If you are looking to stay fit or get fitter, at some point in your journey arises the question, “How should my focus be split between cardio and strength training?” Following on from this question, arise other related questions and often the thinking and action plan can go awry. Depending on the time horizon you look at, and your specific circumstances and priorities, the answer will vary. Today, I will walk you through how to think through the topic so that you are always close to the right path for you. Whether you are just starting off after a period of sedentary and lazy living or trying to push your athletic performance further, this topic is important. Whether you are young and hoping to look attractive to others or if you are older and hoping to live without accident and disease, today’s topic is important. There will be some areas that you have not given much consideration to, so you will find today’s reading useful.

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Contents

Background Motivation
Basic Terminology
Satisfying the 2 Sets of Cousins
1234Health-Based Measures
1234Skills-Based Measures – BS CRAP
Diversity, Blind Spots and Tail Risk
Stage of Life and Other Goals
1234Body Image, Gender, and Age
1234Disease Prevention and Reversal
Planning Processes for Cardio and Strength
1234AND not OR
1234Stage of Fitness
1234Interactions
12341234The Interference Effect
12341234The Original Fear
12341234The Latest Evidence
12341234The Wise Action Path
1234Planning over Horizons
12341234Detraining
12341234Maintenance Mode
12341234Overtraining
12341234Within a Lifetime
12341234Within a Year
12341234Within a Week
12341234Within a Day or within a Session
1234Nutrition
Tracking
Parting Message

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Background Motivation [top]

Reliable population-wide statistics do not exist for any country, but my experience over the last 20 years tells me that no matter which country you are in:
– the fraction of adults who do not exercise is significant compared with those who do exercise
– the fraction of the population who do both cardio and strength training is low
– more people do some form of cardio than strength training
– of those who do cardio, the fraction that do strength training is small
– of those who do strength training, the fraction that does not do some form of cardio is relatively small

What these insights hint at inihs that the state of public health can be improved significantly, and so the immediate and long-term cost to the individual and society can be reduced significantly if more of us incorporate both cardio and strength training in an appropriate manner.

Basic Terminology [top]

We use the expressions “doing cardio” or “doing strength training” in our normal speech so it is good to understand what precisely we mean. By “doing cardio” we typically mean something that pushes our heart to work harder than usual for a duration longer than a few minutes. By “doing strength training” we are referring to pushing or pulling against some load or resistance to work a specific muscle or a certain set of muscles with a level of effort that is difficult enough that we cannot continue to do it for a long duration.

Using those descriptions, easy walking is not cardio – it does not really push the heart much for a healthy person. Similarly, continuously climbing a hill for 2 hours without a break with a backpack is not quite strength training (though it works on muscular endurance). If the load of the backpack and the steepness of the incline was such that you could only manage it for 60 seconds up a slope, then we would consider it to be strength training.

Popular examples of cardio include running, swimming, and cycling. Using our definition of cardio, activities such as dancing and hiking uphill are also forms of cardio.

For strength training, the most popular venues are gyms with free weights and machines, yet open-air community parks with strength training equipment can also be excellent. And, if you cannot get out of the house for it, you can do strength training at home with resistance bands and free weights (dumbbells and barbells) or even just your own body weight.

Satisfying the 2 Sets of Cousins [top]

Whenever you exercise, you are trying to satisfy some physical fitness goals. Specifically at the physical level, your fitness goals can be split into 5 health-based measures and 6 skills-based measures. It is important to note how just “doing cardio” or just “doing strength training” or even doing both regularly will not necessarily automatically ensure that you satisfy all the 11 cousins discussed below.

Health-Based Measures [top]

As a quick reminder from an earlier article, the 5 health-based measures of fitness are:

1. Muscular strength
2. Cardiorespiratory endurance
3. Muscular endurance
4. Flexibility
5. Body composition

Numbers 1 and 2 on the list can be covered with sessions of strength training and sessions of cardio respectively. How about numbers 3, 4 and 5? Let us consider them in turn.

