Core Strength • 6 Min Read • Updated July 2026
Most healthy adults can hold a proper forearm plank for 60 to 90 seconds. Under 30 seconds suggests core endurance worth working on; two minutes is solidly above average; and three minutes or more puts you in the range where the U.S. military hands out maximum points. Beyond about four minutes, you're testing stubbornness more than fitness — even elite standards top out before then.
| Rating | Hold Time |
|---|---|
| Needs work | Under 30 seconds |
| Below average | 30 – 60 seconds |
| Average | 60 – 90 seconds |
| Good | 90 seconds – 2 minutes |
| Very good | 2 – 3 minutes |
| Excellent (military max territory) | 3 – 4 minutes |
All three major U.S. service fitness tests now use the forearm plank, and their published standards are the best objective benchmarks available.
| Test | Maximum Points | Minimum | Notes |
|---|---|---|---|
| Marine Corps PFT | 3:45 | 1:10 | Same scale for all ages and sexes |
| Navy PRT | 3:20 – 3:24 (men 17-24) | ~1:10 | Varies by age and sex |
| Air Force PFRA | 3:40 (men under 25) | ~1:35 | Core option, varies by age/sex |
Check your exact score against the official tables with our USMC PFT Calculator, Navy PRT Calculator, and Air Force PT Test Calculator — all three use the current published standards, not approximations.
Repetitive spinal flexion under load — the sit-up and crunch pattern — was linked to a high rate of lower-back complaints across the services, while isometric trunk endurance (what the plank measures) correlates better with injury resistance and load-carriage performance. The Marine Corps made the plank mandatory in 2023; the Navy moved in 2020; and the Air Force added it as a core option in its current assessment.
Plank endurance responds fast to frequency. Three to four sessions a week of accumulating time — say, 3 sets at 70-80% of your max hold with a minute's rest — typically adds 30-60 seconds within a month. Two form cues do most of the work: squeeze your glutes to keep hips from sagging (the most common failure point), and breathe steadily instead of holding your breath. Past three minutes, add difficulty rather than time: weighted planks, feet-elevated planks, or body saws build strength the clock can't measure.
Planks are one piece of the picture — for overall fitness benchmarks, see your strength level with the One Rep Max Calculator and your grip against population norms with our Grip Strength Chart.
Yes — two minutes with strict form puts you above the general population average and around the "Good" band of every military scoring table. Renowned spine researcher Stuart McGill has argued two minutes is a reasonable benchmark of healthy core endurance for most adults.
Not directly. Visible abs are overwhelmingly a body-fat question, and very long planks train endurance rather than muscle size. If aesthetics are the goal, train the core with progressive resistance and manage body fat — estimate yours with our Body Fat Calculator.
Isometric endurance is unusually sensitive to sleep, heat, and motivation — swings of 20-30% between days are normal. Test under consistent conditions (same time of day, rested) when you want a real progress check.
Often they're actually recommended, because the plank trains the trunk without spinal flexion. But back pain has many causes — anyone with an existing condition should clear exercise selection with a physio or physician rather than a blog post.