PMID- 38393260
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20240227
IS  - 2075-4663 (Electronic)
IS  - 2075-4663 (Linking)
VI  - 12
IP  - 2
DP  - 2024 Jan 28
TI  - Agreement between Ventilatory Thresholds and Bilaterally Measured Vastus 
      Lateralis Muscle Oxygen Saturation Breakpoints in Trained Cyclists: Effects of 
      Age and Performance.
LID - 10.3390/sports12020040 [doi]
LID - 40
AB  - This study focused on comparing metabolic thresholds derived from local muscle 
      oxygen saturation (SmO(2)) signals, obtained using near-infrared spectroscopy 
      (NIRS), with global pulmonary ventilation rates measured at the mouth. It was 
      conducted among various Age Groups within a well-trained cyclist population. 
      Additionally, the study examined how cycling performance characteristics impact 
      the discrepancies between ventilatory thresholds (VTs) and SmO(2) breakpoints 
      (BPs). METHODS: Junior (n = 18) and Senior (n = 15) cyclists underwent 
      incremental cycling tests to assess their aerobic performance and to determine 
      aerobic (AeT) and anaerobic (AnT) threshold characteristics through pulmonary gas 
      exchange and changes in linearity of the vastus lateralis (VL) muscle SmO(2) 
      signals. We compared the relative power (Pkg) at ventilatory thresholds (VTs) and 
      breakpoints (BPs) for the nondominant (ND), dominant (DO), and bilaterally 
      averaged (Avr) SmO(2) during the agreement analysis. Additionally, a 30 s sprint 
      test was performed to estimate anaerobic performance capabilities and to assess 
      the cyclists' phenotype, defined as the ratio of P@VT2 to the highest 5 s sprint 
      power. RESULTS: The P(kg)@BP for Avr SmO(2) had higher agreement with VT values 
      than ND and DO. Avr SmO(2) P(kg)@BP1 was lower (p < 0.05) than P(kg)@VT1 (mean 
      bias: 0.12 +/- 0.29 W/kg; Limits of Agreement (LOA): -0.45 to 0.68 W/kg; R(2) = 
      0.72) and mainly among Seniors (0.21 +/- 0.22 W/kg; LOA: -0.22 to 0.63 W/kg); there 
      was no difference (p > 0.05) between Avr P(kg)@BP2 and P(kg)@VT2 (0.03 +/- 0.22 
      W/kg; LOA: -0.40 to 0.45 W/kg; R(2) = 0.86). The bias between two methods 
      correlated significantly with the phenotype (r = -0.385 and r = -0.515 for AeT 
      and AnT, respectively). CONCLUSIONS: Two breakpoints can be defined in the 
      NIRS-captured SmO(2) signal of VL, but the agreement between the two methods at 
      the individual level was too low for interchangeable usage of those methods in 
      the practical training process. Older cyclists generally exhibited earlier 
      thresholds in muscle oxygenation signals compared to systemic responses, unlike 
      younger cyclists who showed greater variability and no significant differences in 
      this regard in bias values between the two threshold evaluation methods with no 
      significant difference between methods. More sprinter-type cyclists tended to 
      have systemic VT thresholds earlier than local NIRS-derived thresholds than 
      athletes with relatively higher aerobic abilities.
FAU - Reinpold, Karmen
AU  - Reinpold K
AUID- ORCID: 0000-0002-9987-6787
AD  - School of Natural Sciences and Health, University of Tallinn, 10120 Tallinn, 
      Estonia.
FAU - Rannama, Indrek
AU  - Rannama I
AUID- ORCID: 0000-0001-7698-6003
AD  - School of Natural Sciences and Health, University of Tallinn, 10120 Tallinn, 
      Estonia.
FAU - Port, Kristjan
AU  - Port K
AD  - School of Natural Sciences and Health, University of Tallinn, 10120 Tallinn, 
      Estonia.
LA  - eng
PT  - Journal Article
DEP - 20240128
PL  - Switzerland
TA  - Sports (Basel)
JT  - Sports (Basel, Switzerland)
JID - 101722684
PMC - PMC10892087
OTO - NOTNLM
OT  - NIRS
OT  - SmO2 breakpoints
OT  - gas exchange
OT  - high-level cycling
OT  - performance
OT  - phenotype
OT  - ventilatory thresholds
COIS- The authors declare no conflicts of interest.
EDAT- 2024/02/23 12:43
MHDA- 2024/02/23 12:44
PMCR- 2024/01/28
CRDT- 2024/02/23 10:34
PHST- 2024/01/04 00:00 [received]
PHST- 2024/01/21 00:00 [revised]
PHST- 2024/01/25 00:00 [accepted]
PHST- 2024/02/23 12:44 [medline]
PHST- 2024/02/23 12:43 [pubmed]
PHST- 2024/02/23 10:34 [entrez]
PHST- 2024/01/28 00:00 [pmc-release]
AID - sports12020040 [pii]
AID - sports-12-00040 [pii]
AID - 10.3390/sports12020040 [doi]
PST - epublish
SO  - Sports (Basel). 2024 Jan 28;12(2):40. doi: 10.3390/sports12020040.