Institute of Sport Science and Innovations, Lithuanian Sports University, Kaunas, Lithuania.
Department of Sports Medicine, Prevention and Rehabilitation, Johannes Gutenberg University Mainz, Mainz, Germany.
Eur J Appl Physiol. 2024 Apr;124(4):1297-1309. doi: 10.1007/s00421-023-05366-2. Epub 2023 Nov 28.
This study aimed to investigate the impact of sprint interval training (SIT) on both the acute and 3-week modulations of cell-free DNA (cfDNA), as well as its association with neuromuscular fatigue and physical performance in healthy young and old men.
Ten young (20-25 year old) and nine elderly (63-72 year old) healthy men performed nine SIT sessions consisting of 4-to-6-all-out cycling repetitions of 30 s interspaced with 4-min rest intervals. We compared the maximal voluntary contractions torque, central activation ratio, low-frequency fatigue (LFF), and cfDNA concentrations between the groups before, immediately after, 1 h after, and 24 h after the first and ninth SIT sessions.
The plasma cfDNA levels were increased post-exercise (from 1.4 ± 0.258 to 1.91 ± 0.278 ng/ml (P < 0.01) on a log10 scale), without significant differences between the groups. However, older individuals showed a slight decrease in the baseline cfDNA values, from 1.39 ± 0.176 to 1.29 ± 0.085 ng/ml on a log10 scale, after 3 weeks (P = 0.043). Importantly, the elevation of the post-exercise cfDNA values was correlated with an increase in LFF in both groups. Three weeks of SIT induced an improvement in the recovery of LFF (main session effect, P = 0.0029); however, only the young group showed an increase in aerobic capacity (VO) (from 40.8 ± 6.74 to 43.0 ± 5.80 ml/kg/min, P = 0.0039).
Three weeks of SIT diminished the baseline cfDNA values in the old group, together with an improvement in the recovery of LFF. However, VO was increased only in the young group.
本研究旨在探究冲刺间歇训练（SIT）对游离 DNA（cfDNA）的急性和 3 周调节的影响，以及其与健康年轻和老年男性的神经肌肉疲劳和身体表现的关系。
10 名年轻（20-25 岁）和 9 名老年（63-72 岁）健康男性进行了 9 次 SIT 训练，包括 4-6 次全力自行车重复，每次 30 秒，间隔 4 分钟休息时间。我们比较了两组在第一次和第九次 SIT 训练前后、训练后 1 小时和 24 小时的最大自主收缩扭矩、中枢激活比、低频疲劳（LFF）和 cfDNA 浓度。
运动后血浆 cfDNA 水平升高（从对数 10 标度的 1.4±0.258 增加到 1.91±0.278 ng/ml（P<0.01）），但两组之间没有差异。然而，老年组在 3 周后，cfDNA 值的基线略有下降，从对数 10 标度的 1.39±0.176 减少到 1.29±0.085 ng/ml（P=0.043）。重要的是，运动后 cfDNA 值的升高与两组的 LFF 增加有关。3 周的 SIT 诱导了 LFF 恢复的改善（主训练效果，P=0.0029）；然而，只有年轻组的有氧能力（VO）增加（从 40.8±6.74 增加到 43.0±5.80 ml/kg/min，P=0.0039）。
3 周的 SIT 降低了老年组的基线 cfDNA 值，同时改善了 LFF 的恢复。然而，VO 仅在年轻组中增加。
