Updated: Jan 30
Today exercise enjoys unprecedented popularity. In addition to the thousands of books on exercise, and the thousands of websites, there is an army of ‘gurus’ telling us how often and what types of exercise we should be engaging in.
The field of exercise has grown exponentially over the past few decades. Some of this growth has been positive. Scientific inquiry has strengthened our understanding of the many benefits exercise can confer if we engage in it regularly enough.
However, arguably much of that growth has been unhealthy. The body of exercise has become burdened with way too much non-force producing tissue: aka fat! Thanks to the web, social media, and self-publishing, any Tom, Dick, or Harrietta can communicate their beliefs on what constitutes as correct exercise practice.
Consequently, many people are confused about the very fundamentals of exercise: how often we should do it, and what types of exercise we should participate in.
Exercise Frequently Asked Questions
This article isn’t an attempt to set the subject of exercise aright. As well as lacking the necessary credentials, this author possesses neither the knowledge nor intellectual skill set needed to attempt such a monumental task.
But I know of a man who does possess the requisite academic attainment to tackle the task of untangling the confusion of exercise.
Daniel Lieberman, professor of Biological Science at Harvard University, in his brilliant book Exercised, brings to bear a wealth of research science to the subject of exercise.
As well as answering many questions concerning the correct application of exercise, Liberman deftly debunks the myths that shroud the subject in a pall of contradiction and confusion.
Below, with the help of Lieberman and many other leading figures and institutions in the field of exercise and health, ten frequently asked exercise questions have been answered.
However, here you will receive only an impoverished assessment of the answers to these questions. You’d be wise to disregard the middleman and go straight to the source:
FAQ #1: What does exercise mean?
If you consult the dictionary the word ‘exercise’ is defined as a ‘planned, structured physical activity to improve health, fitness, or physical skills,’ (Exercised).¹
That concise definition pretty much sums up most people’s understanding of what constitutes exercise.
Exercise is the process of coordinating your body through a series of movements for sustained durations. Typically, the intensity of those movements is higher than ‘normal’ everyday movements.
Elevated intensity serves to stimulate physiological systems thus promoting physiological adaptations. Also known as hypertrophy, physiological adaptations result in improved physical fitness. This can, for example, be expressed in increased cardiovascular endurance, enhanced muscle strength and size, and augmented motor skills.
FAQ #2: Why should we do exercise?
Besides the fact that exercise is pleasurable, in part because when we exercise ‘feel good’ chemicals are released, it also confers many desirable health benefits.
For example, exercise has been shown to be effective at controlling or normalising blood pressure. High blood pressure, or hypertension, is associated with an increased risk of stroke and heart attack. According to the NHS 1 in 3 people in the UK live with hypertension – many of whom are not even aware of it.²
However, as Liberman points out in Exercised, blood pressure can stay normal even into old age so long as we eat sensibly, stay active, and engage in regular physical exercise.
This terse introduction into the benefits of exercise is merely the tip of the iceberg. There is a huge mass of benefits beneath the surface.
But by way of summary, if you engage in regular physical exercise, you may be rewarded with one or more of the following benefits:
Lower blood pressure
Reduced body fat
Improved body composition: decreased fat/increased lean muscle tissue
Reduced risk of some cancers
Increased bone density and with it a decreased risk of developing osteoporosis
Improved mood and mental health
FAQ #3: How long a day should you workout
How many times a week we should exercise for, and for how long, is a contentious and as of yet unsettled question. According to the NHS, we should aim for a minimum of 150-minutes of light- to moderate-intensity exercise per week.³ This minimum weekly ‘dosage’ equates roughly to either three 45-minute workouts or four 30-minute workouts.
The WHO provides a more comprehensive outline of how often and for how long we should exercise. Adults aged 18-64 years are advised to engage in ‘150-300 minutes of moderate-intensity aerobic physical activity.’⁴
But if you are training at high intensities, 75-150 minutes is equivalent to longer low-intensity doses.
