Is fasted cardio just a fad? Or is it superior for fat loss?

The fitness industry is constantly jumping from trend to trend. As coaches we need to develop core values based upon scientific principles and stick to them. When new stuff comes up, we need to think about it, see where it can fit in with our clients, apply it, and collect data to see whether it is working or not.

One of the current trends is training in a fasted state for weight loss. To reemphasize that last part, this tactic is used only for weight loss. Those of you looking to increase performance are best served not applying this approach. For those of you looking to drop a few pounds, let us look at what the science says.

What the Science Says About Fasted Cardio

A study performed in 2010 compared fasted training to fed training over a six-week period. Researchers looked at some key areas and compared the two groups. Training was always performed in the morning and consisted of two sixty-minute sessions and two ninety-minute sessions. 

"Both the fasted and the fed groups increased their glucose tolerance, but the fasted group increased it substantially more."

The fed group was given a breakfast of 675 calories, made up of 70% carbohydrate, 15% protein, and 15% fat. On top of that, they were given 1g of maltodextrin per kg of bodyweight about ninety minutes before training. The fasted group received this exact same cocktail in the midafternoon. The areas the researchers compared were glucose tolerance, GLUT4, muscle glycogen, metabolic enzymes, body composition, and exercise capacity. The results of the study were quite interesting.

Both the fasted and the fed groups increased their glucose tolerance, but the fasted group increased it substantially more. GLUT4 is a glucose transporter that allows glucose to enter muscle cells. The more of these we have, the more glucose gets taken up into the muscles, as opposed to being stored as fat. GLUT4 transporters increased by 28% in the fasted group and only 2-3% in the fed group.

Glycogen stores increased more in the fasted group when compared to the fed group, but there was no significant difference between intramuscular lipid stores.Increased intramuscular lipid stores are seen in obesity and can lead to insulin resistance and mitochondrial dysfunction.¹ 

"Glycogen stores increased more in the fasted group when compared to the fed group, but there was no significant difference between intramuscular lipid stores."

The only differences in metabolic enzymes were seen in translocase/CD36 and carnitine palmitoyltransferase¹. These two enzymes play a role in our abilities to metabolize both fat and glucose. The fasted group saw an increase of approximately 30% and the fed group did not see an increase. All other metabolic enzymes tested remained the same.

As expected, the fed group had a greater increase in VO2max, but the fasted group showed a greater increase in fat oxidation. As I stated previously, fasted cardio is not a way to increase performance, but instead to lose weight. With less glucose present, it is no surprise that the fasted group showed greater fatty acid oxidation for energy.

The Practical Side of Fasted Cardio

There are other studies that show similar results as the one presented in this article. After reading that study and hearing that other studies back up these findings, you may be ready to jump right into a fasted cardio weight-loss routine - but it’s not for everyone.

"[K]ey areas to assess are sleep, vitamin D, stress levels, exercise routine, and diet. If all of these are squared away, then give fasted cardio a try."

I have messed around with the fasted cardio component with myself, as well as with clients, and I have experienced a mixed bag of results. For some it worked great, but for others it didn’t. This is something you may have to mess around with for a period to see if it helps. Before doing that, I encourage you to assess your lifestyle and improve upon areas that may be weak. Some key areas to assess are sleep, vitamin D, stress levels, exercise routine, and diet. If all of these are squared away, then give fasted cardio a try.

There are some key points to keep in mind if you do decide to try it:

• This study was performed in the morning, and I encourage you to do the same. Waiting until the afternoon or evening to work out while fasting all day may be too much of a stressor and could have the opposite of the desired effects. 
• I also encourage you not to make the fasted cardio something intense. Low-level aerobic activity between 70-80% of VO2max should suffice. Anything more intense may also become a stressor. 
• Make sure you take in carbohydrates with your first meal. I ran into this problem with quite a few clients. We use a paleo diet template, and I encourage my clients to get their carbs in the afternoon or evening. This created the habit of them having a large salad with meat and very little carbohydrates for lunch. This didn’t work well for coming off a fast. So, if this sounds like your current lunch make sure to add some fruit or sweet potatoes to it.

Those of you who have tinkered with fasted cardio I would like to hear from you. Let us know how you implemented it, for how long and how well it worked for you. Your experiences may be able to help someone else trying to lose a few extra pounds.

The Role of Aerobic Exercise and Diet in Weight Loss

When it comes to losing weight, there is often a difference between what clients expect and what a trainer wants them to do. Many clients believe you need more exercise, whereas coaches often believe diet yields the greatest improvements. In a recent study published in PLoS ONE, researchers reviewed the literature to find the truth.


