Journal Articles

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Start date: 2024Subject: search.filters.subject.resistance exercise

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    No difference in mean middle cerebral artery blood velocity responses between lower- and upper-body unilateral resistance exercise in untrained individuals
    (John Wiley and Sons Ltd on behalf of The Physiological Society, 2025-10-06) Korad S; Mündel T; Perry BG
    Dynamic resistance exercise (RE) produces sinusoidal fluctuations in blood pressure that are mirrored by middle cerebral artery blood velocity (MCAv). However, whether lower- or upper-body RE elicits a differential cerebrovascular response has not yet been examined. We investigated the cerebrovascular response to lower-body RE versus upper-body RE in 15 healthy untrained individuals (12 females and 3 males; mean ± SD; age 25 ± 6 years, height 179 ± 10 cm, weight 71 ± 15 kg and body mass index 24 ± 6 kg/m2). Participants completed four sets of 10 paced repetitions (15 repetitions/min) of unilateral leg-extension exercise and unilateral bicep-curl exercise at 60% of predicted one-repetition maximum (leg extension 30 ± 9 kg and bicep curl 7 ± 3 kg). Beat-to-beat blood pressure, bilateral MCAv and partial pressure of end-tidal carbon dioxide were measured throughout. Within-exercise mean arterial blood pressure (MAP) and mean MCAv were averaged across the set. Additionally, zenith, nadir and zenith-to-nadir difference in MAP and mean MCAv for each repetition were averaged across each set. Baseline measures preceding each set were not different for all dependent variables, with no significant interaction differences observed (all p > 0.161). The mean MCAv within exercise decreased across sets (set effect p < 0.001), but MAP did not (p = 0.071). No interaction effects were observed for any dependent variables (all p > 0.06), However, there was a zenith-to-nadir difference in mean MCAv (p = 0.008), although post hoc tests revealed no significant difference between exercises (all p > 0.078). There were no differences in the cerebrovascular and cardiovascular responses to lower- and upper-body RE, with similar sinusoidal fluctuations in MAP and MCAvmean present during both exercises.
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    Larger reductions in blood pressure during post-exercise standing, but not middle cerebral artery blood velocity, in resistance-trained versus untrained individuals.
    (John Wiley and Sons Ltd on behalf of The Physiological Society, 2024-12-25) Korad S; Mündel T; Perry BG; Ogoh S
    Dynamic resistance exercise (RE) produces sinusoidal fluctuations in blood pressure, with hypotension and cerebral hypoperfusion commonly observed immediately following RE. Whether the cerebral vasculature adapts to these regular blood pressure challenges is unclear. This study examined the cerebrovascular response to post-dynamic RE orthostasis. RE-trained (n = 15, female = 4) and healthy untrained individuals (n = 15, female = 12) completed five stands: one after seated rest, with each of the subsequent four stands occurring immediately following a set of 10 repetitions of unilateral leg extension exercise at 60% of their one repetition maximum. Beat-to-beat blood pressure, mean middle cerebral artery blood velocity (MCAvmean) and end-tidal carbon dioxide were measured throughout. During standing the mean arterial blood pressure (MAP) and MCAvmean nadirs were identified. There was no difference between groups for age (mean ± SD, 26 ± 7 RE-trained vs. 25 ± 6 years untrained, P = 0.683) or weight (78 ± 15 vs. 71 ± 15 kg, P = 0.683). At MAP nadir during the post-exercise stand, a greater reduction in MAP was observed in the RE-trained group (e.g., set 4, -45 ± 11 vs. -36 ± 6 mmHg, training effect P = 0.026). However, post-exercise stand MCAvmean at MCAvmean nadir was not different (e.g., set 4, -20 ± 7 vs. -17 ± 6 cm/s, interaction effect P = 0.478). Rate of regulation was higher in the RE-trained group (set 1, 0.301 ± 0.170 vs. 0.167 ± 0.009, training effect P = 0.023). Despite RE-trained individuals demonstrating greater absolute reductions in MAP during orthostasis following RE, there were no differences in MCAvmean, suggesting that habitual RE may mitigate post-exercise cerebral hypoperfusion.