Remembering the SAID Principle that I touched upon in an earlier article, you can guess that muscular endurance will improve for very specific muscles when you do cardio. For example, the working leg muscles are those for which endurance is targeted when you run 5km. A similar effect can also be set up for certain strength training movements. Muscular endurance for working muscles may improve when doing strength training depending on what you do during a strength training session. Doing 40 pushups in a single set requires the working muscles (chest and triceps) to have considerable muscular endurance. However, if you do 3 reps of a heavy-load bench press to develop muscular strength in the chest and triceps you will not be targeting muscular endurance.

If you ensure an adequately large range of motion during strength training and have an intelligent sequence of movements you will automatically improve flexibility while doing strength training. The dynamic stretching before and static stretching after your workouts will also improve your flexibility. You could do purely flexibility sessions with specific postures from yoga or tai chi – 2 modes of physical exercise mostly associated with flexibility. In addition, you could intelligently flip them around and get a cardio workout from either yoga or tai chi – do them in a way that pushes your heart rate high enough. Similarly, you could use them to get a strength training workout if you did them in a manner that stimulates the relevant muscle fibres to a level they are not normally used to.

Finally, we hope that doing cardio or strength training also helps improve our body composition but the details will matter. What would you like to do for increasing or maintaining bone mineral density? Do you want to look lean and muscular like a competitive swimmer? Do you want to look lean but not particularly muscular like a distance runner? Do you want to look bulked up and muscular?

Skills-Based Measures – BS CRAP [top]

To help you remember the 6 skills-based measures of fitness, I created the mnemonic BS CRAP for this article some years ago. As a reminder, the measures are:

1. Balance
2. Speed
3. Coordination
4. Reaction Time
5. Agility
6. Power

If you only swim for cardio, you will not work on your balance much. If you only do strength training at a gym, you are unlikely to have good reaction times. If you only run on a treadmill, you are unlikely to maintain agility and reaction time nearly as well as if you run on uneven trails (my village) or uneven roads (Mumbai). As part of your running for cardio, you could do sprint intervals for speed. And if you do plyometric jumps, they will improve power but only in your jumping muscles. Even if you develop great muscular strength (and size), your balance, coordination, reaction time, and agility will develop very differently if you have a routine of just using machines at a gym versus (also) using outdoor equipment (e.g. public park) for increasing muscular strength e.g. jumping up to grasp at monkey bars to do pullups.

To summarize this section, we can say that “the money is in the details” and so the SAID Principle is what you will need to bear in mind if you want some contribution to BS CRAP from your chosen form of cardio, or for planning the way you do strength training. Remember, nothing stops you from mixing and matching the mode of exercise you choose – be creative to achieve your goals. Keep the 11 cousins happy.

Diversity, Blind Spots and Tail Risk [top]

Depending on the convention you use to count them, your body has between 600-840 muscles. To appreciate that each muscle contracts to work on a different task is important because it is the work that they do that leads to outcomes. If your posture is not great and you do strength training without intelligence, you might worsen your posture – see those unintelligent weight training enthusiasts who look like apes? If your goal is to simply look big and bulky then you could do strength training without much thought, even develop a big chest and gigantic biceps but you might hurt your back one day and suffer for years. Make your strength training functionally useful and develop yourself intelligently. Be aware of the diversity of your muscular system and the specificity implied.

Even if they also do strength training, the classic blind spot for those who do large volumes of cardio is jumping to the conclusion that they are now invincible against cardiac disease. The blind spot arises because of the narrow belief that building strong heart muscles is enough to prevent a heart attack or stroke. The bottleneck that may well lead to disastrous outcomes might be holes in your diet plan or a deficiency of good quality sleep.

Always be clear that any form of exercise involves some risk and, therefore, while investing in exercise we must be safe from both the obvious risks (e.g., falling off a bicycle, tripping when running) and the rare but extreme tail risks. As with investing, protect yourself from a gambler’s instinct, seek out risks that you can control and maximize your returns with, and do not risk losing so much of your capital that you never get back to the state of health and wealth you had.