What the research says:

• Aerobic exercise alone caused significant weight loss.
• A combination of diet and exercise had best results for weight loss and related health factors.

Study Design

The research team examined past literature on the effects of diet and exercise on long-term weight loss. The studies they looked at had to be peer-reviewed. The research was also required to cover either an active weight-loss period of six months (although many were a year long) or a shorter weight-loss period with a longer follow up (most lasting two years in total).

Results

There were twenty studies total that fit the requirements noted above. Here's a summary of some of the important findings:

• Exercise and Weight Loss: The researchers found that clinically significant weight loss can be achieved through aerobic exercise alone. However, there was a greater amount of weight lost in the programs that used diet alone. Not surprisingly, diet and exercise together were the best option.

• Health Factors: One of the reviewed studies compared diet to exercise in terms of disease risk factors, and there were no apparent differences between the two plans. Similar to the weight-loss results, there was a greater magnitude of good health outcomes, such as better cholesterol scores and blood pressure, when diet and exercise were combined.

• Weight Maintenance: None of the plans resulted in great maintenance of the new bodyweight once the weight-loss period was over. When the participants stopped dieting, they couldn’t keep the weight off.

Considerations

The advice from this study is to promote diet over exercise for weight loss and to do both together for optimal results. As the researchers noted, the combination of diet and exercise has more benefit, both for weight loss and other related health effects:

The present systematic review found limited evidence to suggest better long-term weight loss and more favorable long-term changes in body composition and chronic disease risk factors when diet is combined with aerobic exercise compared with either diet or aerobic exercise alone.

 

The researchers also emphasized that there are variations for each individual. For example, if you already eat well and want to reduce fat just a little, it might actually be that more exercise, rather than fewer calories, is the way to go. If you struggle with weight maintenance, the only answer is consistency. Weight regain is a fact of life if you don’t stick to your plan.

The research team called for further studies to investigate the role of additional factors such as resistance training and supervised exercise programs.

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Circuit Training Doesn't Get You Fitter

Humans love black and white. We love definitive. We want everything to fit in a box, be on a list, or abide by rules. The problem with all that is the world and our lives are chaotic and uncontrollable.

Definitions of Fitness

And so it is with definitions of fitness, too. We want to label the world’s fittest man or woman, as if there was one event or activity that allowed you to put such a label on anyone.

Given Ironman’s reputation as the single toughest one-day event in the world, surely the winner could lay claim to the title? But how well would he or she do at the CrossFit Games, another event that also likes to use the same phrase? Or even the Spartan World Championships? And what if you took all those winners and put them in the hills of Afghanistan with a heavy pack on their back and made them march for a few days? Who is the fittest then?

Fitness is defined by the event in which you participate. If you’re a runner and run faster than your competitors, then you are fitter. If you’re a CrossFit Games athlete and beat the opposition, then you, too, are fitter.

The Real Definition of Fitness

But something to note here is the definition of fitness for most textbooks - VO2 max. VO2 max is the maximum amount of oxygen that can be used by the heart, lungs, and muscles during exercise. In other words, this is what most people mean when they use the term “cardio,” i.e. training that improves the function of the cardiovascular system and its ability to use oxygen.

But somehow in the fitness field these days there is this bro-science view that anything that raises the heart rate is cardiovascular training. This creates all kinds of problems for those of us who work in the field because everyone will come through the door with their own understanding of what it means to be fit. The potential for miscommunication is high when you combine someone else’s thoughts with your own version of what fitness is supposed to be. Is it any wonder there are so many unhappy clients?

Anyone who has been around for a while will tell you that you are really only working on three things with a client: range of motion, strength, and “fitness” or conditioning. The degree to which you do so will depend entirely on the jointdefinition of fitness you and the client have come up with.

VO2 max testing.

The Emergence of Circuit Training

Because most people are “short on time” (translation: “I have to get home to post a workout selfie or watch TV”), we end up creating plans that are a mix of various forms of training in an effort to tick as many boxes as we can in as few sessions as possible each week. And this is kind of where circuit training came in.

Circuit training isn’t new. It was created in the 1950s by a couple of scientists at the University of Leeds. The two, Morgan and Anderson, found that a circuit designed of nine to twelve exercises performed for ten repetitions each elicited oxygen consumption values (39% to 51.5% of VO2 max) that met “established guidelines of the American College of Sports Medicine for the recommended intensity (40% to 85% of VO2 max) of exercise for developing and maintaining cardio-respiratory fitness.”¹ (Please note: this doesn’t say that circuit training can develop fitness/VO2max, only that it meets the guidelines based solely on heart rate recommendations by ACSM).

