Physical conditioning to enhance +Gz tolerance: issues and current understanding.

Area of Science:

• Aerospace Medicine
• Human Physiology
• Military Health

Background:

• Canadian Forces (CF) explored G-protection strategies, questioning the impact of physical conditioning (PC) on G tolerance (GT).
• A CF fighter aircraft fatality, potentially linked to "sub-optimal GT," intensified interest in PC's role in G tolerance.

Purpose of the Study:

• To review existing literature on the effects of PC on GT.
• To identify research gaps and determine future research needs regarding PC and GT.

Main Methods:

• A two-part literature review was performed.
• The review surveyed studies on PC's impact on GT and identified areas requiring further investigation.

Main Results:

• G tolerance (GT) is a complex concept with varied interpretations.
• Physical conditioning (PC) lacks precise definitions, hindering comparative research.
• The roles of strength, fatigue, and aerobic fitness in PC's effect on GT are not definitively established.
• PC program design must consider efficacy, palatability, and target population for operational utility.
• Future research needs to control for Gz-stress exposure, anti-G straining maneuver proficiency, and individual variations in PC and GT.

Conclusions:

• The relationship between physical conditioning (PC) and G tolerance (GT) is not well-established.
• More robust research designs and analyses are required to clarify the PC-GT link.
• Conducting such research demands careful planning and significant resources.