Stage of Life and Other Goals [top]

There is almost infinite variation at a detailed level across individuals and any planning cannot ignore the specific preferences you have or constraints that you face.

Body Image, Gender, Age [top]

If you have a negative body image and would like to improve your mental health in that area it is important that you take strength training and cardio seriously as part of your activity planning. Understand that both types of activities are important as part of a weight loss program. There can also be a tendency for young men to focus more on strength training and ignore cardio. On the other hand, many females avoid strength training because they have a biologically incorrect fear that they will soon look muscular and manly. And, in most cultures, there is a misunderstanding that building and maintaining muscle is something that young men do and that it is very OK for children, women and the elderly to avoid it.

The forms that cardio and strength training take may vary based on the circumstances, but doing them both can help satisfy many of the 11 cousins.

Disease Prevention and Reversal [top]

The growing body of empirical evidence makes it clear that the best way to live a long healthy life, to have a long Healthspan, is through the prevention of disease. Not investing in your internal wealth and hoping that you will reverse common lifestyle diseases like high blood pressure, diabetes and “bad cholesterol” with medication is a false hope. Treating the symptoms of diseases is radically different from curing yourself of a disease. Having symptom-free good health without medication for any disease that was caused because of a poor lifestyle can only be achieved by lifestyle. Whether it is the prevention of disease or reversing disease through lifestyle, you must ensure that both cardio and strength training are part of your action plan.

If you want to focus on the prevention of all future diseases, or if you want to reverse and then cure a disease you already have, get in touch with me.

Planning Processes for Cardio and Strength [top]

Let us now consider various topics related to doing cardio and doing strength training and how we might fit them into your plan for life.

AND not OR [top]

In case it has not become clear to you yet, we are not discussing whether you should do cardio or strength training – you must do both. The discussion is about how to do cardio and strength training. (Read about the much-feared “interference effect” below.) In addition to doing both cardio and strength training, you must ensure that you improve all 11 measures of fitness especially because of their importance as you get older.

Stage of Fitness [top]

If you have been sedentary and unfit for a while then simply getting started with something as basic as brisk walking or using a rowing machine will be good to get into a habit of regular exercise. The trick is to be prudent and to start off with small steps and progress gradually – this gives your body and mind some time to adapt to the kind of beneficial shocks it has not been used to for a long time. Once you have a rhythm of regular exercise for 2-3 weeks, you must do both cardio and strength training. You could even start off with both i.e., some form of cardio and some form of strength training from week 1. However, you must learn to do that correctly and safely – if you are not sure how, get in touch.

If you consider yourself to be quite fit and are attempting to achieve better fitness outcomes by doing both cardio and strength training then you will have to consider the various topics below and solve an optimization problem to flesh out the details specific to your goals based on your current health status, preferences and constraints, and the time-horizon for which you are planning your actions. Once again, if you are not sure how, get in touch.

Interactions [top]

With the internal and external resources that you have, including limited time available for investing, it becomes important to understand the interactions between cardio and strength training.

The Interference Effect [top]

A perfectly reasonable question one might consider is, “In what way might cardio be negatively interfering with strength training or vice versa?”

The Original Fear [top]

A widely cited paper from 45 years ago with the title “Interference of Strength Development by Simultaneously Training for Strength and Endurance” concluded that doing both cardio and strength training does not negatively impact endurance improvement but does negatively impact strength development. That paper sparked a lot of debate and is often called “the Hickson paper” by researchers in the field. No single and first study to answer an important practical question is perfectly designed to definitively answer that question in the context of many different real-life situations possible. It is for that reason that many more research studies by exercise scientists were conducted over the next 40+ years to answer the question, “Does doing cardio in parallel with strength training negatively affect strength development?”  What did they find?

The Latest Evidence [top]

A recent combined analysis of 43 separate studies in this paper confirmed that combining cardio and strength training does not hinder muscle size or the development of maximal strength except if taken to extremes. So, do not live in fear that your sustainable cardio routine for life is adversely affecting the gains you are targeting from your sustainable strength training routine.

