Will you ever BQ? Data, age and what the science says

When Ben Mark stepped onto the start line at the 2019 Philadelphia Marathon, he was certain it had to be his day. He had finished a hard training block injury-free, run a 1:25 half marathon weeks earlier, and was about to become a father. The pace plan was a sub-3-hour finish, the time he needed to qualify for Boston. By mile 18, the 3-hour pace group was past him. He stepped off the course.

His story, told to RUN/Outside writer Ali Nolan in a data-heavy feature on Boston qualifying, is the kind of moment many recreational runners recognise. The Boston qualifying time, or BQ, is one of the most popular goals in road running and one of the hardest to actually hit. The question, after a decade of cutoff times getting steeper, is whether the math has changed permanently or whether age, training and biology still tell the same story they did a generation ago. Peer-reviewed research has a clearer answer than the anecdotes.

What the qualifying data looks like right now

Across roughly 564,000 finishers at 277 US marathons in the qualifying window for the 2025 Boston Marathon, only about 13 percent ran a time fast enough to meet their BQ standard, according to the RUN analysis. The split by gender was narrow: 14 percent of women hit their qualifying time and 13 percent of men did.

Hitting the published time is also no longer enough. Boston runs a finite number of time-qualifier slots, usually 22,000 to 24,000, and when more qualifiers apply than slots are available, the BAA cuts off entry by however many seconds it has to. That cutoff was around one to two minutes for most years after 2012. In 2019 it climbed to 4:52. By 2024 it was 5:29. For 2025 it reached 6:51, meaning a 40-year-old woman needed a 3:33 to actually get in, not the 3:40 the public standard suggested. The BAA tightened the qualifying times again for 2026, but RUN’s analysis projects the cutoff will still land near 5:29. More finishers, not slower runners, are driving the squeeze.

Where the science says the curve actually bends

Boston’s qualifying ladder bumps the standard by 5 or 10 minutes at each five-year age group, then by 20 minutes at age 60 under the 2026 standards. Those steps imply a fairly steady decline in marathon performance with each decade. The underlying physiology is more uneven.

A foundational 2008 review in the Journal of Physiology by Hirofumi Tanaka and Douglas R Seals pulled together data on masters endurance athletes and reached a specific conclusion. Peak endurance performance is generally maintained to about 35 years of age. Decreases through the 50s are modest. After 60 the decline steepens, and the curve bends down sharply after 70. The mechanisms are well mapped: a fall in maximal oxygen uptake, a drop in lactate threshold, and a decline in exercise economy.

The BAA chart partly tracks that shape. The flatness of the performance curve through the late 30s is why a 35-year-old gets only a small bump in their qualifying time. The ladder gets generous in a hurry, though. The published 10-minute jump between 44 and 45 runs ahead of what the physiology would predict for a still-training adult.

A more recent analysis is sharper on the role of training. A 2022 paper in the International Journal of Environmental Research and Public Health by Johannes Burtscher and colleagues pooled longitudinal data on masters endurance athletes and found per-decade VO2max declines ranging from 5 percent to 46 percent. The variation was not random. Changes in training volume explained 54 percent of the variance in men and 39 percent in women. Athletes who held training volume close to constant lost roughly 5 percent of VO2max per decade, about half the loss seen in untrained adults.

The flip side: when trained athletes stop training, the same paper found, VO2max falls almost linearly by up to 20 percent in 12 weeks, alongside drops in mitochondrial capacity. Most of that loss is recoverable with a similar period of retraining. What looks like ageing on a results sheet is often detraining in disguise.

The 35, 45 and 60 inflection points

That science maps onto the three places the RUN analysis flags as inflection points on the qualifying chart.

At age 35, the BAA gives a 5-minute easing. The Tanaka and Seals review suggests there is essentially no measurable performance penalty yet, so the standard is, if anything, slightly generous to a runner training continuously since their 20s. RUN’s data shows qualification rates of 14 to 18 percent for runners in their 40s and early 50s, well above the 10 to 12 percent rate for runners in their late 20s.

At age 45, the standard jumps another 10 minutes. By the Burtscher group’s estimate, a steady-training athlete loses about 5 percent of VO2max per decade, and a 10-minute concession over five years runs ahead of that arithmetic. Statistically, this is the BQ sweet spot. Under the old qualifying times the 45-49 group qualified at 17 to 18 percent; under the tighter 2026 standards, closer to 13 percent.

At age 60, both biology and the qualifying chart shift. Tanaka and Seals describe an accelerated VO2max decline starting in the late 50s, slightly steeper for women than men. The BAA has now widened the gap between the 55-59 and 60-64 age groups to 20 minutes, up from 15. RUN’s 2025 sample shows about 20 percent of runners aged 60 and over hit their qualifying times, a rate barely changed because the BAA left the 60-plus times alone.

What everyday qualifiers actually do

The RUN piece looked at seven non-elite runners who eventually qualified. The pattern was not a sudden breakthrough but multiple marathons over multiple years with steady annual improvement. Six of the seven took at least four marathons to BQ. One runner, E.B., shaved 39 minutes off her time over 11 years to reach a 3:30. Another, S.R., dropped from a 4:42 to a 3:38:57 over five attempts in her late 30s and early 40s.

That fits the Burtscher group’s training-volume finding. The runners who hit a BQ were the ones who could absorb structured volume year after year without injury, not the ones chasing one breakthrough.

Ben Mark, the runner who DNF’d in Philadelphia in 2019, eventually came back to running with a different goal. “You can get faster, you can balance running with kids, you can do all these things,” he told Nolan. He is running Boston this year for charity, after his mother’s cancer diagnosis, and has not yet qualified on time. “I still really want to qualify. I have plenty of time. I think I could even break three at some point in the next decade, and I’m just going to do it by doing the training.”

The science supports that timeline. Peak endurance performance does not collapse at 40, and the per-decade VO2max losses masters athletes post are mostly tied to how consistently they have trained, not to a calendar. The Boston ladder gives back enough time at 35, 45 and 60 to keep the goal mathematically open well into middle age for someone willing to do the work.

References

1. Tanaka H, Seals DR. Endurance exercise performance in Masters athletes: age-associated changes and underlying physiological mechanisms. Journal of Physiology 586(1):55-63. 2008. https://doi.org/10.1113/jphysiol.2007.141879
2. Burtscher J, Strasser B, Burtscher M, Millet GP. The impact of training on the loss of cardiorespiratory fitness in aging masters endurance athletes. International Journal of Environmental Research and Public Health 19(17):11050. 2022. https://doi.org/10.3390/ijerph191711050
3. Nolan A. Will you ever BQ? Here’s what the data says. RUN | Powered by Outside. 2025. https://run.outsideonline.com/road/road-racing/qualify-for-the-boston-marathon/