ECSS Paris 2023: CP-PN14
INTRODUCTION: Many previous studies indicate that acute or regular exercises reduce Pulse Wave Velocity (PWV) as an index of arterial stiffness. The increased arterial stiffness is an independent risk factor for future cardiovascular diseases, so preventing an increase in arterial stiffness by exercise is of paramount importance. One-legged physical exercises (aerobic, resistance, and stretching) acutely reduce arterial stiffness in the exercise limb, but not in the none-exercise limb. Blood flow in brachial artery as inactive limbs generally increases in moderate-(MOD) and severe-(SEV) intensity cycling exercises for lower limbs, but not in low-intensity cycling exercise (LOW). These data thus suggest that arterial stiffness responses to exercise are mainly affected by the difference in arterial segment and blood flow associated with exercise intensity. However, the influences of different intensity cycling exercises on segmental arterial stiffness are now well unknown. Therefore, this study aimed to examine the effects of acute different intensity cycling exercises on segmental arterial stiffness. METHODS: Nineteen young males and females (21 ± 2 years) participated in four separate trials of 40 min in random order and on different days: (1) resting and sitting on a comfortable chair, as a control (CON); (2) LOW; (3) MOD; and (4) SEV. Each exercise intensity was determined by heart rate levels; 100, 125, and 150 beats/min, respectively. Before (Pre) and immediately (Post 1) and 30 min (Post 2) after the exercises, heart-brachial PWV (hbPWV), which reflects arterial stiffness of the upper limbs from the aorta to the brachium; brachial-ankle PWV (baPWV), which reflects arterial stiffness of central (large arteries in the cardiothoracic region) and leg from the femoral to the ankle; and heart-ankle PWV (haPWV), which reflects systemic arterial stiffness, were measured as an index of segmental arterial stiffness. RESULTS: No significant differences in baseline parameters were observed among trials. After the exercise, the reductions in hbPWV were significantly higher in both MOD (6.1 ± 4.5%) and SEV (14.4 ± 11.6%) trials than in CON (-1.4 ± 6.0%) trials, but not in LOW (2.3 ± 6.0%) trials. On the other hand, interestingly, a significantly higher reduction in baPWV in both MOD (4.1 ± 5.2%) and SEV (4.2 ± 4.6%) trials and a tendency towards higher reduction in LOW (2.6 ± 4.0%) trials as compared to CON (-6.4 ± 18.9%) trials. Finally, the reductions in haPWV were significantly higher in all LOW (2.6 ± 3.6%), MOD (5.3 ± 3.9%), and SEV (9.1 ± 5.5%) trials than in CON (-3.7 ± 9.8%) trials, but not in trials. CONCLUSION: Our data indicate that cycling exercise of higher intensity induce reductions in relatively systemic arterial stiffness (i.e., blood flow increases in both active and inactive limbs), but lower intensity induce reductions only in the relatively limited and local arterial stiffness (i.e., blood flow increases only in active limbs).
