Race pace. Training pace. Calories per mile. How much hot days slow you down.
Over the years I've learned a number of rules of thumb about running marathons, covering everything from the impact of weight on performance to how running marathons impacts age and how age impacts running marathons. What follows are the rules of thumb that seem to matter most and ring most true.
Taper and Race Day Rules of Thumb
- Taper your training so that you run no more than 85, 75, and 50 percent of your maximum mileage the three weeks before the marathon, respectively
- Never try anything during a marathon that you haven't tried in practice runs (eating Gu, drinking a sports drink, wearing different socks, shoes or shirts, etc.)
- Drink about 4 ounces of fluid per mile
Basic Race Pace
- Calculate marathon finishing time as 2x a recent half marathon race + 6 to 10 minutes, go here for a simple minutes per mile pace calculator or use these rules of thumb
- A 7 minute mile pace puts you just above 3 hours (6:51 to break 3 hours)
- An 8 minute mile pace gets you under 3:30 for the marathon (8:00 to break 3:30)
- A 9 minute mile pace puts you comfortably under 4 hours (9:09 to break 4 hours)
- A 10 minute mile pace gets you in under 4:30 (10:17 to break 4:30)
- Run an all-out mile after a warmup and multiple by 1.3 to get your minutes per mile pace
- When you're within a month of the race, enter ANY race time to see a better approximation of your expected marathon time than any rule of thumb provides using the fabulous McMillan race calculator
Environmental Factors That Impact Race Pace
Many factors will impact the above calculations, including going out too fast, heat, and humidity
- Always run the first half a little slower than the second (negative spits)
Running negative splits doesn't mean your pace won't still hurt at the end, but it hurts a lot less than going out too fast with splits like the 1:40/2:13 I ran at the 2007 LA Marathon, which leads to this rule of thumb:
- Each minute too fast in the first half will cost you four minutes in the second half
Based on this rule of thumb, I should have gone out 7 minutes slower (1:47) to gain 28 minutes in the second half split (i.e., 1:45) for a 3:32, a net improvement of 21 minutes.
- Add 2% to your time for every 5 degrees warmer between 60 and 75F, then double that impact for each additional 5 degrees up to 85. Running guru Jeff Galloway puts it this way:
- 55-60 degrees - 1% - 8:00 becomes 8:05
- 60-65 degrees - 3% - 8:00 becomes 8:15
- 65-70 degrees - 5% - 8:00 becomes 8:25
- 70-75 degrees - 7% - 8:00 becomes 8:35
- 75-80 degrees - 12% - 8:00 becomes 8:58
- 80-85 degrees - 20% - 8:00 becomes 9:35
- Above 85 degrees - Forget it ... run for fun and not time
- Add 1 second per mile for every percentage point the relative humidity exceeds 65%
- Follow this link to the full-blown Max Jones formula for calculation of marathon finish time based on weight, age, temperature, and 7 other factors
I like the Furman plan for marathon training because it is based on doing each run for a purpose, running fewer miles faster, and cross-training for greater fitness and lower incidence of injury. Rather than the long-slow run regiment that advocates running everything at a pace 1 minutes 30 seconds slower than your marathon goal pace, Furman has you mix things up with longs runs (faster than most plans suggest), tempo runs, and speed work. The basic purposes and training paces according to Furman are:
- Long Run at 10-K pace + 60 to 75 seconds/mile
- 7 to 10 mile tempo runs at 10-K + 30 to 35 seconds
- 4 to 6 mile tempo runs at 10-K + 15 to 20 seconds
- 3 mile temp0 runs at 10-K pace
- 1600m repeats at 10-K - 35 to 40 seconds
- 1200m repeats 10-K - 40 to 45 seconds
- 800m repeats 10-K - 45 to 50 seconds
- 400m Repeats 10-K - 55 to 60 seconds
Many people run to control their weight. The rules of thumb that matter are:
- You burn roughly 100 calories per mile
- You must burn 3500 calories to lose a pound
Thus if you run 35 miles a week without consuming more calories than you did when you weren't running, you'll lose a pound a week.
To maintain energy available to your muscles while training, follow this rule of thumb:
- Consume about 300 carbohydrate calories immediately after running to replenish glycogen stores.
We could argue for awhile about the actual calories burned per mile, which is impacted about 20 percent based on speed, but the really important thing about weight and running marathons is this:
- You'll add 2 seconds a mile or 1 minute a marathon for every pound over your ideal weight
Some misguided souls (and the Nintendo Wii Fit) point you to BMI as a measure of ideal weight, which you can actually calculate by yourself with this formula
- BMI = ([weight in pounds x 703] divided by [your height in inches squared])
although most people use online calculators (or a Wii Fit). I won't point you to such calculators so you'll keep reading and use something better than BMI.
For reasons I explain in BMI is Brain Dead, use this Ideal Weight Calculator instead. The calculation is difficult to melt down into a rule of thumb, but the bottom line is that the Ideal Weight Calculator is better than BMI because it considers your gender and frame types to more accurately calculate ideal weight. The rule of thumb for frame types is:
- Wrap your thumb and major fingers around the smallest part of your wrist and you have a:
- Small Frame if the fingers overlap
- Medium Frame if the fingers barely touch
- Large Frame if the fingers don't touch
Age and Marathon Performance. There is no doubt that age impacts marathon performance. Lots of reasons for this, including a steady decrease in VO2Max, flexibility, and susceptibility to injury. Here are some basic rules of thumb:
- Your maximum heart rate slows about 1 beat per year (causing commensurate decrease in VO2Max)
- Best marathon times slow 1 minute or more a year past your mid- to late thirties.
This rule of thumb does not hold for people who take up running seriously later in life, who will find that they'll improve during their first few years of running marathons as progressively better conditioning masks the effects of aging. Eventually, everyone faces the following:
- Runners who remain highly fit can expect a decrease in performance of 1/2 to 1 percent a year (with 1/2 percent corresponding to roughly 1 minute for a 3-hour marathoner)
Fighting off the Impact of Age. There are two ways to look at the subject of age: how you can beat the impact of age on your general well being by running, or what you can do to minimize the impact of age on your marathon times.
I'll start with running and well being which come from this study by Stanford.
- Runner's initial inability to fully care for themselves comes 16 years later than non-runners
- Elderly runners do not have higher rates of osteoarthritis or knee replacements than non-runners
- In a 20 year study of people over 50, more than twice as many non-runners had died (34 percent) than runners (15 percent)
While it's fabulous that running fights off the effects of aging, what can you do to minimize the impact of aging on marathon times? Few can maintain the same level of training after 50, so consider:
- Less frequent training with lower volume, but maintain intensity
- Cross training
- Weight training
- Careful stretching to maintain flexibility and reduce incidence of injury
- Maintaining your ideal body weight
- Shifting the way you judge your marathon times to age-graded time calculations and achievement percentiles
While the calculation is hard to put into a rule of thumb, it's essentially seeing where you stand against others your age. For example, my 3:20 at age 54 was an age-graded 2:56 based on a 71.75 percentile ranking against my age group's record.
- Take 1 day off to recover for each mile you race, or roughly 4 weeks after a marathon
- Alternatively, run easily as it feels okay to do so, putting in roughly 10 miles of easy running for each mile raced before you're fully recovered
I'm sure there are other rules of thumb covering different aspects of marathoning that I've not learned, plus some that deal better with various concerns than the rules of thumbs I've learned do, and I'd love to hear about them. Please comment below.