Runners like to measure themselves. Be it miles run, calories burned, weight gained or lost, pace, heart rate there a lot to choose from. And it seems new, "important" numbers pop up as fast as we can write them down, such as lactate thresholds or muscle fibre type. Some runners log their miles while others track their minutes. In addition, should one simultaneously track their resting and maximum heart rate? What about pace, calories burned, or bodyweight? How to choose? It's clear enough the dedicated athlete maximizes his or her information, but even the most data-oriented individuals can fall under the weight of numbers.
Compiling these metrics is not intended to clarify or rank them. What I'm hoping in gathering as many as I can is illuminating just what people consider, and is available, to measure. And it is rare to find comprehensives lists of these metrics. Therefore my main goal was to find 51 "measurable" things related to running that have been used, or recommended, by a credible source.
I present these findings in no particular order of importance, but accompanied with a brief commentary. I expect most of these metrics are familiar to almost everyone, some that only known the seasoned veterans, and a few that are relatively unknown. I've broken the list into 8 categories: Milage, Body, Shoes, Rest, Diet, Strength, Workouts, and Races.
One final warning: When including new metrics in one's melting pot pick and choose carefully. Monitoring all these variables at once is not a healthy way to train!
Mileage stats
2. Altitude: Though a contentious measure in terms of training, it is a fact that altitude affects your running. This much is hard to debate: the greater the elevation, the less oxygen to breathe, and slower you will run mid-to-long distances. Jack Daniels wrote his PhD on this very subject. Mind you, if you are a sprinter the greater altitude means thinner air, lower air density and thus faster times. Be it for training, racing, or resting, runners are seldom unaware what altitude they currently reside.
3. Miles or minutes run per year (or season): This measure can only be known by those who log all their weekly volume stats. And unlike weekly volume, a neophyte athlete expects this value to consistently rise from year to year. Even seasoned athletes, especially those training for marathons, will attempt to increase this years' seasonal volume over last.
4. Distance of longest run: In the mind of a runner the Sunday long run occupies a special place in their psyche. Separate from other days, the Sunday long run is its own ritual. Though loosely related to marathon training, shorter distance runners keep track of this run too. It is perhaps the most accurately measured -and planned for- of any run. As I write this (on a Saturday), I know exactly (within a mile) how far several of my peers are running tomorrow. The same could not be said for any other day.
5. Number of runs per week: After returning from a summer's base building, a character in "Running with the Buffaloes" brags that he averaged 90 miles a week "all in singles". For a given volume it is mportant to many is how many runs it took him or her to achieve it. Ten runs a week of 10 miles each is not the same as eight runs of 12.5 miles.
6. Easy run pace: Most of one's running volume is done at an easy, relaxed pace. It can turn into an obsession how fast this easy pace is run. Are 7 minute miles too quick or too slow? Do 8-minute miles mean junk milage? The debate is far from over, but for my money the issue of easy pace is red herring. Obsession over the easy pace may negatively influence whether choosing mileage or time as a metric, after all D = Vt. Bottom line is that one's easy pace should feel easy. Still, one may insist, what pace is that? That I cannot say.
Body numbers
7. Age: Everyone knows their age, but in terms of running it can translate into asking "how many years of competitive running do I have left?" or the related "am I too old/young to start training seriously?". There is no "wrong" age to start running, but it is true world records are set by those in their mid 20s to mid 30s. For anyone trying to best themselves, the inexorable march of time makes their present age matter a great deal.
8. BMI (body mass index). The BMI is a function of height and weight. Loosely speaking, your BMI tells you if you're fat, skinny, or "just right". In the real world this number is of little importance since the only true variable is your weight. The BMI does however help reorient athletes with unfounded fears of being "too fat" (especially girls).
9. Resting heart rate: Pop quiz: do you measure you resting heart rate sitting, standing, lying down, just before going to sleep, or waking up? It turns out all those qualifiers can affect your RHR. It also matters whether you are aware someone is measuring your pulse, holding your breath, or thinking about exciting or boring things. I proved this to a friend by raising and lowering my RHR by 10 bpm without any visible action. Don't sweat this one.