Read CV Masato NishiwakiECSS Paris 2023: CP-PN14
INTRODUCTION: Athletes commonly wear compression garments during and after exercise, in the belief that compression garments improve blood flow. However, relatively little is known about how compression garments influence central haemodynamics. This ongoing study investigates differences in resting stroke volume while wearing custom-fit compression garments (which are designed to apply more consistent pressure and gradient) compared with commercial off-the-shelf compression garments. METHODS: Using thoracic electrical bioimpedance, stroke volume in two body orientations—standing and supine—while wearing custom-fit tights, custom-fit calf sleeves, off-the-shelf tights, off-the-shelf calf sleeves, and no compression garment was measured. Testing has been completed on eight physically active participants (5F, 3M), with an average height, weight, and age of 166.5cm, 71.6kg, 33.6 years of age for females and 171.8cm, 92.8kg, and 30.3 years of age for males respectively. 13 more participants will be tested. To explore the physiological mechanisms underlying these observations, a secondary analysis of differences in pressure exerted by custom-fit and off-the-shelf compression garments is also being conducted. A pressure sensor is placed under the compression garments at the medial and posterior aspect of the greatest circumference of the lower leg and on the midpoint between the inguinal crease and the superior-posterior border of the patella. RESULTS: The preliminary findings indicate a notable increase in stroke volume while wearing custom-fit tights in the standing orientation compared with the other conditions. This improvement suggests enhanced cardiac efficiency via the Frank-Starling mechanism, whereby the heart achieves greater output per beat due to an increased venous return. Data also reveals that off-the-shelf calf sleeves exert the highest pressure but yield minimal stroke volume improvements. By contrast, despite covering less than half the surface area of off-the-shelf tights, custom-fit calf sleeves demonstrate a comparable stroke volume increase in the standing position. CONCLUSION: This work will provide important new insights into how compression garments influence central haemodynamics, and the variability between custom-fit and off-the-shelf compression garments. These data will improve understanding of how compression garments work physiologically and will inform decision-making about the most effective type of compression garment for athletes.
Read CV Samuel LewisECSS Paris 2023: CP-PN14
INTRODUCTION: Hypertension is a major global health concern and a leading risk factor for cardiovascular diseases and premature mortality. While regular physical activity is an effective strategy for managing blood pressure (BP), individual responses to exercise vary, highlighting the need for reliable predictors of long-term BP adaptation. The magnitude of postexercise hypotension (PEH), the acute BP reduction following a workout, has emerged as a potential indicator of chronic BP improvements [1,2,3]. However, most studies have focused on acute BP changes in response to exhaustive exercise, and little is known about the relationship between acute BP responses to guideline-conforming training intensities and long-term benefits [2,3]. Therefore, this study aimed to investigate whether PEH following continuous submaximal exercise and maximal exercise are correlated, and whether they are associated with long-term BP reductions. METHODS: Thirty-three untrained, healthy adults (18–45 years) participated in an 8-week aerobic training program, completing three 30-minute sessions per week at a vigorous intensity set midway between two lactate thresholds. BP was measured at rest and 10 minutes after a graded exercise test during baseline testing (MAX), following a training bout at the start of the intervention period (SUBMAX), and at rest after the 8-week training period. Changes in BP were analyzed using paired t-tests. The relationships between PEH following SUBMAX and MAX, as well as between acute and long-term BP changes, were assessed using Pearson correlation. To minimize the impact of math coupling on the strength of associations between PEH and long-term BP changes, the average of the two respective resting BP measurements was used. RESULTS: A significant acute decrease in BP was observed following SUBMAX (systolic: -4.6 [95% CI: -6.9, -2.3] mmHg, p < .001; diastolic: -3.1 [-5.4, -0.8] mmHg, p = .011) and in systolic BP following MAX (-3.0 [-5.3, -0.7] mmHg, p = .013). A significant reduction in resting diastolic BP was observed after the 8-week training intervention (-2.3 [-4.9, -0.6] mmHg, p = .015). PEH after SUBMAX and MAX was significantly correlated (systolic: r = 0.68 [0.44, 0.83], p < .001; diastolic: r = 0.54 [0.24, 0.75], p = .001). Correlations between PEH and long-term systolic BP reduction were statistically significant for both SUBMAX (systolic: r = 0.58 [0.30, 0.77], p < .001; diastolic: r = 0.56 [0.27, 0.76], p < .001) and MAX (systolic: r = 0.60 [0.32, 0.78], p < .001; diastolic: r = 0.45 [0.13, 0.69], p = .009). CONCLUSION: The observed correlations between PEH following SUBMAX and MAX, along with their associations with long-term BP reductions, suggest that acute BP changes may partly reflect an individuals responsiveness of resting BP to exercise. 1. Halliwill (2001) 2. Hecksteden et al. (2013) 3. Wegmann et al. (2018)
Read CV Raffaele MazzolariECSS Paris 2023: CP-PN14