The WHO goes on to advise mixing exercise modalities. As well as engaging in ‘aerobic physical activity’, the WHO tells us that we ‘should also do muscle-strengthening activities . . . that involve all major muscle groups.’³
Related: Try this whole-body compound exercise routine
Restructuring the WHO’s exercise recommendations into a weekly workout routine would see us do two to three days of cardio interspersed with two days of resistance training. That’s five individual exercise sessions each week.
Dr Michael Gregor, author of the sensational book How Not To Die, advances on the WHO’s weekly exercise dosage. Gregor recommends that we should, at a minimum, aim for one 30-minute exercise session every day.⁵
So, to the opening question – ‘How long a day should you workout?’ – the answers are as follows:
NHS: three to four 30- to 45-minute light- to moderate-intensity workouts
WHO: four to five 45- to 60-minute light- to moderate-intensity workouts
Dr Gregor: seven 30-minute light- to moderate-intensity workouts
FAQ #4: What is the best time to exercise
According to exercise myth, the best time to train is around 5 pm. Apparently, by 5 pm our bodies are fully ‘awoken’, engaged, and our joints are thoroughly lubricated from all those hours sitting at a desk. However, I’m yet to locate research that supports this myth. But then myths never needed substantiating, that’s what makes them so convenient.
Arguably the only answer to the question What is the best time to exercise is When best suits you. Many of us lead hectic, harried lives that almost always revolve around work. And because that incessant slave-driver capitalism never sleeps, some people’s shift patterns are sporadic. Consequently, those people might not be able to exercise at the most appropriate time (this probably accounts for the rise in popularity of 24hr gyms).
Related: Try this 30-Day 5 am Wake Up Challenge
Outliers aside, if you work a typical 9 to 5 job, the best time to exercise is probably either in the afternoon (to get the blood circulating after a morning of sedentarism) or straight after work (to get the blood circulating before an evening of sedentarism).
Exercising too late – say after 8 pm – can adversely impact sleep on account of the increase in testosterone. Early morning workouts are an option but, besides the fact that few people possess the requisite self-discipline to alight for an early-doors workout, exercise myth maintains that the joints aren’t yet adequately greased, thus joint wear is something to worry about.
To sum up, this dismal attempt to answer the opening question, the best time to exercise is whenever you can.
Related: Try this Morning Workout
FAQ #5: Should I do cardio or weights?
From an anatomical and physiological perspective, humans are obviously set up more for aerobic endurance exercise than we are weightlifting and strength training. For much of our evolutionary ascent, the few forms of exercises available included walking, running, combat, and copulation (though for many the latter was more anaerobic as opposed to aerobic activity).
The fabulous fitness industry, with its dazzling trappings and inexhaustible appetite for inventing weird and wonderful ways of whipping up a sweat, is very much a modern appendage. Gyms weren’t commonplace until the late 70s.
Thus, weightlifting and resistance training is, for the human body, foreign forms of physical activity.
Resistance training benefits
However, with that said, science is showing that resistance training confers many physiological benefits. As well as improving general strength, which makes everyday tasks easier, resistance training increases bone density, thus reducing the risk of fractures and breaks, while also strengthening muscles, ligaments, and tendons – which decreases soft tissue damage.
As for whether you should focus your training on cardio or weights, research studies show that a blended approach is optimal for those seeking general fitness. An exercise routine, then, should reflect Tim Spector’s advice on how to cultivate the healthiest diet. The best diet, he tells us, is both varied and rich in wholesome foods (The Diet Myth).⁶
So, you should do cardio and weights. But also, don’t forget to include callisthenics, resistance bands, power bags, kettlebells, boxing training, skipping, tyre flipping, mace training, battle roping, CrossFit . . .
FAQ #6: exercise vs diet?
In the opening pages of his seminal book, How Not To Die, Dr Michael Gregor tells us that 80% of ill-health is caused by the foods we eat.⁷ Type 2 diabetes, classified as a ‘man made’ health condition, and one which afflicts millions of people across the Western world is exclusively a diet-related disease. Obesity, hypertension, coronary heart disease, and many different types of cancer, are all believed to manifest in the presence of poor dietary habits.
In contrast, exercise is said to make up only 10% of the health whole. And while there are many associative benefits of exercise, it cannot compensate for a disastrous diet. No amount of running or resistance training is going to attenuate the health deteriorating effects of the excessive consumption of processed food.
