Why am I exercising right now?

“Why am I exercising right now?”  I ask myself this question every time I start to warm up for anything that’s not a game of basketball.  I do enjoy the traditional workout, specifically the part where I’m done and full of feel good chemicals.  The difficulty for myself, and most people I come in contact with is getting going.  To get oneself to the actual workout space and then to not just sit in the change room for a half hour, shower and go home.  I think most of us understand that exercise is good and we should do it.  There is enough scientific evidence to show that being physically active and fit has long-term health (mental and physical) benefits.  The question I want to try and shed some light on is: “Why do we need to exercise?”  Once again, this is not a debate about the benefits of exercising, this is an investigation into why good health is dependant on exercise.  For example, we need to eat to stay healthy and sustain life.  Aside from those of us with issues around disordered eating, it tends to be an enjoyable experience that most of us look forward to.  No other animal I can think of needs to schedule time in their day to exercise, in fact most of the ones I see use any spare time they have to relax.  Where does this need for exercise come from and more importantly can I use this information to help people change their relationship with exercise in a positive way?  Well I went looking for answers.  After going down the rabbit hole of paleoanthropology, here is what I found out:

Preface:  I’m not “that paleo guy” walking down the street barefoot in January eating raw buffalo marrow on his way to cross fit.  My diet often consists of the food that my kids throw on the floor and leave on their plates. I exercise whenever I can with no real program and I wear shoes…always…unless its summer when I wear sandals.

Question:  Why do we need to exercise? 

Answer:  Maybe you don’t, it depends.  Do you source all of your food from the natural environment without the aid of machinery and agriculture?  If so then you probably don’t need to do any more exercise because you’re already doing a lot.  Oh you don’t do that?  Ok well you used to, I mean in the sense that all humans used to.  Throughout the vast majority of human history as we evolved through natural selection from apes to homo sapiens and everything in between (a process that took millions of years) our energy output was directly linked to our energy input.  We acquired energy from the food that we had used energy to obtain.  In other words, you had to spend energy to get energy.  These evolutionary pressures shaped our cardiovascular, musculoskeletal and energy systems over that long history and eventually selected us in our current form more or less.[i]   Modern humans likely evolved from a common ancestor some 200,000 years ago in Africa.[ii]  Modern human behaviour started sometime between that point and 50,000 years ago.[iii]  Essentially, we are not so genetically different from people that lived 50,000 years ago and probably earlier than that. 

Agriculture became prominent around 12,000 years ago allowing humans to do things other than hunt and gather food.[iv]  Agriculture created food surplus and security paving the way for modern human civilizations.  Farming has become so efficient that very few humans have anything to do with the production of the food they eat.  This is not a bad thing because it freed up a lot of time for us.  All of the progress of the human race in the last 10000 years can be attributed to this newfound time to think with that rather large brain we have. 

So, humans that walked like us, looked like us and for the most part were like us genetically spent roughly 200,000 years hunting and gathering.  They likely walked great distances often carrying a child or food.  In current hunter-gatherer societies the average child is carried 1500 km in the first two years of its life![v]  Bending, squatting and stooping to collect seeds or other food from the ground would be common.  They would likely climb trees to acquire fruit and nuts.  The occasional run to catch or not be caught by something as well as lots of throwing rocks or spears to kill small and sometimes very large animals.  Evidence suggests that these nomadic humans would spend 3 or 4 nonconsecutive days a week hunting and gathering performing strenuous physical activity for much of the day, followed by a few days of rest and recovery.  During this time they would still be active erecting huts, preparing food, making tools and partaking in leisure activities such as vigorous play and ceremonial dancing[vi]

Lets try to make some sense of this in terms of caloric energy expenditure and intake.  Your typical late Paleolithic hunter-gatherer expended about 21.8 kcal/kg of body weight doing activities of daily living.  Today that number is 8.7 kcal/kg of body weight[vii]. That is a huge difference!  Pre-historic humans used almost three times the amount of energy relative to their body weight as we do.  To put that in context, the average 70 kg male would have to add a 15 km walk to his day to equal the energy expenditure of a typical hunter-gatherer[viii].

Unsurprisingly, these people were likely much more physically fit than the average person now.  We know this from studying current groups of humans that still practice a hunter-gatherer lifestyle.  Cardiovascular (CV) power measured by V02 max for these groups averages 50% greater than the average in industrialized societies (57.2 ml/kg/min vs. 37.2ml/kg/min).  A V02 max of 57.2 ml/kg/min is elite athlete territory!  Shockingly they were also way stronger than the average person is today, to the tune of 20%[ix]

That is our potential: 50% better CV fitness and 20% stronger muscles on average!  Imagine the societal benefits if everyone could attain these fitness numbers.  It’s safe to assume we would be spending less on health care to say the least.  I would imagine these people likely didn’t smoke and drink very much either, but that’s a conversation for a different day.  

