No abstract

E-bikes may have the potential to improve cardiorespiratory fitness similar to conventional bicycles despite the available power assist, as they enable higher biking speeds and greater elevation gain.

Alterations of retinal vessel diameters are associated with increased cardiovascular risk. We aimed to investigate changes in retinal vessel diameters in response to acute dynamic exercise of different intensities and whether these changes are age dependent. Seventeen healthy seniors (median (IQR) age 68 (65, 69) years) and 15 healthy young adults (median (IQR) age 26 (25, 28) years) first performed a maximal treadmill test (MTT) followed by a submaximal treadmill test (SMTT) and a resting control condition in randomised order. Central retinal arteriolar (CRAE) and central retinal venular (CRVE) diameter equivalents were measured before as well as 5 (t5) and 40 (t40) minutes after exercise cessation using a static retinal vessel analyser. Both exercise intensities induced a significant dilatation in CRAE and CRVE at t5 compared to the control condition (P < 0.001). At t40, the mean increase in CRAE and CRVE was greater for MTT compared to that for SMTT (CRAE 1.7 μm (95 % confidence interval (CI) −0.1, 3.6; P = 0.061); CRVE 2.2 μm (95 % CI 0.4, 4.1; P = 0.019)). However, the estimated difference at t5 between seniors and young adults in their response to MTT compared to SMTT was 5.3 μm (95 % CI 2.0, 8.5; P = 0.002) for CRAE and 4.1 μm (95 % CI −0.4, 8.6; P = 0.076) for CRVE. Wider arteries and veins after maximal versus submaximal exercise for seniors compared to young adults suggest that myogenic vasoconstriction in response to exhaustive exercise may be reduced in seniors. Age-related loss of vascular reactivity has clinical implications since the arteriolar vasoconstriction protects the retinal capillary bed from intraluminal pressure peaks.Electronic supplementary materialThe online version of this article (doi:10.1007/s11357-014-9650-3) contains supplementary material, which is available to authorized users.

Resistance training has been shown to increase arterial stiffness. The purpose of the present study was to examine and compare the systemic arterial stiffness responses to acute lower body (LRT) and upper body (URT) resistance training. 20 healthy young men [median age: 26 years (interquartile range 23, 32)] underwent LRT, URT and whole body resistance training (WRT). Before and immediately after, as well as 20, 40 and 60 min after each training session, we measured the cardio-ankle vascular index (CAVI) and brachial-ankle pulse wave velocity (baPWV) using VaSera VS-1500 N. We used mixed models for repeated measurements to estimate the post-exercise differences in CAVI and baPWV between the 3 resistance training modes. Immediately after exercise cessation, both CAVI and baPWV were lower for LRT compared with URT [CAVI: - 0.93 (95% confidence interval [CI] - 1.15, - 0.70); baPWV: - 2.08 m/s (95% CI - 2.48, - 1.67)]. Differences between LRT and URT gradually decreased during follow-up. Compared with WRT, LRT induced a decrease and URT an increase in arterial stiffness across all time points. In conclusion, LRT presents more favorable post-exercise arterial stiffness than URT. Our results suggest that LRT or WRT may be preferred over URT in individuals with impaired arterial stiffness.

Though not evident at baseline, marathon running was associated with a reduced attenuation of central arterial stiffness in overweight and obese runners. The reduced responsiveness and attenuation of PWV with higher BMI, independent of hemodynamic changes and systemic inflammation, may represent masked vascular dysfunction in overweight and obese runners.