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    Neurovascular coupling during dynamic upper body resistance exercise in healthy individuals.
    (John Wiley and Sons on behalf of The Physiological Society, 2024-09-25) Korad S; Mündel T; Perry BG; Ogoh S
    During unilateral static and rhythmic handgrip exercise, middle cerebral artery blood velocity (MCAv) increases in the contralateral side to the exercising limb. However, whether this neurovascular coupling-mediated increase in contralateral MCAv is apparent against a background of fluctuating perfusion pressure produced by dynamic resistance exercise (RE) is unclear. We examined the cerebral haemodynamic response to unilateral dynamic RE in 30 healthy individuals (female = 16, mean ± SD: age, 26 ± 6 years; height, 175 ± 10 cm; weight, 74 ± 15 kg; body mass index, 24 ± 5 kg m-2). Participants completed four sets of 10 paced repetitions (15 repetitions min-1) of unilateral bicep curl exercise at 60% of the predicted one-repetition maximum (7 ± 3 kg). Beat-to-beat blood pressure, bilateral MCAv and end-tidal carbon dioxide were measured throughout. One-way ANOVA was used to analyse cardiovascular variables and two-way ANOVA to analyse dependent cerebrovascular variables (side × sets, 2 × 5). A linear mixed model analysis was also performed to investigate the effects of end-tidal carbon dioxide and mean arterial blood pressure on MCAv. In comparison to baseline, within-exercise mean arterial blood pressure increased (P < 0.001) across the sets, whereas bilateral MCAv decreased (P < 0.001). However, no significant interaction effect was observed for any dependent variables (all P > 0.787). The linear mixed model revealed that end-tidal carbon dioxide had the greatest effect on MCAv (estimate = 1.019, t = 8.490, P < 0.001). No differences were seen in contralateral and ipsilateral MCAv during dynamic RE, suggesting that neurovascular coupling contributions during dynamic RE might be masked by other regulators, such as blood pressure.
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    The effects of habitual resistance exercise training on cerebrovascular responses to lower body dynamic resistance exercise: A cross-sectional study.
    (John Wiley and Sons Ltd on behalf of The Physiological Society., 2024-06-18) Korad S; Mündel T; Perry BG; Bailey D
    Dynamic resistance exercise (RE) produces sinusoidal fluctuations in blood pressure with simultaneous fluctuations in middle cerebral artery blood velocity (MCAv). Some evidence indicates that RE may alter cerebrovascular function. This study aimed to examine the effects of habitual RE training on the within-RE cerebrovascular responses. RE-trained (n = 15, Female = 4) and healthy untrained individuals (n = 15, Female = 12) completed four sets of 10 paced repetitions (15 repetitions per minute) of unilateral leg extension exercise at 60% of predicted 1 repetition maximum. Beat-to-beat blood pressure, MCAv and end-tidal carbon dioxide were measured throughout. Zenith, nadir and zenith-to-nadir difference in mean arterial blood pressure (MAP) and mean MCAv (MCAvmean) for each repetition were averaged across each set. Two-way ANOVA was used to analyse dependent variables (training × sets), Bonferroni corrected t-tests were used for post hoc pairwise comparisons. Group age (26 ± 7 trained vs. 25 ± 6 years untrained, P = 0.683) and weight (78 ± 15 vs. 71 ± 15 kg, P = 0.683) were not different. During exercise average MAP was greater for the RE-trained group in sets 2, 3 and 4 (e.g., set 4: 101 ± 11 vs. 92 ± 7 mmHg for RE trained and untrained, respectively, post hoc tests all P = < 0.012). Zenith MAP and zenith-to-nadir MAP difference demonstrated a training effect (P < 0.039). Average MCAvmean and MCAvmean zenith-to-nadir difference was not different between groups (interaction effect P = 0.166 and P = 0.459, respectively). Despite RE-trained individuals demonstrating greater fluctuations in MAP during RE compared to untrained, there were no differences in MCAvmean. Regular RE may lead to vascular adaptations that stabilise MCAv during RE.