What pace do you need to hit your marathon goal?

VDOT is a running fitness metric developed by coach Jack Daniels. You calculate it from a recent race time, then use the number to prescribe training pace zones: Easy (recovery and long runs), Marathon (goal marathon pace), Threshold (comfortably hard), Interval (hard 3-5 minute efforts), and Repetition (fast short sprints). For example, a VDOT of 40 (approximately a 3:50 marathon) prescribes an easy pace of 10:00-10:48/mile and a threshold pace of 7:52/mile.

The Riegel formula suggests multiplying your half marathon time by approximately 2.09-2.11 to predict marathon time. For example, a 1:50 half marathon predicts approximately a 3:51 marathon. However, this assumes equivalent training for both distances. Runners who have not done sufficient marathon-specific long runs (20+ miles) often end up 5-15% slower than Riegel predicts. First-time marathoners should add 5-10% as a buffer.

A 4-hour marathon requires an average pace of 9:09 per mile (5:41 per km). Over 26.2 miles, each mile must take just over nine minutes on even splits. A conservative strategy is to run the first half slightly slower (9:15-9:20/mile) and aim for a negative split in the second half. This requires discipline at mile 1 when adrenaline pushes you faster, but it dramatically reduces the risk of hitting the wall. A 4:00 finish places you at approximately the 45th percentile of male marathon finishers. Source: RunRepeat 2023.

VDOT is a running fitness metric developed by coach Jack Daniels, loosely correlated with VO2 max but adjusted for running economy. You calculate VDOT by entering a recent race time. The number then maps to five training pace zones: Easy, Marathon, Threshold, Interval, and Repetition. For example, a VDOT of 40 (approximately a 3:50 marathon) prescribes an easy pace of 10:00-10:48/mile and a threshold pace of 7:52/mile. Training at the right paces is critical: running easy days too fast is the most common mistake recreational runners make. Source: Daniels, Daniels' Running Formula, 3rd Edition.

A negative split means running the second half of a race faster than the first. Research and elite racing patterns both support this approach. The physiological rationale is straightforward: starting conservatively preserves glycogen and delays fatigue, allowing you to maintain or increase pace when most runners are slowing down. A 2-3% negative split (about 2-4 minutes faster in the second half for a 4-hour marathoner) is realistic and effective. In practice, negative splitting requires significant discipline because early miles feel easy and the temptation to bank time is strong. Source: Abbiss and Laursen 2008, Sports Medicine.

The Riegel formula suggests multiplying your half marathon time by approximately 2.09-2.11 to predict marathon time. A 1:50 half marathon predicts approximately a 3:51 marathon. However, this assumes equivalent training for both distances. Many runners who are well-trained for a half have not done sufficient marathon-specific long runs (20+ miles), and their marathon ends up 5-15% slower than Riegel predicts. First-time marathoners should add 5-10% to the Riegel prediction as a buffer. Source: Riegel 1981, Vickers and Vertosick 2016.

To convert min/mile to min/km, divide by 1.609. To convert min/km to min/mile, multiply by 1.609. For example, 9:00/mile = 9:00 / 1.609 = 5:35/km. And 5:00/km = 5:00 x 1.609 = 8:03/mile. For treadmill users, speed in mph converts to pace as follows: pace (min/mile) = 60 / speed. So 7.0 mph = 60/7 = 8:34/mile. Knowing both conversions helps when following international training plans or comparing times with runners in other countries. Source: standard unit conversion.

As a general guideline, runners should consume 30-60 grams of carbohydrate per hour during a marathon, starting from approximately 45 minutes in. Common fuelling options include energy gels (20-25g carbs each, taken every 30-45 minutes), sports drinks, and chews. Water and electrolyte intake should complement carbohydrate intake: aim for roughly 400-800ml per hour, adjusted for sweat rate and temperature. Practise your fuelling strategy on long training runs, as gastrointestinal distress is the most common nutrition-related issue on race day. Never try a new product on race day. Source: Jeukendrup 2014, Sports Medicine; ACSM position stand.