Diet is all important
Because the foods we eat make up such a substantial portion of health, priority importance must be placed on cultivating the best possible diet. Dr Gregor deftly leads us through what has become a subject suffused in contradiction. How Not To Die delivers a veritable cartload of contemporary research concerning the effects of food on health. But Dr Gregor does more than form a nexus between the reader and nutritional research. He also outlines the constituents of a healthy diet while providing helpful hints and tips on how to implement best dietary practices.
In support of dietary intervention, it is highly recommendable to engage in regular physical activity. Exercise can improve and fortify our health in ways that diet cannot (see FAQ #2: Why should we do exercise?).
However, exercise should not be viewed as the panacea of poor nutrition. The age-old assertion that ‘I can eat what I like because I exercise’ or ‘I exercise to eat’ and at best fallacious and at worst harmful.
Related: Try these 10 Super-Healthy Vegetarian Recipes
FAQ #7: Can exercise lower blood pressure?
Since the late 60s, Lieberman tells us, thousands of studies have established a firm relationship between regular exercise and the reduced susceptibility of disease and improvement of health.
Different types of exercise yield different benefits. For example, resistance training can enhance muscular strength and endurance but exerts a negligible improvement in cardiovascular performance.
Aerobic exercise, in contrast, improves cardiovascular performance while also strengthening the heart and lowering blood pressure. This is a consequence of the physiological adaptations that take place when we engage in cardio exercise.
‘Because the fundamental challenge of aerobic activity is to deliver more oxygen at a faster rate to muscles and other organs, this demand stimulates the chambers of the heart to grow stronger, more capacious, and more elastic,’ (Exercised).
These adaptations increase cardiac output – the volume of blood pumped per beat – and vascular efficiency. Furthermore, by augmenting ‘red blood cell count’ and increasing ‘the volume of plasma’ vascular viscosity is reduced which enables the heart to pump blood more easily.
Taken together these improvements in cardiovascular performance serve to reduce both blood pressure and the risk of coronary heart disease.
Learn how to conduct health measurements correctly and accurately. From blood pressure to BMI, this article shows you how: 5 Health Screening Methods.
FAQ #8: Which exercise burns the most calories?
The highest calorie-consuming exercise is cross-country skiing. No surprise there considering that cross-country skiing is essentially running with planks of wood strapped to your feet.
But it’s not just the physical arduousness of this exercise that makes it such a calorie-gorging monster.
The ‘thermic’ properties of the environment in which the exercise is undertaken also account for additional calorie expenditure. Of course, the human body must ‘burn’ more fuel (calories/fat) to maintain core temperature when exposed to cold weather conditions.
For a while, this phenomenon escaped the notice of research scientists trying to understand why Olympic swimmers weren’t fat. This was the conundrum.
Scientists calculated that the typical Olympic swimmer expends around 6000 calories a day during pre-competition training. Yet, they consumed about 8000 calories. A 2000 calorie surplus doesn’t sound like much when viewed next to these towering numbers. But it is still the equivalent of the average male’s daily intake.
So, why aren’t Olympic swimmers fat?
The answer wasn’t initially obvious. That was until some bright spark suggested that spending 6- to 8-hours a day submerged in water colder than core body temperature is going to contribute to the calorific deficit. After some clever calculations and further investigation, it was shown that the thermic properties of the swimmer’s training environment increased calorie expenditure.
I am not, by the way, suggesting that you should start exercising in cold water or sub-zero temperatures. And arguably the discussion has digressed from the question ‘Which exercise burns the most calories?’ To get back on track:
The exercises that burn the most calories are cardiovascular exercises such as cross-country skiing, swimming, skipping, rowing, running, and cycling. But then a whole-body HIIT workout or CrossFit-style circuit (or boxing session) will also consume calories as eagerly as a World Strongman at an all-you-can-eat buffet.
Basically, if burning calories is your concern, train whole-body and at high intensities . . . and don’t neglect your cardio!
Related: for workouts, circuits, and training ideas, see our dedicated Exercise & Fitness Page
FAQ #9: Will exercise help me lose weight?