10. Maximum heart rate: Growing up, my local swimming pool displayed a chart for expected MHRs by age and sex. Though I have measured many attributes, I still don't know what mine is. Probably in the 180s. But since your MHR is hard to change and varies widely even for top athletes it's used more for workouts that involve %MHR (i.e. tempo at 70%, easy at 50% etc). I say use with caution.
11. Heart rate reserve: If you subtract your resting heart rate from its maximum, you get the HRR, where HRR = MHR - RHR. This variable is claimed to show your fitness potential, i.e. gives your more room to play. But the RHR is hard to pin down and worse yet many race paces such as sprinting go into zones at which the MHR has already peaked. Despite its alluring potential, I would be just as cautious about this yardstick.
12. Body fat percentage: Bodyfat is hard to pin down accurately. One can purchase scales for home use that give rough estimates but a full body scanner or water tank is necessary to know for sure. Once known, this variable is difficult to interpret. Men have lower BF%s than women, but the absolute numbers differ by sport and distance. As with the BMI, bodyfat manipulation should be avoided if you are otherwise a healthy person.
13. Fast/slow-twitch muscle percentage: There are three types of muscles: Type I, type IIa and IIb. The first is slow twitch, while the latter two are fast twitch. To know for sure what you have in those legs/arms/whatnot you need a muscle biopsy (which I've heard are painful). Because these percentages change little over a lifetime, runners may fret that they have the "wrong" fraction. But recall, the total always adds up to 100%. Therefore your personal allocation is perfect for some distance.
14. VO2max: The maximum uptake of oxygen by the body is what it is, and measured by running on a treadmill while monitoring oxygen intake versus exhalation. The 1990s was the decade of the VO2max. It has not been so prominent before or since. Thank goodness for that. For a time, it was theorized, that if you improved this measure you would improve your racing speed. Supposedly the magic bullet to training we soon learned the VO2max was hard to manipulate (not least at the cost of other metrics). And as the statistics aggregated it was found poorly correlated to actual running performance and the house of cards began to fall. The VO2max is real enough, but its relevance to ultimate running performance is dubious at best.
15. Lactate threshold: Shortly after the previous measure was marginalized, the lactate threshold began to emerge. This measure requires taking small blood samples from an athlete who has recently completed a workout (often by a pinprick on the earlobe). The results are reported as mmol lactate per kg blood. Good runners were found to have higher thresholds, and the threshold workout became by definition the maximum pace at which lactate ions would remain in equilibrium. This value is more useful than VO2max because it more directly responds to training stimuli. But how many of us take blood samples during our weekly workouts?
16. BMR (basal metabolic rate): Each of us has a different BMR, defined as the calories consumed while doing nothing active. When someone says they have a high metabolism it means their BMR is high. This metric can depend on diet, bodyfat, and eating habits. It is important when estimating your daily calorie consumption not to neglect your BMR. I personally have no idea what my BMR is.
17. Foot ground-contact time: Ground contact time is important for sprinters and studies measuring foot impact forces, such as Lieberman's famous Nature article on barefoot running. Some coaches may advice their athletes to achieve light, quick, footsteps while running, but I have discussed in an earlier post that it is not a mission unto itself to minimize ground contact time.
18. Pain: Though subjective, pain influences our day-to-day or second-by-second decisions while exercising. Doctors routinely ask patients to rate their pain scale on a scale of 1 to 10. Because of the near universality of the question and pain's translation into numbers it seems to deserve a place on this list.
19. Blood glycogen levels: Diabetics are extremely aware of this number, but so are some sport scientists, doctors, and curious souls. Low glycogen during an ultra marathon can lead to sudden fatigue. For extreme distances where your body fat may be consumed in non-trivial amounts, or for the health conscious (in particular over or underweight individuals), this variable could matter a great deal.
Shoe measures
20. Mileage on shoes: Separate from your body's mileage is how many miles your shoes have travelled. Salespersons have it drilled into them to remind customers their shoes should be replaced after 5 or 6 hundred miles. I know of no credible (or incredible) research that has discussed this claim in detail. Pro athletes are of no help because new shoes arrive at their doorstep every month. Nevertheless, ask many a recreational runner and they will tell you about their shoe's age or miles like it was a car.
