doctor and get his go-ahead. Only once you have done this should you begin.

Clearly for both men and women there is a balance to be struck: by doing a sufficient amount of exercise at the right intensity to keep ourselves fit and healthy we may be able to improve our prospects of having a baby. Doing too much exercise at the wrong intensity could mean we harm our chances. In the rest of this Section I will set out some guidelines to help you achieve the right balance.

The right balance

To achieve the right balance it is not just the amount and intensity of the exercise that we need to consider, it is our ability to recover from each session. You may be aware that exercising stresses the body and in response our body repairs itself and also prepares to deal with the new levels of activity. This is part of our body’s survival mechanism. It knows that if it is subjected to continued exercise stress it needs to be ready to deal with it. Each time we exercise we get fitter because the body (assuming adequate rest and nutrition) repairs and prepares itself. Once it has done this we are then able to exercise harder which then means the body needs to repair and prepare again. This is a virtuous circle and over time leads to significant improvements in fitness.

The amount of rest we need depends on a number of things including our current fitness levels – generally the fitter we are the more quickly our body recovers – the volume, intensity (how hard we push ourselves), type of exercise, how busy/stressful our lifestyle is and how much sleep we get.

For those that already exercise you may have a reasonable feel for how much you can do, of which type and how much rest you need. For those who do not currently exercise, or do not exercise much, the following will provide a guide:

Volume: how much exercise should you do in each exercise session and in each week? The answer to this is linked to the type of exercise that you do. For example, 45 minutes of yoga is very different to 45 minutes of weight training. You could probably do yoga every day (if you had the time and inclination!) but weight training every day would likely lead to overtraining (the cumulative result of your body not having the time to repair itself before the next session) which can result in health problems.

In terms of the duration of each session 30-45 minutes, excluding warm-up and warm-down, is about right for the typical person. It provides enough time for a decent session and is short enough for most people to incorporate it into their lives.

For the number of sessions per week, 3 is a good rule of thumb, leaving a day in between each session for recovery. What you do during these sessions is discussed further below but doing a variety of different things will help cover all bases and keep things fresh. If you have specific areas that you would like to address, such as being overweight and wanting to lose fat or being stressed and wanting to be more relaxed it will be most effective to focus on specific forms of exercise that can help with those things.  

Intensity: how hard should you push yourself during each workout? To get fit, or fitter, we need to push ourselves to do something that is a bit harder than what we are used to. This is what triggers the body’s adaptation mechanism. Assuming that you are healthy and your doctor has given the ok, whatever level of fitness you start from, subject to the other guidelines on volume and intensity, you should strive to do a little bit more each time you exercise. That may be something such as running a bit further in the same timeframe, using a slightly heavier weight or holding a stretch for a little bit longer. Continually making small improvements over time can add up to dramatic changes. We do however need to be conscious of the studies and not exercise at too high an intensity.

If you are just starting out with exercise then take things slowly at first. Most people find that starting out is the hardest time because the body simply isn’t used to exercising. The same is true if you have had a long lay-off. I remember the first session my wife did at the start of our preparation. It was New Year’s Eve and I took her along to my gym to show her some exercises. For various reasons she had not exercised properly in a long time and by the end of the session she was crawling on her hands and knees to get to her water bottle. We clearly pushed things too hard that day but she is the sort of person that likes to give it everything. After throttling back, two weeks and 5 sessions later she was doing the same exercises using the same weights with ease.

Type: which type of exercise should you choose? This decision is a balance between choosing something that is effective and something that you enjoy. The more you enjoy something the more likely you are to stick with it. For example, yoga is a great form of exercise with numerous benefits, both physical and mental but if it is the only form of exercise you do your fitness improvements will be limited.

In terms of the most effective forms of exercise to improve health generally, studies show that weight training and interval training lead the way. Many women shy away from weight training believing that it will make them muscular, bulky and masculine but this is not the case. There are many reasons for this, not least that women have different proportions of hormones to men.

