AIM: To determine cerebral blood-flow velocity (CBFV) and parameters of dynamic cerebral autoregulation (CA) during and after exhausting resistance exercise. METHODS: Strength endurance (23 repetitions) and maximal strength training (8 repetitions) in 16 female and 16 male athletes on a leg curler (m. quadriceps training; approx. 2 s contraction) in the upright position. Registration of ECG, blood pressure by Finapres, CBFV by transcranial Doppler (TCD), and breathing by a Zak breathing-belt. Additional repetitive ergospirometry (O2-uptake, CO2-elimination, ventilation) and blood gas analyses were performed in a subgroup of seven athletes. From BP and CBFV cerebrovascular resistance (CVR), pulsatility index (PI) as well as LF-power, gain and phase-angle (frequency analysis) were derived. RESULTS: All athletes showed significant (p<0.01) 15 % to 30 % increases in CBFV during both training sets without signs of flow depression due to Valsalva maneuvers. In the early recovery, when blood pressure rapidly decreased, CBFV amplitude significantly (p<0.01) increased for 60-80 seconds with mean flow (Vm) at the exercise level, while CVR and PI showed conflicting results, similar to a presyncopal reaction. Ergospirometry and blood gas analyses revealed no evidence of major changes in pCO2, but phase angle was reduced (p<0.001) after exercise, together with an LF power increase (p<0.001). CONCLUSION: An unexpected increase in CBFV amplitude and in Vm occurs directly after dynamic resistance exercise without increased pCO2, which is comparable to a maximum leg press with hypercapnia. CVR and PI results as well as data from frequency analysis show similarities to presyncopal reactions, on the one hand, and point towards a temporarily disturbed cerebral autoregulation, on the other.
AIM: To determine cerebral blood-flow velocity (CBFV) and parameters of dynamic cerebral autoregulation (CA) during and after exhausting resistance exercise. METHODS: Strength endurance (23 repetitions) and maximal strength training (8 repetitions) in 16 female and 16 male athletes on a leg curler (m. quadriceps training; approx. 2 s contraction) in the upright position. Registration of ECG, blood pressure by Finapres, CBFV by transcranial Doppler (TCD), and breathing by a Zak breathing-belt. Additional repetitive ergospirometry (O2-uptake, CO2-elimination, ventilation) and blood gas analyses were performed in a subgroup of seven athletes. From BP and CBFV cerebrovascular resistance (CVR), pulsatility index (PI) as well as LF-power, gain and phase-angle (frequency analysis) were derived. RESULTS: All athletes showed significant (p<0.01) 15 % to 30 % increases in CBFV during both training sets without signs of flow depression due to Valsalva maneuvers. In the early recovery, when blood pressure rapidly decreased, CBFV amplitude significantly (p<0.01) increased for 60-80 seconds with mean flow (Vm) at the exercise level, while CVR and PI showed conflicting results, similar to a presyncopal reaction. Ergospirometry and blood gas analyses revealed no evidence of major changes in pCO2, but phase angle was reduced (p<0.001) after exercise, together with an LF power increase (p<0.001). CONCLUSION: An unexpected increase in CBFV amplitude and in Vm occurs directly after dynamic resistance exercise without increased pCO2, which is comparable to a maximum leg press with hypercapnia. CVR and PI results as well as data from frequency analysis show similarities to presyncopal reactions, on the one hand, and point towards a temporarily disturbed cerebral autoregulation, on the other.
Authors: Jessica J Steventon; Alex B Hansen; Joseph R Whittaker; Kevin W Wildfong; Daniela Nowak-Flück; Michael M Tymko; Kevin Murphy; Phil N Ainslie Journal: Front Physiol Date: 2018-11-21 Impact factor: 4.566
Authors: Marc Kermorgant; Nathalie Nasr; Marc-Antoine Custaud; Nastassia Navasiolava; Philippe Arbeille; Patrick Guinet; Marc Labrunée; Florent Besnier; Dina N Arvanitis; Marek Czosnyka; Jean-Michel Senard; Anne Pavy-Le Traon Journal: Front Physiol Date: 2019-08-27 Impact factor: 4.566