P

8. Adapted from Nicogossian et al., 1993

10. History of Exercise Countermeasures in the U. S. Space Program Treadmill - excellent for cardiovascular conditioning, minimal effect on musculoskeletal system .

11. History of Exercise Countermeasures in the U. S. Space Program Rubber band devices F = k  x Adapted from Designing Resistance Training Programs, Fleck & Kraemer, 1997.

12. History of Exercise Countermeasures in the U. S. Space Program Penguin suits Adapted from Nicogossian et al., 1993

13. History of Exercise Countermeasures in the U. S. Space Program Isokinetic Dynamometer Adapted from Nicogossian et al., 1993

15. The Constant Force Resistive Exercise Unit (CFREU) - allows for concentric and eccentric contractions - full range of motion - easy weight selection

17. Instruments Leg extension/leg curl device configured for free weights . Leg extension/leg curl device configured for CFREU.

20. Results Percent improvement in 1RM between the CFREU and FW during leg extension. 31.54 13.66 0.00 10.00 20.00 30.00 40.00 Groups Percent CFREU FW

21. Results Percent improvement in 1 RM between the CFREU and FW during leg flexion. 36.57 7.38 0.00 10.00 20.00 30.00 40.00 Groups Percent CFREU FW

22. Results 5 Weeks Leg extension/Leg curl performance variables (mean SD; N = 9) Group CFREU FW Mean SD Increase (%) Mean SD Increase (%) 1 Repetition Maximum (kg) Leg extension Pre 32.36 5.17 43.60 14.21 5 Weeks 41.21 9.37 27.33 46.43 9.37 6.50 Post 42.57 9.16 3.30 49.55 11.38 6.72 Overall Gains 31.54 13.66 Leg flexion Pre 25.43 3.93 38.40 6.10 34.73 5.22 36.57 42.08 6.55 9.60 Post 34.73 6.96 0.00 41.23 4.38 -2.02 Overall Gains 36.57 7.38 * significantly different (p < 0.05) * * *

25. Discussion Pre 5 WK Post 1-Repetition Maximum (kg) 0 10 20 30 40 50 60 Mean (SE) D8855 F2820 M0477 N9336 R7479 Comparison of the individual 1RM to pre, 5 wk, & post training means for leg extension using the CFREU.

26. Discussion Pre 5 WK Post 1-Repetition Maximum (Kg) 0 10 20 30 40 50 Comparison of the individual 1RM to pre, 5 wk, & post training means for leg flexion using the CFREU . Mean (SE) D8855 F2820 M0477 N9336 R7479

27. Discussion Pre 5 WK Post 1-Repetition Maximum (kg) 0 20 40 60 80 Mean (SE) P2493 P2703 S6020 V4415 Comparison of the individual 1RM to pre, 5 wk, & post training means for leg extension using FW.

28. Discussion Pre 5 WK Post 1-Repetition Maximum (kg) 0 10 20 30 40 50 60 Comparison of the individual 1RM to pre, 5 wk, & post training means for leg flexion using FW. Mean (SE) P2493 P2703 S6020 V4415

32.   CFREU Free Weights Knee angle 45  Knee Knee Ankle Ankle Redirect pulley

33. T = Force *  Distance Cos  * Force = Effective Force

34. T = Force *  Distance Cos  * Force = Effective Force

35.   CFREU Free Weights Knee angle 45 

40. Effects of Spaceflight on the Musculoskeletal System (Skeletal Muscle Atrophy) Effects on structure : slow twitch vs. fast twitch Shenkman et al., 1998