The researchers went on to note that increasing the weight - CrossFitters take note - would actually diminish the ability of the circuits to help subjects achieve their goals, although it would allow them to reach muscular overload with fewer repetitions.

Do Circuits Increase Fitness?

In a 1984 study published in Medicine & Science in Sports & Exercise a researchers noted:

[H]igh intensity variable resistance training produces no adaptive improvement in cardiovascular function. The physiological responses measured during a training session provide evidence that this lack of cardiovascular adaptation may be due to the low percentage of VO2max elicited by this form of exercise.

The first thing to note here is the definition of fitness - VO2 max. I’ll say it again: VO2 max is the maximum amount of oxygen that can be used by the heart, lungs, and muscles during exercise. As such, training that is often referred to as “cardio” should be thought of as training that best improves that function.

And the reason circuit training doesn’t work to improve fitness is because of one missing component. To improve VO2 max you need to be able to contract a large number of muscle fibers simultaneously, increasing the oxygen demand, but you also need to be able to relax them quickly, too. A muscle contracted above fifty percent of it’s maximum will actually prevent blood from flowing into it, thus decreasing the use of oxygen during exercise.

In other words, lifting heavy weights quickly doesn’t even get you close to what is needed to improve VO2 max. As a 1991 study from the University of Georgia showed:

…our data are in agreement with the conclusions in previous studies that using HR/VO2 relationships based on treadmill or cycling data to prescribe the intensity of weightlifting exercise results in lower absolute or relative level of aerobic metabolism than during dynamic low-resistance exercise.

This study was designed to find a relationship between heart rate and VO2 during weightlifting for intensities between 40-70% of 1RM. Interesting to note that 70% equates to approximately ten reps on Prilepin’s Table, and 40% equates to roughly twenty reps. In other words, weights that you can easily handle. At every point the relationship between heart rate and VO2 was roughly half that of traditional “cardio”-based training.

The Definition of Cardio

At this point, people are going to jump all over me because I pretty much just said their favorite method of working out is useless. But read this next bit carefully before going off half-cocked in the comments section. Training that is supposed to enhance the function of your cardiovascular system, so called “cardio,” has to improve VO2 max or it isn’t “cardio.” It’s something else.

So if you want to lift weights circuit style - whether you call it metcon, a WOD, a circuit, or LWF - that’s all fine. Just know it doesn’t actually increase the function of your heart, lungs, and muscular system like you believe it does, no matter how sweaty, exhausted, or close to throwing up you are at the end of it.

You also need to know the drawbacks to this type of work. Weight training, while a great fix for many things, may actually be detrimental to your overall health.

Heavy Lifting May Diminish Your Fitness

Despite weight training making your heart rate rise, allowing you to think that you’re getting a fitness and health benefit from it, the opposite is actually true. In his new book,The Cardio Code, Kenneth Jay wrote about a 1994 study from the American Journal of Cardiology. This study showed, over a cross-section of nearly a thousand athletes of both genders, that athletes from traditional endurance sports have the largest hearts. That makes sense, right? Pump more blood around the body and it will respond by giving you a bigger, stronger pump. However, it also found that athletes from static events like weightlifting have the smallest, but thickest heart walls.

The thickness of the walls of the heart is worth taking a better look into. If you imagine the chamber of the heart that pumps the blood, the left ventricle, is like a cup, and we all start with a roughly equal-sized cup, then imagine what happens if I develop a bigger cup? Clearly, I’m going to have an advantage. My heart will be able to pump more blood from that chamber at the same heart rate as yours, effectively allowing me to work harder before I reach my maximum heart rate.

Now let’s imagine the opposite. Let’s say the inside of your cup has extra clay, making the walls of the cup thicker. You’re going to have less internal diameter to your cup, meaning less blood to pump around your body on every beat of your heart. And this is exactly what strength training does. It decreases the internal size of the left ventricle by thickening the walls of the heart. So despite your heart rate going up when you train hard and lift heavy, you may be actively diminishing your potential fitness.

Remember Why You Train

Before you stop doing WODs or circuit training, just stop to think about why you were doing them in the first place. Remember, fitness is defined by how well we do a chosen activity. If you perform in fitness competitions, then you will need high degrees of muscular strength and local muscular endurance. And given that circuit-style training is often what shows up at the events, you’re going to need to do this stuff in training.

