Suboptimal Conditions

Suboptimal Conditions

Racing and Training in Suboptimal Conditions. In a perfect world, we wouldn’t have ideal conditions when we set out to run a PR or even attempt a major workout. In this scenario we would be looking at 40-50 degrees Fahrenheit temperature, low humidity, and no wind. In addition, a PR attempt should always take place at sea level or at least somewhere at 2000 ft elevation or lower. While we can try to select goal races that historically have good conditions, race day weather is unpredictable and it’s not always possible to run workouts in ideal weather due to non-running commitments in our life. What do we do when we toe the starting line of our race or workout and it’s 75 degrees out, 100% humidity, with a moderate 15-20 mph wind for good measure? While it’s disappointing to know we won’t run our fastest that day, we can still adjust our goal pace to run as fast as possible and be competitive. Below we will go through the impact of these factors and how one should adjust their pace to deal with them.


You’ve picked out a goal race, had the best training block of your life, and the taper goes as well as one could expect. Then you get to the race and are met with historically warm temperature. What now? As it gets warmer out, our body diverts blood away from our muscles to our skin to cool down. Since running is a highly aerobic sport, the lack of blood equates to less oxygen we can use to keep running at the same speed.

A great online resource to estimate your adjustment is the Jack Daniels RunSmart Calculator ( Using 2:30 and 3:30 marathoners as examples we can see their projected marathon pace at various temperatures.

59°F / 15°C or cooler – 5:43 / 8:00
60°F / 16°C – 5:44 / 8:01
65°F / 18°C – 5:46 / 8:05
70°F / 21°C – 5:49 / 8:09
75°F / 24°C – 5:52 / 8:12

We see that our runners start slowing down slightly when the temperature reaches 60 degrees. The slowdown is a percentage of pace and not the same for all runners – our 2:30 marathoner faced a slowdown of 2-3s/mi for every 5 degrees increase in temperature while the 3:30 marathoner lost about 3-4s/mi for the same rise in temperature. Also, the estimated impacts also assume you are fully acclimated. If you have been training somewhere cool and dry all winter and show up to Florida for the Gasparilla Classic or the Gate River Run, consider doubling what the calculator suggests.