It appears that humans have continued to evolve in more recent time (the last 12,000 years).  The ability to digest lactose from dairy products is one example of a post agriculture genetic variation[x].  Other recent adaptations in the human genome are often related to disease resistance[xi].  While we are likely still evolving in some ways, the rate of change in the way we live has greatly outpaced the rate at which we can adapt on a physiological level.  We are still hunter-gatherers deep down where it counts at the genetic level[xii].

There you go, no need to wonder whether you should be exercising or not.  Your body is capable of a level of physicality far beyond current averages.   As a car has been built to be driven, you have been built to exercise.  Just like a car, if you leave your body in the garage too long, it will seize up.   Understanding how our body works and why is the only way we will develop a better relationship with exercise and food.  Hope this helps!



[i] S.B. Eaton, S.B. Eaton.  An evolutionary perspective on human physical activity:  implications for health.  Comparative Biochemistry and Physiology Part A 136 (2003) 153–159.

[ii] Vigilant L, Stoneking M, HarpendingH, Hawkes K, Wilson A.C.  African Populations and the Evolution of Human Mitochondrial DNA

Science, New Series, Vol. 253, No. 5027. Sep. 27, 1991 pp. 1503-1507.

[iii] McBrearty S, Brooks A.S,  The revolution that wasn’t: a new interpretation of the origin of modern human behavior.  Journal of Human evolution.  39.  2000.  P. 453-563.

[iv] Barker, G.  The Agricultural Revolution in Prehistory: Why did Foragers become Farmers?  Oxford University Press.  New York.  2006.

[v] Cordain L.  Gotshall R.W.  Physical Activity, Energy Expenditure and Fitness:  An Evolutionary Perspective.  International Journal of Sports Medicine.  19.  1998.  328-335.

[vi] Eaton S.B. 2003.

[vii] Eaton S.B. 2003.

[viii] Cordain L.  Gotshall R.W. 1998.

[ix] Eaton S.B. 2003.

[x] Bersaglieri T.  Sabeti P.C.  Patterson N.  Vanderploeg T.  Schaffner S.F.  Drake J.A.  Rhodes M.  Reich D.E.  Hirschhorn J.N.  Genetic Signatures of Strong Recent Positive Selection at the Lactase Gene.  American Journal of Human Genetics.  74(6) June 2004.  1100-1120.

[xi] Stephens J.C.  Reich D.E.  Goldstein D.B.  Shin H.D.  Smith M.W. Carrington M.  Winkler C.  Huttley G.AAllikmets R.  Schriml L.  Gerrard B.  Malasky M.  Ramos M.D.  Morlot S.  Tzetis M.  Oddoux C.  Di Giovine F.S.  Nasioulas G.  Chandler D.  Aseev M.  Hanson M.  Kalaydjieva L.  Glavac D.  Gasparini P.  Kanavakis E.  Claustres M.  Kambouris M.  Ostrer H.  Duff G.  Baranov V.  Sibul H.  Metspalu A.  Goldman D.  Martin N.  Duffy D.  Schmidtke J.  Estivill X.  O’Brien S.J.  Dean M.  Dating the Origin of the CCR5-D32 AIDS-Resistance Allele by the Coalescence of Haplotypes.  American Journal of Human Genetics.  62.  1998.  1507-1515.

[xii] Eaton S.B.

So, you're a bit sore

This is one of those times of the year when people are either returning to their long lost exercise routines or trying to get active for the first time.  It may be clichéd but January is resolution time for a lot of people.  Hey whatever your motivation is I’m just glad you’re adding some more healthy behaviors to your life.  If that included some gym time or some running for the first time in a long time (or ever) you may be experiencing the phenomenon of Delayed Onset Muscle Soreness (DOMS).  DOMS has been known to end many fitness journeys before they even really get going.  It can be debilitating in terms of the pain and stiffness it can induce.  You likely had to take a few days off, which have turned into a week and consequently killed any momentum you had going in this exercise thing. 