However, if you’re in this for the long haul, not just for competition results in the short term, then you need to think about the health aspect of training, too. Heart health, and therefore also the health of your cardiorespiratory system, cannot be overlooked.

The best way to improve the function of your heart is with time-tested traditional endurance activities like running, cycling, and to a lesser extent activities like swimming and arm cycling (which due to a lower degree of weight bearing and smaller muscle groups being used elicit a lower response). And for freak level fitness results, do both.

How to Build Strength to Improve Running Efficiency

A few decades ago endurance athletes where encouraged to avoid “gym training” for fear that they would develop heavy, bulky muscles. The reasoning was: extra mass without function will inhibit endurance performance.

This makes sense. However, the reason “gym training” was adamantly shunned by the endurance culture was primarily due to it being lumped together with the bodybuilding culture. Of course, the main reason bodybuilders lift weights is to build bulk. They also weight train for symmetry and definition, but the vast majority of their time spent training it to get bigger.

In the early eighties some endurance athletes began supplementing their regular endurance training with weight training in hopes of improved endurance. The results where mixed. While the athletes generally gained some strength, they also gained weight. Therefore their strength-to-weight-ratio showed only very modest improvements, and not enough to justify the energy expenditure in performing the extra workout. In other cases, strength-to weight-ratio dropped. Why? The problem was that these endurance athletes were doing body-building-style workouts, designed to grow muscle size with little or no improvement in functional strength. Of course this resulted in a reduction in the endurance athletes most valued attribute: strength-to-weight ratio.

When it was realized that various training principals and techniques could be reworked to make bulk-less strength gains, gym workouts for endurance athletes were revisited.

While some endurance athletes were embracing gym workouts, there were still those who abstained. It was clear that a finely tailored weight training program could be implemented to build strength without an increase in size or weight, but why would an endurance athlete need strength? And would a few gym workouts to achieve it be worth the extra energy expenditure? Would the “return” on investment be justifiable?

Clearly marathon running is an endurance event, not a strength sport. At least this is what traditional wisdom states. But is it correct? For a marathoner, what advantage is it to be able to lift more weight? As it turns out, it can actually be a significant benefit.

If, for example, two runners are completely equal in every respect except for muscular strength, the stronger will be faster over any distance. The lower percentage of maximum strength needed for each stride will translate into improved efficacy and therefore greater endurance. If for example one runner can squat 10% more weight than another, his muscles will not have to work as hard to move the body forward, which can translate to significant endurance gains. When muscles don’t need to work as hard, they also don’t require as much oxygen or circulating blood and therefore will not put as much demand on the heart, which in turn will lower that rate at which it beats. A significant improvement in endurance will be the result. Greater strength does equal greater endurance. In order to build what is now commonly referred to as functional strength, properly structured gym workouts have been embraced by most all high-level endurance athletes.

While the focus for runners and cyclists will expectedly be the legs, gains in upper-body strength can translate to a significant performance advantage by improving muscle efficacy.

Since the arms are used and upper body engaged, improving the efficacy by which they function will help. Each time muscles contract, oxygen and nutrients in the blood is needed. As with the legs, the arms will draw upon the heart to deliver oxygen, nutrition and remove waste products (lactate) so that they can continue moving fluently with ease. With this being the case, it makes sense to increase the strength of the upper body as well so that it doesn’t become too much of an oxygen draw on the system as a whole and increase heart rate.

Nutrition is a vital part of physical training. Of course the things you eat are the building blocks used to reconstruct muscle tissue the training has broken down. Make sure to consume a nutrient-packed smoothie after each workout. Quick and efficient recovery from each workout is key. The faster you can recover, the sooner you can train again. This is what leads to true gains and will improve your performance more so than any other single principal. That’s why I created the Vega Complete Whole Food Health Optimizer formula. I have a serving after each workout to reduce inflammation and start the regeneration process.

