Fitness Benchmarks: Are You Actually Getting Fitter?

Written by:

Cliff Pittman

CTS Pro Ultrarunning Coach

Updated On

May 19, 2026

The value proposition for exercise is that if you put in the effort, you will be rewarded with improved fitness. But how do you know it’s working? One of the challenges with endurance training is that meaningful adaptations happen slowly and take a long time to show up in obvious ways. In my experience coaching beginners through elite runners, the athletes who stay on target and achieve long-term goals track their progress with a combination of reliable fitness benchmarks.

Finding Signs of Progress

There are many ways to evaluate progress over time, and the benchmarks that work best for you may depend on how structured your training is and what tools you have available to you. It’s important to recognize that gadgets, subscription apps, and laboratory are great if you have access to them, but you can accurately gauge your progress in low-tech ways.

Here are three tiers of fitness benchmarks for ultrarunners, organized by how structured your training is and what tools you have available.

Tier 1 Fitness Benchmarks: Accessible and Easiest to Track

These benchmarks require limited technology, just a heart rate monitor and a running app. They even work well for athletes who are not following a structured training plan or working with a coach.

Endurance Run Heart Rate Trend Over Time

As your cardiovascular fitness improves, stroke volume increases. Your heart gets stronger and pumps more blood per beat. Because of that, it doesn’t need to beat as frequently to deliver oxygen to working muscles. Over a period of three to six months, your average heart rate during steady endurance runs may gradually decrease. This is most evident for new runners or people getting back in shape after a long hiatus. For more experienced runners, this is a more difficult benchmark to use because changes in heart rate response at an aerobic pace will be more subtle.

It’s important to compare similar runs when using this benchmark. That means the same route, same effort level (pace and perceived exertion), and similar weather conditions (temp, wind).

Faster Strava Segments

Most runners have Strava or something similar that allows athletes to record repeated times over designated segments of local routes. Segments are great for informal performance testing because you’re always running the same terrain and distance with the same start and finish points. Running a segment faster under comparable conditions (wind, temperature, humidity) can be an indicator of improved fitness.

Two caveats on Strava segments:

1. The trend means more than the outlier. Pay more attention to the trend of segment times over a period of weeks or month. A super-fast segment time that’s a total outlier was probably just a great day or weather assisted. But gradually trending faster on a segment is a good indicator of real progress.
2. Don’t chase segment PRs on every run. You may run the same segment on a recovery day, an endurance run, and an interval day. These are different runs with different purposes, so don’t expect fast segments all the time. For benchmarking purposes, use segments intentionally, on days designed for harder efforts, and at points in your training cycle where fatigue levels are comparable.

Tier 2 Fitness Benchmarks: Best for Athletes On Structured Plans

If you follow a structured ultramarathon training plan with dedicated interval workouts, you can use more precise training data to evaluate your progress over time

Comparing Workouts Across Training Blocks

The concept is straightforward: Repeat the same workout at similar points in different training cycles and compare the output.

Here’s a practical example using a workout of 4 × 10-minutes at lactate threshold effort. In your current training block, you average Normalized Graded Pace (NGP, similar to Strava’s Grade Adjusted Pace) of 7:00/mile. After the current training block and a recovery week, you run the same workout in your next training block and average 6:50/mile. Same intensity, faster pace, better output, indicating that your threshold has likely improved.

For trail runners, NGP is the best metric to use for this comparison because it accounts for elevation and terrain, making it more reliable comparison than raw pace alone.

Caveats to comparing workouts across training blocks:

• Use the same workout structure (same interval type, same duration, same recovery between intervals) each time.
• Run in similar conditions (temp, wind, etc.)
• Do the workout with a similar level of fatigue. Don’t compare a workout done fresh to one completed deep in a training block when accumulated fatigue is high. That’s not a fitness comparison; it’s a fatigue comparison.

Tier 3 Fitness Benchmarks: Greatest Precision

If you have access to a lab, formal physiological testing provides precise benchmarks that paint the clearest picture of progression in endurance performance. Although you can test a lot of things in the lab, the most practical and useful test for an ultrarunner is a lactate threshold test, specifically testing and tracking the progress of your LT2 or “second lactate threshold”. LT2 is the intensity at which blood lactate levels start rising dramatically, often referred to simply as “lactate threshold” or “anaerobic threshold”.

Testing LT2 in a Lab

When we test trail runners in the lab, you start at an easy pace and we increase the pace in stages every few minutes. Your blood lactate level is measured from drop of blood at the end of each stage. Depending on the lab, you may also wear a mask that continuously analyzes the composition of exhaled air (which allows us to determine how much carbohydrate and fat you’re burning as you run). After the test, we can identify threshold breakpoints (LT1 and LT2) and use that information to create highly individualized training zones.

You know you’re getting faster or making progress in terms of raising your LT2 performance if you reach LT2 at a faster pace than before. Competitive athletes may perform two or even three lab tests each year, typically at comparable points in the season, to evaluate both seasonal and annual progress.

Field Testing for LT2

If you don’t have access to a lab, you can still test your threshold pace and heart rate with reasonably accuracy with a maximal 30-minute effort on a flat course. Your average heart rate over the final 20 minutes gives a reliable estimate of your threshold heart rate, and your average pace over the full effort approximates threshold pace. Repeating the field test again after one or more training blocks can indicate whether your threshold pace has improved. Typically, you want at least 8 weeks between field tests, and you want to be rested for the test. Beginners may see a greater progression in threshold heart rate values but more experienced runners will see little change in threshold heart rate as threshold pace continues to improve.

How to Combine Fitness Benchmarks

Meaningful and noticeable improvements in fitness take time to develop, so you shouldn’t look for signals of improvement after every workout. Progress will reveal itself as a pattern of outputs measured consistently over time.

Start with Tier 1: Over a period of weeks and months, look for a downward trend in average heart rate during endurance runs. Also watch for a faster trend in Strava segments during moderate and fast paced runs. Just remember that not chase Strava segments on easy days!

Add Tier 2: If you’re following a structured training plan, compare interval performance data from one training block against the same interval workout in subsequent training blocks. Depending on the purpose of the training block, this could mean comparing threshold intervals, VO2 max intervals, or another specific intensity and duration.

Invest in Tier 3: Field testing and lab testing are great ways to get precise data about your fitness. I recommend an annual lab test, either at the beginning of training for the year or at the point where training moves from generalized aerobic conditioning to more event-specific preparation. Some athletes use a combination of lab and field testing to create a more complete record of progress over time.

The Bottom Line

It’s difficult to recognize progress unless you look for it, and comparing your current and previous performances is a good way to tell whether your training is actually improving your fitness.

No matter which benchmarks you use, remember:

• Track consistently, keeping as many variables constant as you can.
• Give trends time to develop. You do not improve (or get worse) overnight.
• Only compare yourself to yourself. Training adaptation is 100% individual.