Why can I only maintain my speed briefly when running in the anaerobic zone?
April 30, 2012 | 20,00 EUR | answered by Dr. med. Kathrin Hamann
I have been running for 6 years, the last 4 of them with a club: 2x speed training per week, running a 10k in a 4:20 pace, and a 5k in a 4:05 pace. For the past 1 1/2 years, I have been experiencing long phases where I can still do speed training with breaks as usual (e.g. 8x1km in 4:20), but during steady-paced long runs, I drop by 25-30 seconds per km after just a few minutes (e.g. during a 30-minute run at a 4:40-4:45 pace, after about 2km there is a drop in performance). This drop in performance only occurs during these long phases when I run without breaks. This suggests that when I try to run in the anaerobic zone and the body would need to rely on other substances (such as glycogen) when oxygen is not sufficient, the issue arises, which was not a problem until 1 1/2 years ago. A blood test showed everything was normal except for a slightly elevated TSH basal level (4.5), and iron levels were good. My heart is healthy, with a consistent maximum (184) and resting (39) heart rate for the past 3 years. The heart rate during exercise has decreased by about 10 beats, indicating improved fitness. However, my recovery has slowed me down even more. What is missing in the body in terms of substances, and how can it rely on them again? (Attached is the latest performance test)
Good evening,
this decrease in performance does not necessarily have to have a medical value or an organic cause.
During the anaerobic phase, the body relies on reserves, the combustion is then not optimal, as oxygen is lacking and energy is missing due to the not quite optimal combustion. Just like in a car engine that does not get enough air to effectively burn the fuel in the cylinder.
However, you are describing a decrease in performance that was not present a year ago, right?
This can have several causes: First, the training condition must be considered. Nutrition and fluid balance also play a crucial role. How is the liver and kidney functioning? How well does the lung work? What about the blood vessels themselves?
Aging processes based on the normal values in the check-ups have not progressed enough to be noticeable yet. However, the sum of many small changes can affect their performance decline.
High loads/speeds in the anaerobic range are also a burden on the heart and circulatory system. For this reason, they should not call up these performances so strongly and rather move in the optimal aerobic range.
Please do not worry, in most cases this development is age-related and normal without any medical significance.
All the best
Kind regards,
Dr. K. Hamann