Weight training leads to a host of health benefits including:

1. mproved heart health[14] [15]
2. reduced risk of osteoporosis[16]
3. better quality of sleep[17]
4. increased energy levels[18]
5. reduced stress[19]

Interval training has been gaining in popularity in recent years and with good reason. Interval training simply means choosing a type of exercise and alternating bursts of exercise and rest. There are a growing number of studies that show its effectiveness. For example, it has been shown that interval training:

1. decreases the chances of dying from any cause[20]
2. reduces body fat, particularly belly fat, more than standard aerobic exercise[21]
3. lowers levels of bad cholesterol[22]
4. improves endurance even though only short bursts of exercise are used[23]
5. produces greater improvements in fitness generally than standard aerobic exercise[24]
6. is efficient, allowing you to achieve greater results in a fraction of the time[25]
7. improves blood pressure[26]
8. slows down the ageing process more than other forms of exercise[27]
9. improves heart health[28] [29]
10. is more enjoyable than standard cardio meaning we are more likely to stick with it[30]

On top of these benefits interval training requires no special equipment and it can be done (almost) anywhere.

For men the type of exercise used in interval training may be important. Specifically, cycling has been shown to have a negative impact on sperm quality. It has been known for a while that competitive cyclists suffer from lower sperm quality and a study[31] on “normal” cyclists showed that even a moderate level of cycling can have negative effects. The study involved 2,481 men undergoing IVF and found that men who cycled for more than 3 hours per week were twice as likely to have low sperm concentration.

As weight training and interval training are two of the most effective forms of exercise let’s look at how to design effective training programmes.

Weight training

I will provide an example of a weight training programme at the end of this section. A single programme will only be of limited use so I will first give you the tools to design your own. One of the biggest mistakes people make with weight training is using the same programme for months on end. The body adapts very quickly so you have to change things around every 4-6 weeks otherwise our progress is likely to slow down or even stop. Changing things also helps to keep workouts fresh and interesting and in turn helps keep our motivation levels high.

There are numerous variables that come into play when it comes to programme design so to try to keep things as simple as possible I have split the programme guidelines into the following:workout frequency

1. workout duration
2. exercise selection
3. set and repetition ranges
4. weight selection
5. rest intervals
6. warm-ups
7. warm-downs
8. change frequency

Workout frequency: if you choose to weight train aim to do at least 2 sessions per week to achieve results. Anything less than that and you are unlikely to generate sufficient “training effect” to progress. If you cannot commit to doing at least 2 sessions per week then it is probably worth choosing other forms of exercise instead. If you are able to commit you should plan on having at least 1 day’s rest between each session.

Workout duration: 30-45 minutes excluding warm-up and warm-down is a good rule of thumb.

Exercise selection: when weight training, unless you are trying to strengthen or increase the size of a particular muscle group, it pays to focus on exercises that give most bang for the buck. These are known as compound or multi-joint exercises. In other words, exercises that involve more than one joint movement to perform. These exercises allow you to work multiple muscle groups at once making them much more efficient than trying to exercise each muscle individually.

Multi-joint exercises can be divided into 4 categories according to the type of movement:

1. upper body push, where the upper body pushes or presses a weight away from the body or the body away from an object. Examples include press-ups, bench presses and overhead presses
2. upper body pull, where the upper body pulls or rows a weight towards it or the body towards an object. Examples include chin-ups, bent-over rows and lat pull-downs
3. quad-dominant leg, where there is a significant knee bend that primarily works the upper thighs (quadriceps, hamstrings and glutes). Examples include squats, lunges and step-ups
4. hip-dominant leg, where there is significant bend at the hips that primarily works the muscles at the back of the body (back, glutes, hamstrings and calves). Examples include the various different types of deadlift

Here are some more examples of multi-joint exercises, categorised by type of movement:

Nb. because it is difficult to describe how to perform these exercises in words you should have a gym instructor take you through how to perform them safely and effectively.

You will see that most of these exercises require only basic equipment. This is because “free weight” exercises, as they are known, are the most effective. Exercise machines dictate planes of movement and can not only cause injury they remove the need for the muscles to stabilise the weights which makes the exercise easier but less effective.

For each programme choose 1 exercise from each category, varying your choice from programme to programme.

Set and repetition ranges: the possible combinations of sets and reps is infinite however for all but advanced weight trainers using a yardstick of a total of around 25 reps per exercise provides a good guide. This number of reps can then be divided between sets in a variety of ways. Different rep ranges result in different effects:

1. low reps in the 2-5 reps per set range primarily build strength
2. mid-range reps between 6-8 reps per set build a combination of strength and muscle tone
3. high reps in the 9-12 reps per set range primarily increase muscle tone.

