5km march in Roman armour: the numbers are in.

In May of this year I donned the Roman armour for the charity Rise UK and marched, or more accurately waddled, 5km (my JustGiving page is here). In thie piece I’ll be sharing my experiences of it as well as some interesting data (to some at least!) I’ll also be dropping a podcast soon all about this and giving an overview of the Marian reforms so check my site and twitter (@ancientblogger) for updates.

In the pic below you can see yours truly complete with non-regulation caligae, if you watched my brief vlog on the preparations for the upcoming 5km this will not be a surprise for you.  I don’t own any caligae and to wear a fresh pair on a 5km march on a hard surface would merely serve to make local physios far richer. I also omitted to take my pilum and gladius, of the former I can only say that carrying a long piece of wood with pointy ends in an event where people are running past you is best left for the screenwriters of the next Final Destination to drool over. The gladius was also a practical decision, yet it also felt inappropriate where I was representing a charity involved in supporting victims of domestic abuse.

The remaining lorica segmentata, helmet, belt and scutum came in at around 19kg, so I was still relatively encumbered, but it wasn’t really the weight which made the march a tricky affair.

The scutum is an iconic shield and if you want to learn more take a look at my vlog on it. What I didn’t cover in said vlog was what I referred to as the ‘Mary Poppins Effect’, whereby the sheild acts like an umbrella. Simply put it picks up the slightest breeze – if this is going across you and onto the scutum you aren’t allowed the luxury of it hanging on your arm as much. Instead you push back which quite fatigues the arm and shoulder. The reverse is true if the breeze is coming across you the other way and toward in inside of it. The scutum then decides it wants to play umbrella and pull across from you.

Poppins: no known association with the Roman military complex

I had the pleasure of this experience throughout the march and discovered that it was easier to have the breeze carry the shield away from you (so imagine it is in your left hand the and wind direction is coming from your right). With no optio or centurion to shout at me I indulged in swapping sides to keep my arm less numb.

1st century AD problems indeed.

I found the march hard going, my shoulders and lower back certainly a testament to the event on the following Monday morning. That said, an hour of deep tissue massage the next day (where I was introduced to the horrific delights of trigger points) lessened the duration of my Tin Man impersonation.

The Science Bit

Throughout the march I’d worn my Fitbit so I could capture some crude data and a few weeks later I walked the exact same route sans armour to give an idea of the effect on my body. In terms of time there wasn’t much difference.

Without armour: 55 mins 44 seconds

With armour: 58 mins 31 seconds

In armour I was moving at a very respectable 3.2 mph, Steven Kaye (who we will be reading much more from) estimated that the average speed for a legionary on a flat Roman road was 2.85 mph. However, I was travelling with around half the weight a 1st century AD legionary might be expected to carry which goes a little way to explain the disparity (fitness levels and age going the rest of it!)

The real story of how my body managed the situation can be seen in the heart rates:

without armour (left) and with armour (right)

One of the idiosyncrasies I have discovered with my Fitbit is that it doesn’t like to be fastened too tight on my wrist otherwise it results an unusually high reading. I spotted this early on so you can take the initially high heart rate reading out when looking at B. As you might imagine my heart rate was consistently high when moving with the armour, around 140 bpm. If we take the outlier from when I did it without the armour my average comparable heart rate was around 105bpm.

The discovery that moving with armour is harder than doing the same activity without isn’t revelatory, what is interesting is just how much. This reflected in the calories burnt.

without armour (left) and with armour (right)

There was only 60 or so calorie burn difference between the two, but taking into effect the unreliable HR reading I mentioned earlier (seen in the peak of the second graph) we can guestimate a difference of around 150 calories.

Needless to say I’d need a much larger data set (and more willing participants) to draw any substantial conclusions, and that’s before you factor in, pun intended, that I’m no spring mule. Without more substantial data you may feel that there’s little we can truly understand about how Romans marched and what the effects were, but this little piece of pseudo science does make for interesting basic analyses and actually led me onto finding someone who has done much more besides. When researching information about Legionary marching I stumbled upon a paper by Steven Kaye titled “Observations on marching Roman legionaries: velocities, energy expenditure, column formation and distances”. To say that it’s in depth would be an understatement, data drips from the pages and it’s certainly worth a read if that’s your bag (or even if you have just a passing interest in the topic). Kaye works on the premise of a legion (or legionary) marching 29km on a flat Roman road in August and building a basic camp at the end of it.

Along with the sumptuous data there are some very interesting snippets; for example it would take an entire legion 1hr 22 minutes to all march past a specific point. Kaye also looks at all the logistical aspects of moving a body of around 5,000 men and supplies to another locations. Energy expenditure is calculated per legionary (even down to legionary weight) and based on the assumption that the legionary carried around 40kg in kit.

All the information I use is found in his paper, but to summarise in the context of how hard a legionary worked just on the march alone – Kaye calculated that a legionary of around my weight (90kg) would expend 3,288 kcals over the course of the march (which would last 7hrs 22 minutes). As mentioned weight of the legionary was taken into consideration, a much lighter legionary (60kg) might expend 2,777 kcals. This figure also took fatigue of the legionary into account.

But a legionary’s work wouldn’t end there. Assuming the legion arrived at the new location (which would have been previously scouted) a basic camp would need to be constructed. The most arduous task would have been digging the ditches and building ramparts. Again, Kaye factored in this activity and you can see the totals in the table below:

Kaye’s paper underlines just how much logistical thought had to go into supporting the army. It’s not just about having the right amount of supplies, if you want to move 5,000 men in an orderly fashion this needs tight discipline and organisation. Kaye scoped out what might be the daily routine of a legionary (weighting 80 kg) and though it’s slightly off the track I feel the content is interesting enough to share here.


It’s fair to say that after my 5km march, one sixth of what the legionaries in Kaye’s paper faced, I was of little use to man or beast and spent the rest of the day with my feet up. But again, I’m a 40 something office worker, about as far from a lithe Roman legionary as you can get.

I’m unsure if I will do it next year, it’s great fun and any reason to don the lorica is a good one. Perhaps I might try it with the scutum on my back (as they were apparently carried) alternatively if I can get hold of some lorica hamata it would be a good opportunity to contrast it to the segmentata. In either case I’ve got plenty of time to think it over.








2 thoughts on “5km march in Roman armour: the numbers are in.

  1. Ben Kane

    Well done!
    I have marched more than 500 miles/800km in full kit, including Hadrian’s Wall. Avg. daily march 16-20 miles. The only practical way to carry the shield over such distances is on one’s back. Every single reenactor I know who has marched similar distances found the same. Once you learn how, the shield is easy to don and remove, and can be in one’s fist, ready to fight as it were, in less than 20 seconds.

  2. ancientblogger Post author

    I did fancy giving that a go and have read that’s how they carried the shield. I wondered about how easy it would be to equip so that’s very interesting to know. Thanks!

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