The following program is the one of my routines I perform before I begin a more specific phase, one that converts strength into power. For this one, I perform it three times per week. It is extremely effective, but keep in mind that it was designed for someone who has been weight training constantly for at least a year. Tendons, ligaments and connective tissue need to adapt to a more advanced training program such as this, so not to cause injury. If you are new to weight training, I suggest a more basic program to begin with that will gently allow for your body to adapt. Then you can give this one a try. For basic programs to get you started, you may visit: www.zonfitness.com

This workout is for functional strength gain. It will keep you lean and will improve strength-to-weight-ratio and therefore efficacy, endurance and ultimately running performance as a whole. The “high-return” exercise philosophy is taken from my book Thrive Fitness: Mental and Physical Strength for Life. I have applied this concept to a new program I developed in partnership with ZoN Fitness. It’s called the ZoN Thrive Fitness program. You may download the complete video series and the Mental and Physical Benefits of Exercise e-book that I wrote, as well as 20 plant-based recipes for boosting health and performance for FREE at: www.zonfitness.com

Lower Body:

• Lunges: 3 sets of 15 reps

A good all round exercise that helps develop the stabilizer muscles. Particularly important if you periodically run on uneven ground. Also serves as a good warm-up.

• Ball Squat: 3 sets of 12 reps

This is an ideal exercise to quickly increase over-all leg strength while also building stabilizer muscles along with shoulders.

• Strength Ball Lifts on Balance Ball: 4 sets of 15 reps

Builds lower back strength; helps prevent back injury. Boosts core strength and efficacy.

• Double Crunch with Strength Ball: 3 sets of 15 reps

Strengthens core, and in doing so helps improve posture, form and breathing.

Upper Body:

3 sets of 15 reps on each exercise

Reduces oxygen usage of the upper body while running, thereby lowering heart rate and improving endurance. Also helps to maintain proper, efficient form, even once fatigue had set in.

1. Alternating Hand Ball Push-Up
2. Bent Over Lat Rows
3. Shoulder Press with Push-Up Stands
4. Upright Rows

Workout specifics: Perform lower body exercises two times per week, immediately following your hard runs. The upper body portion can be preformed two to three times per week, on alternate days. Rest 90 seconds in between lower body exercises and 60 second in between upper body ones. You may choose to do abdominal exercise in between upper body sets.

Want Faster 5K Times? Listening to Music Might Help

When I coach runners, I often suggest they do not listen to music. I think there are many benefits to running that can be lessened by listening to music, but I’ve often wondered if this belief is true.

Many successful competitive runners find music to be a mental distraction that helps them push through difficult runs. Likewise, beginning and intermediate runners often find music can provide a tempo when pacing proves tricky. A recent study in the Journal of Strength and Conditioning Research addressed the issue of music.

Study Design

In the Journal study, fifteen competitive male runners engaged in five different running conditions, which were used either during or after a 5K test.

1. Medium-paced motivational songs that ranged from 110-150 beats per minute (bpm) during the 5K
2. Slow motivational songs that ranged from 80-100bpm during the 5K
3. Fast motivational songs ranging from 140-160bpm during the 5K
4. Calm music played after the 5K
5. No music at all

The songs were selected not just for speed, but also for the ability to influence the runners. Before the tests, each runner had his brain activity measured while listening to samples from each playlist to ensure that the songs had the desired effects while at rest.

In addition to measuring performance, the researchers studied heart rate variability, rate of perceived exertion, and mood. Some of these tests were performed just after the run to see if music would aid recovery.

Results

On average, the first 800 meters of the run (the first half mile) was performed faster in the slow and fast motivational music conditions. It was almost ninety percent likely that these two types of music would boost performance. The medium-speed motivational songs had a forty percent likelihood of improving performance when compared to no music during the run. After the first 800 meters, the researchers noted running become more neurologically demanding, which prevented the music from continuing to enhance performance.

Music also provided neurological stimulation that indicated the runners were more motivated before running. They were also calmed by music after their run, which would increase their rate of recovery.

Conclusions

Music provided the biggest improvement in performance during the first half mile of the run. Overall, listening to music, particularly slow and fast motivational songs,improved the time over the initial test by about a little over a minute. Selecting songs you find to be motivational seems to be of critical importance, and both fast and slow music seems to do the trick.

3 No-Nonsense Ways to Build Fitness Through Swimming

I grew up at a time when we didn’t have all the information in the world at our fingertips, just a press of a button away. If you wanted to know something, you either went and found someone who knew all about it or found one of these things called a book on the subject. If you did the latter, you then tried whatever it was you were reading about to gain some experience.

The "Expert" Dilemma

The closest we get to this these days is watching a ninety-second clip on YouTube. On rare occasions, people may attend an actual workshop or certification to learn more about a subject in greater depth, but I’m often left feeling like most fitness certifications are equally as bad as watching clips on YouTube. Without standards, which represent skill and experience in the field, all you have is a bunch of theoretical knowledge. And as anyone who has been around training for a while will tell you, there’s a big difference between some of the things that work in labs and things that work in the real world.