Some of the most effect set/rep combinations are 5 sets of 5 reps (shortened to 5 x 5), 3 sets of 8 reps (3 x 8) and 8 sets of 3 reps (8 x 3). For beginners starting out with 3 x 8 is a good option then move on to 5 x 5 and then 8 x 3 in subsequent programmes.

Weight selection: this is closely linked to the number of reps you do per set. If you are doing 8 reps per set you are obviously going to need to use less weight than if you are doing 3 reps per set. It is important that the exercise is not too intense so choose a weight that is heavy enough that you reach “failure” on the last rep of the last set. Failure means not being able to perform any more reps with proper form. It may take some experimenting in the first few workouts to find the exact weight.

Once you have found the correct starting weight aim to increase the weight slightly each workout whilst maintaining correct form. This is important as it will help ensure that you progress whilst helping to prevent injury. If you find yourself straining and using incorrect form you have increased the weight too far.

Rest intervals: choose a rest period of somewhere between 30 and 90 seconds between sets and vary the length of rest periods each time you change your programme.

Warm-ups: exercising cold muscles and joints increases the chances of injury significantly. It is therefore important to warm up properly. A good warm up comprises a general “all body” warm up followed by an exercise specific warm-up for each exercise you do.

For the all body warm up a combination of dynamic stretches works best. Do not do static stretches (where you stretch a muscle to a certain point then hold it for a period of time) before exercising as this has been shown to increase the risk of injury and decrease strength[32]. Spend one minute doing each of the following dynamic stretches at the beginning of each workout (again ask your gym instructor to show you how to do these correctly):

1. arm circles
2. arm swings
3. leg swings
4. high steps

Once the all body warm up is done you should feel “looser” and more flexible but it is still important to do exercise-specific warm-ups. Before each exercise pick a light weight that you can use for 15 reps and perform two sets of the exercise for 15 reps with 60 seconds’ rest in between. You can then go on to perform the exercise.

Warm-downs: when you have completed the exercises don’t just run for the shower. Take 5-10 minutes to perform some gentle static stretches to warm down. Stretch your muscles to a point where you feel a mild stretch and then hold the position for 10-20 seconds. Stretching can, if done incorrectly, cause injury so seek out an instructor at your gym to teach you how to do them properly.

Change frequency: a weight training programme is only as good as the time it takes our body to adapt to it. As mentioned above after a while our body will adapt to any programme. There is no point putting all the effort in to get diminishing returns. Therefore, change your programme every 4-6 weeks to help ensure continued progress.

Example weight training programme:

Interval training

As with weight training there are many variables when it comes to interval training. The basic idea is that you perform short bursts of an exercise, rest for a period and then repeat the cycle a number of times. As with weight training I will set out some guidelines for you to design your own interval training programmes and will include an example at the end. The variables for interval training are similar to those for weight training:

1. workout frequency
2. exercise selection
3. intensity of effort
4. interval ranges
5. rest periods
6. set ranges
7. warm-ups
8. warm-downs
9. change frequency

Workout frequency: I would suggest aiming to do no more than 2 sessions per week. If getting fit is your goal and not, for example, fat loss 1 session may be sufficient depending on what other exercise you do. The session(s) should be at least 1 day away from each other and from weight training, if you choose to do that, to give yourself enough time to recover.

Exercise selection: intervals can be performed using many exercises but in the interests of making things as easy as possible to stick with the exercises listed below do not require any special equipment:

1. sprints
2. burpees
3. alternating leg lunges
4. star jumps
5. squats
6. squat jumps

Intensity of effort: the normal recommendation is that intervals should be performed at 90-100% intensity (ie. maximum or near maximum effort). However, the studies described above suggest that this level of intensity may actually harm our fertility so we must reduce the intensity levels to “moderate”. This will make the intervals less effective from the narrow perspective of “getting fit” but of course there is a bigger goal here and we must not lose sight of that. As everyone is different you will need to gauge what is “moderate” yourself. An intensity of around 60-70% of maximum effort should be about right.

Interval ranges: interval training involves short, sharp bursts of effort followed by a period of recovery so you may be surprised at the brevity of the intervals. Depending on your current levels of fitness each burst of exercise should be between 30 and 60 seconds. If you are unfit or are new to intervals, start with periods of 30 seconds.

Rest periods: the studies in this area suggests that rest periods should be between 1-3 times the length of the exercise period. So, for intervals of 30 seconds, each rest period should be between 30 and 90 seconds long. Again, if you are unfit or new to intervals, start with rest periods of 90 seconds then reduce the rest period as your fitness improves.

