Juškevičiūtė E, Neuberger E, Eimantas N, Venckunas T, Kamandulis S, Simon P, Brazaitis M. Three-week sprint interval training (SIT) reduces cell-free DNA and low-frequency fatigue but does not induce VO2max improvement in older men.
Eur J Appl Physiol 2024;
124:1297-1309. [PMID:
38015284 DOI:
10.1007/s00421-023-05366-2]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 10/29/2023] [Indexed: 11/29/2023]
Abstract
PURPOSE
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.
METHODS
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.
RESULTS
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 (VO2max) (from 40.8 ± 6.74 to 43.0 ± 5.80 ml/kg/min, P = 0.0039).
CONCLUSION
Three weeks of SIT diminished the baseline cfDNA values in the old group, together with an improvement in the recovery of LFF. However, VO2max was increased only in the young group.
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