The Wise Action Path [top]

Now, here is some practical wisdom. In general, in any sphere, if over many years and after many studies there is still some doubt about the existence of some marginal effect, the practically wise decision to make is that the potentially negative effect is not effectively relevant at a daily practical level for the average person. We can use that wisdom in our context of the interference effect and incorporate both strength training and cardio.

At the extremes, a professional bodybuilder might be advised to not run a marathon when bodybuilding competitions are her thing and to keep her cardio workouts at a moderate level. Even for her, doing no cardio would be inadvisable.

For the rest of us, it would make sense to ensure that we do include non-trivial amounts of strength training and cardio in a typical week. In fact, this combined analysis of 11 studies of the general population concludes that if doing only strength training is associated with a 21% reduction in all-cause mortality, then a combination of strength training and cardio is associated with a 40% reduction in all-cause mortality.

Planning over Horizons [top]

Depending on the horizon you consider, how you plan your cardio and strength training will vary. You must consider every horizon and work out a plan to achieve your goals around various constraints. As you plan your training you must be aware of the impact of two extremes – taking very long breaks between workouts versus training too intensely too frequently. It is during periods of rest that repair occurs and gains arise. Sleep is the best form of rest, so ensure that you get enough of it of high quality – that is how you will benefit from both your cardio and strength workouts. The key action philosophy that we want to bear in mind is the importance of targeting a large ROTI.

Detraining [top]

Detraining is the loss of fitness and physiological adaptations you experience when you reduce or stop your regular exercise routine. It will also happen if you choose to stop cardio but continue the strength training or vice versa.

Taking too long a break will decondition you. The speed at which you detrain will depend on various factors and it is prudent to assume that you will detrain faster than what the internet will tell you but at the same time do not be paranoid about it. Purunoia is best – it is wise to protect your internal capital and grow it over the long term.

Maintenance Mode [top]

There may be times when the rest of your life affects your workout plans. Then you must keep things in maintenance mode. That means not skipping workouts completely but keeping them at a level that allows you to resume where you left off without much drop in performance or ability. Sometimes you may want to keep your cardio in maintenance mode while you focus more on strength training. At other times you may feel it is better to keep the strength training in maintenance mode while you ramp up your cardio. The key to success is conquering consistency.

Overtraining [top]

If detraining is at one end, at the other end of the spectrum is overtraining. This can happen even if you are not doing too frequent and too intense workouts. How so? If your nutrition and rest between sessions are not adequate you will harm rather than help yourself with the workouts you are investing in. Be especially mindful when you are ramping up both your cardio and your strength training – you will need even better sleep hygiene to get value from the time you invest in exercise.

Within a Lifetime [top]

What we call “exercise” is for life. The form of exercise may change but the need to ensure that all those 11 measures of fitness are at acceptable levels is key.

What you do as strength training in a gym might be very different when you are 19 versus 90.

At 19 you can play a game of badminton as your form of cardio after 30 minutes of weight lifting, but at 90 walking 10 minutes each way to buy your daily groceries can combine both your cardio and your strength training.

The wise action is to do both cardio and strength training from 19 to 90 so that you increase your chances of reaching 90 without any health problems.

Within a Year [top]

Depending on where you live during the various months of the year, and the weather patterns in each of those places, you may change the form of cardio or strength training that you do. If you always have access to a gym 24×7 for strength training the planning will be different from the situations where you need to use public facilities (e.g. park equipment) to do strength training. If you normally do strength training at home and then go for a 3-week break to a mountain cabin your strength training method will need to be adjusted so that you do not have a detrimental 3-week break from strength training.

Do not allow your location or the time of the year to determine the growth or maintenance of your internal wealth. Be creative to flourish! Do not allow boredom to creep in.

