James Fiedler

Justifying small-n research in scientifically amazing settings: challenging the notion that only "big-n" studies are worthwhile.

if you have ever competed for external research support, you know the drill. Every grant starts with some fantastic ideas that are honed, filtered, and shaped into a grant proposal. Primary aims lead to hypothesis statements, definitions of primary outcomes, and a statistical analysis section. At

The metabolic cost of an integrated exercise program performed during 14 days of bed rest

BACKGROUND Exercise countermeasures designed to mitigate muscle atrophy during long-duration spaceflight may not be as effective if crewmembers are in negative energy balance (energy output > energy input). This study determined the energy cost of supine exercise (resistance, interval, aerobic) during the spaceflight analogue of bed rest. METHODS Nine subjects (eight men and one woman; 34.5 +/- 8.2 yr) completed 14 d of bed rest and concomitant exercise countermeasures. Body mass and basal metabolic rate (BMR) were assessed before and during bed rest. Exercise energy expenditure was measured during and immediately after [excess post-exercise oxygen consumption (EPOC)] each of five different exercise protocols (30-s, 2-min, and 4-min intervals, continuous aerobic, and a variety of resistance exercises) during bed rest. RESULTS On days when resistance and continuous aerobic exercise were performed daily, energy expenditure was significantly greater (2879 +/- 280 kcal) than 2-min (2390 +/- 237 kcal), 30-s (2501 +/- 264 kcal), or 4-min (2546 +/- 264 kcal) exercise. There were no significant differences in BMR (pre-bed rest: 1649 +/- 216 kcal; week 1: 1632 +/- 174 kcal; week 2:1657 +/- 176 kcal) or body mass (pre-bed rest: 75.2 +/- 10.1 kg; post-bed rest: 75.2 +/- 9.6 kg). DISCUSSION These findings highlight the importance of energy balance for long-duration crewmembers completing a high-intensity exercise program with multiple exercise sessions daily.

Last Word on Viewpoint: Justifying small-n research in scientifically amazing settings: Challenging the notion that only “big-n” studies are worthwhile

to the editor: We thank Drs. Bacchetti and Shelhamer (see Ref. [1][1]) for their comments, and we are glad to see they share our opinion that traditional methods and defaults for justifying sample size are overused and underscrutinized ([2][2]). We have become increasingly convinced of this problem

Analysis of Skeletal Muscle Metrics as Predictors of Functional Task Performance: 2895

Performance Jeffrey W. Ryder, Roxanne E. Buxton, Elizabeth Redd, Melissa Scott-Pandorf, Kyle J. Hackney, James Fiedler, Robert J. Ploutz-Snyder, Jacob J. Bloomberg Lori L. Ploutz-Snyder, FACSM. Universities Space Research Association, Houston, TX, University of Houston, Houston, TX, Wyle Integrated Science and Engineering Group, Houston, TX, Syracuse University, Syracuse, NY, NASA Johnson Space Center, Houston, TX PURPOSE: The ability to predict task performance using physiological performance metrics is vital to ensure that astronauts can execute their jobs safely and effectively. This investigation used a weighted suit to evaluate task performance at various ratios of strength, power, and endurance to body weight. METHODS: Twenty subjects completed muscle performance tests and functional tasks representative of those that would be required of astronauts during planetary exploration (see table for specific tests/tasks). Subjects performed functional tasks while wearing a weighted suit with additional loads ranging from 0-120% of initial body weight. Performance metrics were time to completion for all tasks except hatch opening, which consisted of total work. Task performance metrics were plotted against muscle metrics normalized to “body weight” (subject weight + external load; BW) for each trial. Fractional polynomial regression was used to model the relationship between muscle and task performance. RESULTS: The R values for normalized muscle performance versus task performance are presented in the table below. Supine Seat Egress and Walk Object Pick Up and Carry Ladder Treadmill Hatch Opening