Cutaneous vascular responses to isometric handgrip exercise.

Area of Science:

• Exercise Physiology
• Cardiovascular Physiology
• Cutaneous Circulation

Background:

• Cutaneous vascular responses to dynamic exercise are well-documented.
• The effects of isometric handgrip exercise on cutaneous blood flow are less understood.
• Understanding these responses is crucial for comprehending thermoregulation during exercise.

Purpose of the Study:

• To investigate cutaneous vascular responses to isometric handgrip exercise.
• To compare these responses with those during dynamic leg exercise.
• To determine the influence of local skin temperature on these responses.

Main Methods:

• Five healthy men performed isometric handgrip and dynamic leg exercise while supine.
• Skin blood flow was measured using laser-Doppler velocimetry (LDF).
• Cutaneous vascular conductance (CVC) was calculated as LDF divided by mean arterial pressure.

Main Results:

• Isometric handgrip at 30% maximum voluntary contraction increased forearm LDF and CVC, particularly at a local skin temperature of 39°C.
• Arm LDF increased by 64.8% and CVC by 18.1% during handgrip at 39°C (P<0.05).
• Dynamic leg exercise at 39°C caused a decrease in arm LDF (-12.2%) and CVC (-35.3%) (P<0.05).

Conclusions:

• Isometric handgrip exercise, especially with elevated skin temperature, enhances cutaneous vascular conductance in the exercising limb.
• Dynamic exercise elicits a contrasting response, reducing cutaneous vascular conductance in non-exercising limbs.
• These findings highlight distinct vascular control mechanisms during different exercise types.