21. Weight of shoes: Companies often advertise the weight of their shoes. Lighter is better. Once upon a time cushioning was all the rage, but seldom does NewBalance fail to report how many ounces their (size 9) shoe tips the scales. Nike's new Flyknit weighs just 1.2 ounces.
22. Toe-to-heel differential: The unresolved debate between cushioning and lightness created this additional variable, where the difference between the heel and toe shoe foam thickness is taken and interpreted as a gradient. A "zero-drop" shoe is one where the gradient is flat. More information can be found here.
23. Length of spikes: Though irrelevant to the recreational runner, cross country and T&F athletes alike know exactly how long each of their shoe spikes is, perhaps to obsessive degree (I'll confess I was one of them). Muddy and rain? Better get out the monster 15mm's. Indoor track meet with banked turns? The 5's will do just fine.
Rest, quantified
24. Hours of sleep per night: One of the most underrated metrics in rest is much much sleep you get. There are the extreme cases like Mary Keitany, who I've heard get 12 hours sleep a night, to Dean Karnazes, who claims a mere 4. "Typical" athletes need between 8 and 9.
25. Rest days : Related to total runs per week, some people like to count how many rest days they get every week. Read many a training manual and will likely say no more than 4, and no less than 1 (though rest for some still means running, just less).
26. Consecutive days running: More like the opposite of a rest day, runners call this streaking. For some, the goal is to track how many days in a row they have run. Numbers can get impressive, like Mark Covert, who has run for 16,000 days in a row.
Diet metrics
27. Total calories consumed (per day): The most obvious of the diet elements to track, but harder than it first appears. Not all labels are accurate, and knowing your BMR is an important detail. Coached like Wetmore supposedly like giving runners 1500 calorie diets to thin out. Personally I like eating until I'm full.
28. Percentage of fat or protein in diet: If unsatisfied with tracking total calories, some want to know if they're getting enough protein or fat, or too many carbs. The book Racing Weight by Fitzgerald spends significant time on this topic. People like Time Noakes advocate a high fat diet, and has even led to vigorous debates on the subject.
29. Number of meals per day: This variable sounds made up, but there are serious debates about this too. Some will refer to a grazing diet, which implies many meals per day, whereas others consider the occasional "starvation" to be beneficial. In reality these are two sides of the same coin: starvation for 12 sedentary hours is equivalent to 2 hours of running while not eating. Simple as that.
30. Vitamins & minerals: Measured as a percentage of RDI consumed, athletes will try to deliberately overdose the B and C vitamins, which are water soluble and associated with more energy and health. Check the label of Greens Plus or a Mega Man vitamin and you find many times the recommended intake for each. No quality research has ever supported mega doses of vitamins, but that won't stop people from trying.
31. Time since last meal to sleep/before race: This sound like a trivial measure until you're an hour from a race start and your stomach won't settle. I admit I remain timid about eating much before a race, will will keep careful watch of the hours until the start.
32. Money spent on food each week: This is not a true measure of exercise, but since food is a never-ending expense it warrants examination. For instance, can you eat a healthy 3000 calorie diet while spending less than $100/week on groceries? I would argue yes, but that's a whole other article.
Strength and speed by the numbers
33. Max repetition weight: Once in the gym, the urge is to find yet more things to measure. The easiest is a 1 max rep, usually in the form of squats or deadlifts, but other means will do. Keith Livingstone, a sub 30 min 10k runner and author of Healthy Intelligent Training says his max squat is 300 lbs. What's your number?
34. Max number of reps: It seems fair to lump all ushups/pull-ups, etc together. These include maximum number of chin-ups, pushups, sit-ups, or similar activities. Runners need strength training too, and this is one way to measure it.
35. Reaction time: Not a distance runner's concern, but any sprinter is sure to know his or her reaction time. For instance typical reaction times range between 0.14 and 0.21 seconds.
36. Sprint time (50-200m): Now and then runners of all distances practise their sprints and may even know their times. While some distance coaches consider these times unimportant, others like Alberto Salazar consider it the foundation for speed at longer distances.
