# Change in mitochondrial capacity in elite triathletes, cyclists, and wrestlers over a training period of 28 days

## TL;DR

This study shows that mitochondrial capacity in elite athletes improves significantly over 28 days of training, as measured by changes in deoxygenated hemoglobin.

## Contribution

The study demonstrates the effectiveness of NIRS-derived τ rates for monitoring mitochondrial adaptations in elite athletes over short training periods.

## Key findings

- Significant improvements in mitochondrial capacity were observed during the second and third occlusion periods after 28 days of training.
- There was a stronger negative correlation between τ rates and VO2max after training compared to before.
- 14 out of 16 athletes showed measurable improvements in mitochondrial capacity.

## Abstract

This study investigated the change in mitochondrial capacity and VO2max in elite triathlon, cycling, and Greco-Roman wrestling athletes over a 28-day training period.

Sixteen elite athletes (23 ± 2.5 years; 176 ± 6 cm; 76 ± 8 kg; 65 ± 6.9 ml/min/kg) participated. Mitochondrial capacity was assessed before (pre) and after (post) a 28-day training period by measuring the increase in deoxygenated hemoglobin (HHb) in the m. vastus lateralis during three consecutive one-minute rapid cuff occlusion periods using near-infrared spectroscopy. VO2max was measured via a treadmill ramp test at the same time points.

The analyses revealed significant differences between pre- and post-measurements, with significant improvements in the second (Δτ2 = − 3.4 ± 2.7 s, p = 0.001) and third (Δτ3 = − 5.0 ± 5.1 s, p = 0.006) occlusion period. Correlation analyses demonstrated a moderate negative relationship between the first occlusion tau (τ) rate and VO2max at pre-test (r = − 0.58, p = 0.02) and an even stronger negative correlation at post-test (r = − 0.62, p = 0.01). Within-subject analysis identified 14 athletes as responders.

The changes in τ rates indicate significant improvements in mitochondrial capacity over a period of 28 days in elite athletes, underscoring the utility of NIRS-derived τ rates for monitoring changes in elite athletes.