No, not necessarily. The ubiquitous yet erroneous belief that exercise is the most effective weight-loss intervention ought to be dispelled. As I argued in another Hungry4Fitness article – 4 Fat-Loss Mistakes You’re Probably Making – the human body is hugely efficient at conserving energy. This point can be exemplified by a quirky example.
If you popped into McDonald’s and procured a Big Mac meal – burger, fries, liquid sugar drink, and condiments – you would, if you were foolish enough to actually eat it, consume around 1500 calories: about three-quarters of an average male’s daily intake.
Related: Try these 10 super-health vegetarian recipes
To order, unwrap, and eat that super-processed junk would take roughly 5- to 10-minutes. Well, to burn off the same number of calories, you’d have to run a marathon – which takes the average person 4 hours and 21 minutes to cover the 26.2-miles.
And, may I point out, running is one of the highest calorie-consuming exercises. If instead you were going to offset that Big Mac meal with a typical gym session (reps, rest, repeat), you’d probably have to workout without pause for an entire week.
For sure, exercise can contribute to the reformation of body composition by encouraging the metabolisation of excess body fat. However, diet is by far a more potent weapon in the weight-loss war. Exercise should be practiced as a supplementary intervention. One used alongside the transition to a healthy, nutritious, plant-based diet – a diet devoid of processed foods and Big Macs!
FAQ #10: What exercise should I do?
In Chapter 12 of Exercised, Lieberman debunks the pervasive myth that there is an optimal dose and type of exercise that we should do. ‘How,’ he asks, ‘how can there be a best or optimal amount and type of exercise?’ And besides, ‘what does “best” even mean?’
At first, these questions may sound somewhat contradictory, even controversial (considering the title of his book). After all, over the past 20 years, the health and fitness industry has been brainwashing us into believing that exercise is of paramount importance and that we must satisfy a minimum weekly quota.
150 minutes of physical activity anyone?
However, the point Lieberman is making is that there is no one-size-fits-all exercise dosage. In addition, there are a plethora of contributing factors that can curtail a person’s ability to participate in physical activity. Age, injury, lifestyle, personal circumstance and commitments, cultural background, and, of course, health and fitness aspirations, all play a part in shaping how much and what type of exercise we can do.
With that said, exercise is essential for the maintenance and improvement of personal health. But how do we know what exercises to do and when to do them?
Firstly, you should ask yourself what type of exercise you are comfortable doing. For if you enjoy exercise, your levels of participation are likely to be far more consistent. Concerning exercise frequency, again that factor hinges entirely on your personal circumstances.
For example, a single parent who holds down multiple modes of employment is unlikely to be able to commit to the same training regime as a professional athlete. Perhaps two 30-minute aerobic workouts are all they can currently manage. Coupled with the dietary practices espoused by Dr Gregor, this is still a satisfactory exercise dosage and one that will yield health and fitness benefits.
To wrap up, you should do whatever type of exercise you can do. And do that type of exercise when it is possible for you to do so. If you are able to, diversify the types of exercises you engage in and set yourself the goal of maintaining consistency.
Final call for any more questions
So that brings us to the conclusion of Exercise | 10 Frequently Asked Questions. The aim of this article has been to provide a bit of clarity in what has become a confusing subject. Hopefully, it has succeeded in this endeavour.
However, if we have neglected to answer a question you have concerning exercise, let us know by popping it in the comments box below.
Also, if you believe any of the answers above to be inadequate, misleading, or plain wrong, again tell us! We won’t take offense.
¹ Liberman, D. (2021) Exercised: The science of Physical Activity, Rest and Health. USA. Penguin.
² NHS high blood pressure advice/guidelines: https://www.nhs.uk/conditions/high-blood-pressure-hypertension/
³ NHS exercise guidelines: https://www.nhs.uk/live-well/exercise
⁴ WHO Physical Activity recommendation: https://www.who.int/news-room/fact-sheets/detail/physical-activity (cited online - 2022)
⁵ Greger, M. Stone, G. (2017) How Not to Die. USA. Macmillan.
⁶ Spector, T. (2015) The Diet Myth. London. W&N publication.
⁷ Greger, M. Stone, G. (2017) How Not to Die. USA. Macmillan.