Workouts variables
37. "Yasso" 800s: The theory goes that if you can run a set of 800 meter repeats in Y min, X seconds you'll be able to run a marathon in Y hours and X minutes. Like all running rituals there's an element of truth but I wouldn't get too excited by these. There is no such thing as a magic workout.
38. Speed volume: Am I repeating item number ? Not quite, for speed volume is technically separate from total volume, and is measured by taking the ratio of the two. For instance if you combine all your speed and up-tempo running together, it should constitute between 10-15% of the total. Hence this too it would appears needs tracking.
39. Number of sets: You've decided on running Yasso 800s, or mile repeats, or 400s. Now how many will you do? This is that number.
40. Rest between sets: You've decided on the set distance and number, but running 1k repeats with a minute rest is not the same as with five. Choose wisely.
41. Number of workouts per week: Runners do between zero and three workouts per week. Though the range is small, over time it can matter.
42. Breathing rhythm: I had never heard of breathing rates until reading Jack Daniels training book, but he found some athletes take more steps per breath. Some take one step breathing in, and two steps breathing out, while others take three steps for breathing both in and out. My advice: ignore this number! It will confuse the heck out you the more you think about it. Believe me, I tried.
43. Cadence (steps per minute): Another variable courtesy of Jack Daniels, who noticed most athletes run about 180 steps per minute. This is an oversimplification, as many experienced runners run at many cadences, and it depends on their speed and height. I do not recommend spending much time on thinking about this as it might only distress if your cadence is "optimal".
44. Duration (weeks) of peaking phase: An abstract variable, but important nonetheless. I find that I can only handle six weeks of intense, continuous training before I peak, then burn out for the season. Usually this "peaking phase" lasts anywhere from 4 to 10 weeks, but it's a number many a racer are sure to know.
45. Strides/hill sprints number/frequency: In his book Run Faster, Brad Hudson tasks the reader to specifically track his or her number of hill sprints, usually between 1 and 12. These he considers separate from other workout variables, as they peak in number early in the training season.
Race digits
46. Marathon race time: I wanted to write "race" time, but I opted for marathon time as it falls into a special category. In particular not matter how many workouts you do, you never really can tell how a marathon will pan out.
47. Length of taper (before "race day"): Most claim a two week taper is best, for some a week, others up to a month, and a rare few claim not to taper at all. I find about 10 days is good for me.
48. Years spent "competing": This metric is less related to your age. Brad Hudson estimates anyone beginning to race will not peak for a number of years. Therefore a 50 year old newbie will have a good 10 years at least to improve, and so on. Many senior world records come from late comers to the sport, another reason it's never too late to start.
49. Hours awake/asleep before race: A minor detail perhaps, but everyone has an optimal time they wake up before a race. Some maximize their sleep while others make sure to wake up a minimum two hours before race start. If you don't like this one, substitute it with "duration of warmup before race".
50. Age-graded race time: A recent addition to some race results, it takes the % of anyone's time compared with their respective age/sex world records. In this way anyone of any age can compete with top level Kenyans. Interestingly, I've noticed the young elite usually end up on top anyway. Training always matters.
51. Riegel numbers: Here's the variable no-one has heard of. I had a hand in developing it, and consists of two values I call m and k, the input is all your race times. But it's worth considering, as it may reveal how fast you fatigue for long distances.
Others: In case you thought the above list was exhaustive, here's a few more to whet you appetite: Wind speed, hill gradients, ground-foot impact forces (in G's), stride length, galvanic skin response, water weight lost per during workouts (i.e. sweat), lung volume, negative/positive race split difference, and even ice bath time (minutes).
Final thoughts
When I began to train more seriously, my personal inclination had been to write as much information down as possible. I made it a goal to log all the information I could. Then I got tired of writing down so much detail every day as I found it did not advance my goals as a runner. So I swung the other direction and wrote nothing down. Now I'm somewhere in between; remembering some numbers while forgetting others. Think of it like chess where the best players know as much about what to monitor as what to ignore. The absence of any mental "pruning" is why computers used to play lousy chess. So every day I choose of difference set of running variables to be important. And it kind of works. No one said using metrics would be easy.
