Topics Related to Resistive Exercise Use in Space Why do resorption markers remain elevated while improving bone homeostasis? 1) Why do formation and resorption markers appear to remain essentially uncoupled? Do bone markers represent regional metabolic conditions? 2) Is there a compartmental redistribution of bone with targeted high resistive exercise? 3) How can in-flight resistive exercise be made more efficient/efficacious? 4) Does resistive exercise impact frequency and severity of inflight injuries and ways to prevent? Potential Research Areas Conclusions 1) From a flight risk standpoint, the problem is considered manageable 2) Data show that exercise plus an anti-resorptive will be effective, reducing bone loss, bone resorption and urinary Ca excretion (lowering renal stone risk) 3) Targeted high resistive exercise alone can significantly attenuate bone loss but not necessarily completely