Set ranges: for interval training 1 set means a burst of exercise followed by a period of rest. So, 30 seconds of effort followed by 90 seconds of rest equals 1 set. How many sets you should do again depends on your current fitness levels and whether you have done intervals before. Beginners should aim to start with 5 sets.

Warm-ups: follow the all body warm-up suggestions set out above for weight training but add in a 10 minute gentle jog. This will serve as the exercise specific warm up.

Warm-downs: again, follow the warm-down suggestions for weight training.

Change frequency: as with weight training an interval programme is only as good as the time it takes our body to adapt to it. Therefore, change your programme every 4-6 weeks to help ensure continued progress.

Example interval training programme:

Exercise for fat loss

If you are outside the ideal BMI range for IVF success then exercise is an important factor when trying to lose fat to get within the range.

Everyone knows that steady state aerobic exercise (also known as “cardio”) is the best exercise for losing fat, right? By spending 30-60 minutes on a treadmill, bike, jogging, etc 3-4 times per week our body will burn off the fat, right? Not so fast, there may be better ways…

There have been a number of studies that compared the fat loss effects of cardio against interval training. For example, an Australian study[33] looked at the effect of doing 20 minutes of interval training 3 times per week compared to doing 40 minutes of cardio 3 times per week. Despite the cardio group exercising for twice the time of the interval training group the cardio group actually gained on average 1lb of fat whilst the interval training group each lost an average of 5.5lbs of fat!

In a study[34] as far back as 1994 researchers compared a 20 week cardio programme against a 15 week interval training programme and found that, even though the interval training programme was carried out over a shorter period, it led to much greater fat loss. The researchers measured the levels of fat under the skin before and after the programmes and found that the interval training participants lost on average 13.9mm of fat but the cardio participants lost only 3.5mm.

One other thing that is interesting about this study is that the researchers calculated the total amount of calories burned during the workouts and found that the cardio group burned 28,661 calories and the interval group burned only 13,614 yet still lost much more fat.

Why is interval training more effective than cardio for fat loss? There seem to be a few reasons:

1. interval training burns more calories following After an interval session our body’s metabolism is elevated for up to 48 hours resulting in more calories being burnt
2. more fat is burned for energy due to the increased release of certain fat burning hormones (catecholamines and growth hormone)
3. intervals decrease appetite.

The studies above used maximum or near-maximum effort levels and for the reasons discussed above it is important to exercise at a lower level of intensity. The result of doing so is likely to be lesser fat loss results but remember the overall goal: IVF success.

Weight training has also been shown to be one of the most effective forms of exercise for fat loss. It both preserves lean muscle whilst creating an optimal environment for our bodies to burn fat. It does this in a number of ways:

1. lean muscle is like an engine that burns calories for fuel so the more muscle you have the more energy you burn and the more energy you burn the easier it is to lose fat and keep it off. This is the opposite of the “skinny fat” phenomenon where people appear to be relatively slim but actually have a high body fat percentage and little lean muscle. Instead of looking firm and toned they look “wobbly”. In one study[35] where participants gained just 1.4kg of muscle they increased the amount of calories they needed by 15%. 1.4kg is just about enough to make someone look toned but certainly not enough to make them look “muscular”. In another study[36] women who weight trained as part of a diet to lose 25lbs were able to lose this amount of fat whilst keeping all their muscle. This meant their daily calorie requirements actually increased by 63 calories. Women who did not weight train lost muscle which resulted in their daily calories requirements decreasing by 259 calories
2. like interval training, weight training increases certain fat burning hormones. In one study[37] this resulted in “resting metabolic rate” (the amount of calories our bodies burn just to keep alive) increasing by 9.4%
3. again, like interval training, weight training burns more calories following workouts. One study[38] showed weight training with short rest intervals caused participants to burn an additional 452 calories in the 22 hours following workouts
4. it increases our body’s ability to burn body fat rather than carbohydrate or protein over time. For example, at the end of a 16 week study[39] participants who did weight training burned 63% more fat for energy than they did at the start of the programme
5. it improves insulin sensitivity which causes less of the food we eat to be stored as fat[40]

Conclusion: discuss with your doctor and with his consent choose interval training and/or weight training over cardio to shift the fat and improve your BMI.