Within a Week [top]

Adaptation to get better after the beneficial stress of any workout happens in the period between your workouts and requires time defined by the laws of biology. Through optimum nutrition and rest to your body’s systems that were given the beneficial stress you can try to minimize the required duration between successive workouts. At a practical level, i.e. if you are not a professional athlete competing at the highest levels, a rhythm of doing cardio 3x per week and strength training 3x per week works smoothly in a typical week even for a busy adult. The trick is to keep a gap of at least 48 hours (or longer for certain age, gender, body parts, and training intensity combinations) between sessions. This would mean that you can follow a pattern that is something like:

Mon, Wed, Fri – strength training
Tue, Thu, Sat (or Sun) – cardio

The 7^th day freedom gives flexibility such that you can adjust the weekly rhythm when business, social or emergency events arise while still managing to not train the same sub-systems intensely 2 days in a row. For example, if your cardio workout yesterday was an intense run then doing an intense lower-body strength training session at the gym today will cause you to regress rather than progress. It makes no sense to destroy gains that you could have had from each session if they were, instead, separated by 72 hours (3 days).  Note that I am referring here to overtraining, not the interference effect. It is also important that you distinguish between fatigue and being low on fuel.

Within a Day or within a Session [top]

There is a non-trivial risk of overtraining, possibly leading to injury, if you frequently do high volumes of both cardio and strength training without long enough rest durations in-between.

There is also a practical “fixed admin cost” on either side of a workout if you need to gear up before the workout and post-workout you need to have a shower and be dressed again for the rest of your day. So, if your strength training and cardio sessions are separated by a few hours on the same day then you will have to pay the fixed admin cost twice – something you will be tempted to avoid.

So, if you do decide to do both strength training and cardio in the same session, it is better (safer and more effective) to do strength training first and then cardio, when they are done in the same session.

In discussing the interference effect this review paper confirmed that doing cardio will not adversely affect gains from strength training for you. However, gains in explosive strength (think “discus throwing”) may be reduced, particularly when both cardio and strength training are done within the same session. So, if you are looking for explosive strength, avoid doing both cardio and strength training within the same session, and if you must, then do the strength training first and then the cardio.

Nutrition [top]

Whether it is strength training or cardio, movement happens because of muscles contracting and so feeding them appropriately is critical for both fuel and function. Movement happens around joints and they need to be in good health too with appropriate nutrition. There is a continuous breakdown of tissue and rebuilding whether you are in a phase of progression to competition or just in maintenance mode. All the flow of liquids, gases and solids within your body happens because of your heart pumping. You must not let the blood circulation system that transports nutrients and waste metabolites be at risk of clogging up. While staying away from the protein obsession that seems to have gripped most of the world, you can stay on track to faster recovery and easier progress with less pain and soreness by following a diverse whole food plant-based diet. Acute (short-term) inflammation is desired as a response to exercise, but your food must not add to that inflammation. Use your nutrition to reduce inflammation and oxidative damage when you are in daily periods of rest, feeding, digestion and repair.

Inappropriate nutrition is a problem of equal if not greater magnitude than the problem of not getting appropriate exercise. If you are investing time and energy in your internal wealth through exercise, do not expect it to be able to overcome the negative impact of poor eating. Just like you are using cardio and strength training to increase your internal wealth, use nutrition to invest similarly. If you want expert advice on nutrition, get in touch.

Tracking [top]

Keeping track of your cardio and strength training workouts will help you in many ways. Whether to confirm that the interference effect is not real for you, or to understand how you can be in maintenance mode and prevent detraining, or to make progress towards your goals without overtraining – your log will become your silent but informative feedback companion.

Parting Message [top]

It takes a lot less effort than we think it does to build up a simple habit of doing cardio and strength training a few times a week and keeping it going for weeks, months, years and then decades.

If everything you do is consistent with your core beliefs and desires, then a long and healthy life of joy is pretty much guaranteed to be yours. If you want to be guided in detail, you know how to reach me, and if you found this useful, please do share it with others.

Puru

Dr Purnendu Nath spends his waking hours focusing on helping individuals and organizations reach their goals, to make the world a better place. He speaks, writes and advises on topics such as finance, investment management, discipline, education, self-improvement, exercise, nutrition, health and fitness, leadership and parenting.