Training can really be broken into three big chunks: flexibility, strength, and conditioning. And while someone can be an expert in one area, it is rare to find someone who actually knows what they’re talking about in two areas, and even rarer to find someone who can talk shop with authority in all three.

The biggest disconnect seems to happen between the endurance and strength people, with both at seemingly opposing ends of the scale. And when it comes to endurance activities, swimming is the hardest for people to understand.

Swimming Is Watery Jiu Jitsu

Just about everything you normally apply to training can go out the window when it comes to swimming. For starters, swimming is difficult because unlike riding and running, you move through water, which has far more resistance than air. Secondly, you aren’t even partially weight bearing, unlike in cycling or running, as the water carries your weight. Finally, the muscles used to power swimming are much smaller and tend to be predominantly upper-body. In normal distance work you use the legs, which have a higher percentage of slow twitch endurance fibers in them.

For this reason, I see a lot of mistakes for people who add swimming to their training. One mistake is that people want to use swimming as a recovery from their regular training. Unless you’re already a good swimmer, you won’t recover much by trying not to drown as you struggle from end to end. While cold water is good for helping sore musclesrecover, most public pools these days are set far too warm, as they want to make sure the kids won’t freeze during swimming lessons. If recovery is your goal, you’ll be better off just getting in and moving around for half an hour, unless you're already a good swimmer.

If your goal is to use swimming to gain fitness, I have bad news for you. Swimming is incredibly technical. Think of it as being like watery Brazilian jiu jitsu – sure, you can muscle your way through it for a while, but ultimately technique wins out. That's why when you start swimming, every session will feel like an all-out effort to avoid drowning, aven though you won't actually be working that hard. What you’re feeling instead is local muscular fatigue from asking muscles to do something they’re not accustomed to.

If you are looking to increase fitness in the pool, here are my three pieces of advice for doing it effectively.

1. Work on Technique

My first piece of advice for anyone who wants to swim for fitness is to put in the technique work. It's going to take some effort on your behalf to become more skilled at swimming. I found this out a few years ago, when I was “lucky” enough to have shoulder surgery. I wasn’t allowed do anything with my arm for three months, so I spent that time doing body alignment and kicking drills. Then I was allowed use my arm gently, so I did other drills focusing on hand placement and how to catch the water.

All in all, I did nearly five months of skill training before I was swimming in earnest again. Funnily enough, I was faster at that point than I had been prior to surgery, yet had done no swim-specific fitness work. The difference was all in my technique and feel for the water.
 

2. Swim Hard

The next thing to keep in mind when swimming for fitness is that while your heart may feel like it’s going to leap out of your chest, you’re simply not working as hard as you do when you run or ride. Your maximum heart rate while running is always going to be higher than it is swimming. The more upright you are and the more load you carry, the greater your heart rate. This is one reason why using normal heart rate zones that you calculated for running won’t help much for swimming.

The second part of this to remember is that you use far smaller muscle groups for swimming than you do for running and cycling, so the load on the heart is less. The moment you stop doing that thing you call swimming, your heart will return to normal. Compare this to good swimmers, whose bodies will glow red from heat increases (because you can’t sweat to cool down in the pool) and who will drip sweat once they’re out of the pool as the body tries to cool itself down.

It might sound a bit odd, but all this means that even a hard session in the pool may only have the same effect on your fitness as a moderate running session, provided you’re actuallya competent swimmer in the first place. Have you ever wondered why swimmers spend so much time in the water? It’s because they need to develop the feel for the water, and because even at high levels of perceived effort they’re just not getting the same adaptation to the heart as a runner might.

If you are swimming for fitness, you need to bust your butt to swim hard. That’s the only way to get your heart rate high enough to get the top-end fitness you can get from running. While the impact on the body will be far lower doing this with swimming than running, the hard fact is that many people will never get to this point without years of dedicated effort.

3. Add Load to the Legs

Years of hard work can be somewhat mitigated if you choose to swim with fins. It may seem like fins would make swimming easier, and you will certainly go faster. But adding resistance for the leg muscles will jack up your heart rate tremendously. I actually recommend that clients who aren’t habitual swimmers only swim with fins for this reason. But don’t do this if you’re training for an open water swim or triathlon – you need to spend time swimming without fins for that purpose.

The three biggest things you can do if you’re looking to increase fitness in the pool are to get some technical coaching, swim hard, and use fins to add load to the legs and drive up the heart rate. Above all, though, put technique first as it will make the biggest single difference to your ability to swim hard for extended periods of time.