Every week, I review the latest sports nutrition and exercise research to understand what the findings mean for athletes. This week, a study of national-level rowers found that 2,000 m performance improved over eight weeks, while several physiological and blood markers showed no statistically significant changes.
The study
Researchers looked back at routine monitoring data from 16 national-level male rowers across eight weeks of training.
They compared performance on a 2,000 m rowing ergometer test with several measures commonly used to monitor training:
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Heart rate at a fixed power output
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Blood lactate responses
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Power output at a blood lactate concentration of 4 mmol/L
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Blood markers, including hemoglobin, hematocrit, urea nitrogen, and creatine kinase
They also examined whether changes in these measures were associated with changes in each rower's 2,000 m performance.
This was a retrospective study with no control group. It tracked what happened during an existing training period, rather than testing one training program against another.
The results
Average 2,000 m time improved from 370.39 to 368.34 seconds: approximately two seconds faster, or about 0.6%.
That improvement was statistically significant.
However, heart rate at a fixed power, blood lactate, and power at 4 mmol/L lactate did not change significantly. The blood markers also showed no significant overall changes.
Changes in these monitoring measures weren't reliably associated with which rowers improved their 2,000 m times the most.
This doesn't mean the rowers' physiology stayed exactly the same. With only 16 athletes, the estimates were uncertain, and a result that isn't statistically significant doesn't establish that nothing changed.
What the study shows is that the measured markers didn't clearly reflect the improvement seen in the performance test.
Why it matters
Endurance athletes often use heart rate, lactate, and other monitoring data to judge whether training is working.
Those numbers can provide useful context, but they may not capture every small improvement in performance, particularly over a short period in already well-trained athletes.
Here, the rowers completed the same distance faster without clear changes in several commonly tracked measures.
For athletes, that supports keeping repeatable performance tests in the picture when assessing progress. A monitoring number and a performance result answer related, but different, questions.
My thoughts
I find this result humbling. We can collect a lot of information about an athlete and still struggle to explain a relatively straightforward outcome: they got faster.
The study can't tell us what caused the improvement. There was no control group, and the researchers were looking back at existing data.
But it does reinforce something practical for me: keep testing the thing you're trying to improve.
That might be a rowing time trial, a familiar running route, or a benchmark workout. Make the conditions as consistent as you reasonably can, then consider the result alongside how you're recovering and how training feels.
I wouldn't discard heart-rate or lactate data because of this study. I also wouldn't conclude that training has failed simply because one of those numbers hasn't moved.