            First lets learn about what DOMS is, knowledge is power!  The muscles in your body are accustomed to and adapted for the activities you normally do.  When you do something novel with your muscles such as lifting weights, a new stress is placed on them that they are not adapted for.  This new stress will cause microscopic damage to the cells of your muscles.  It is this damage that is most commonly believed to be the cause of DOMS[1].  These are like tiny injuries and all injuries lead to an inflammatory response involving swelling, heat, redness, altered function and pain.  Why would your body do this to you?  Well, this is a necessary and natural process that helps your muscles get bigger and stronger.  So while it seems like a bad thing at the time its actually a good thing as long as you are able to continue with your daily life while its happening.  The pain from DOMS usually peaks 48 to 72 hours post exercise[2].  The discomfort you feel while actually working out is not DOMS but generally the more discomfort you experience during a workout the worse your DOMS will be.  DOMS is most attributed to eccentric muscle contractions or very intense isometric contractions[3].  Eccentric contractions refer to movements where a load is placed on a muscle while it is lengthening.  Think the lowering part of a biceps curl.  Isometric contractions occur when a muscle contracts against a load but no movement occurs.  Think of holding that biceps curl at the midpoint as long as you can.  Running downhill places much more eccentric load on the muscles in your legs in comparison to running uphill, hence why you get more sore after running downhill than running uphill.  Increased repetitions and increased loads will increase the amount of damage done to muscles. 

            Now that you know why you’re so sore let’s talk about what you can do about it.  Unfortunately this is where the news isn’t so great.  Once you have a good case of DOMS going on there is very little evidence that any of the interventions normally prescribed have any real impact on levels of pain or duration of symptoms.  Studies done on ice water baths[4] and stretching[5] have shown no real impact on DOMS.  NSAID’s such as ibuprofen will reduce pain from DOMS for a period of time but will not decrease the length of symptoms and may negatively impact the necessary healing process that is the underlying cause of DOMS[6].  Low intensity exercise has been shown to decrease discomfort during the exercise and for a short period of time afterward but DOMS symptoms return a short time after[7].  Lastly, massage has been shown to decrease the swelling caused by DOMS thought to be partly responsible for the associated pain.  This aids recovery, as with any injury where swelling is present, significant reductions in pain seem to be transient however[8]

            So what can you do to ease this painful condition?  A certain amount of DOMS is probably unavoidable when beginning novel exercise routines, however it doesn’t have to be debilitating.  For resistance exercises, stick to one set of repetitions and don’t go to complete failure the first time you try an exercise.  Keep your exercise tempo moderate; mainly you don’t want to do really slow eccentric contractions at first.  For instance when doing a squat, don’t go too slow on the lowering part at first.  Once you are accustomed to the exercise you can start to play with long eccentrics as they do have a place in weight training.  If you are doing some running for the first time in a while or at all, make sure it’s on a flat surface or even uphill as opposed to downhill.  Downhill running will make you sore due to the increased eccentric loads placed on your muscles.  Essentially, take it easy for the first few workouts back.  The temptation is to get back into the gym with a fury.  A more moderate approach will allow you to get more work done in that first week than doing one hard workout and then not being able to move for 48-72 hours!

            Finally, if you have a raging case of DOMS and you want to feel better for a while, hop on a bike or elliptical for and easy cardio session.  You should start to sweat a bit but keep it to 20 minutes or so, it should feel fairly effortless.  You’ll be feeling a bit better now so do some very light stretching if you wish.  Now head to your favourite RMT and get a light effleurage massage (they will know what to do).  After that go for a long walk and stay moving as long as you want to feel better because as soon as you sit down your DOMS will come back until your muscles are healed.  Next time just take it easy for the first few workouts!


[1] https://www.acsm.org/docs/brochures/delayed-onset-muscle-soreness-(doms).pdf

[2] https://www.acsm.org/docs/brochures/delayed-onset-muscle-soreness-(doms).pdf

[3] https://www.acsm.org/docs/brochures/delayed-onset-muscle-soreness-(doms).pdf

[4] Gulick D.T. et al.  Various Treatment Techniques on Signs and Symptoms of Delayed Onset Muscle Soreness.  Journal of Athletic Training.  June 1996 P.  145-152.  31(2)

Sellwood K.L. et al.  Ice‐water immersion and delayed‐onset muscle soreness: a randomised controlled trial.  British Journal of Sports Medicine.

 June 2007 p.  392-397.  41(6)


[5]  Gulick D.T. et al.  Various Treatment Techniques on Signs and Symptoms of Delayed Onset Muscle Soreness.  Journal of Athletic Training.  June 1996 P.  145-152.  31(2)


[6] Gulick D.T. et al.  Various Treatment Techniques on Signs and Symptoms of Delayed Onset Muscle Soreness.  Journal of Athletic Training.  June 1996 P.  145-152.  31(2)


[7] Gulick D.T. et al.  Various Treatment Techniques on Signs and Symptoms of Delayed Onset Muscle Soreness.  Journal of Athletic Training.  June 1996 P.  145-152.  31(2)


[8] Ernst, E.  Does post-exercise massage treatment reduce delayed onset muscle soreness? A systematic review.  British Journal of Sports Medicine.  1998 p. 212-214.  32.