Lower body positive pressure (LBPP) or antigravity treadmills are becoming increasingly popular in sports and rehabilitation settings. Running at a decreased body weight (BW) reduces metabolic cost, which can be offset by running at faster speeds. To date, however, little is known about how much faster someone must run to offset the reduced metabolic cost. This study aimed to develop a user-friendly conversion table showing the speeds required on an LBPP treadmill to match the equivalent metabolic output on a regular, non-LBPP, treadmill across a range of body weight supports. A total of 20 recreational runners (11 males, 9 females) ran multiple 3-minute intervals on a regular treadmill and then on an LBPP treadmill at 6 different BWs (50-100%, 10% increments). Metabolic outputs were recorded and matched between the regular and LBPP treadmill sessions. Using regression analyses, a conversion table was successfully created for the speeds from 6.4 to 16.1 km·h (4 to 10 mph) in 0.8 km·h (0.5 mph) increments on the regular treadmill and BW proportions of 50, 60, 70, 80, 90, and 100% on an LBPP treadmill. The table showed that a greater increase in speed on the LBPP treadmill was needed with more support (p < 0.001) but that the proportion increase was smaller at higher speeds (p < 0.001). This research has implications for coaches or practitioners using or prescribing training on an LBPP treadmill.

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To test the effect of diet on the short-term lipid response to exercise, fourteen moderately trained (VO2max: 50.2 +/- 6.7 ml/kg/min), healthy men (mean age: 28 +/- 4 years) were alternately fed a high fat (60 +/- 6.7% fat) and a high carbohydrate (63 +/- 3.2% carbohydrate) isoenergetic diet for 2 weeks in a randomized crossover design. During the last 4 days of the treatments, fasting total cholesterol, triglyceride, HDL-cholesterol, and HDL3-cholesterol were measured the day before, and again immediately, 24 hr, and 48 hr after exercise (4190 kJ, 70% VO2max). LDL-cholesterol and HDL2-cholesterol were calculated. Lipid concentrations were adjusted for plasma volume changes after exercise. A 2 (diet) x 4 (time) ANOVA with repeated measures revealed no significant interaction between the diet and exercise treatments. Furthermore, diet alone did not influence lipid concentrations in these trained men. Exercise resulted in an increase in HDL-C (10.7%) and HDL3-C (8.5%) concentrations and a concomitant fall in triglyceride (-25%) and total cholesterol (-3.5%). Thus, we conclude that diet composition does not affect the short-term changes in blood lipids and lipoproteins that accompany a single session of aerobic exercise in moderately trained men.

Body weight (BW)-supported treadmill training has become increasingly popular in professional sports and rehabilitation. To date, little is known about the accuracy of the lower-body positive pressure treadmill. This study evaluated the accuracy of the BW support reported on the AlterG "Anti-Gravity" Treadmill across the spectrum of unloading, from full BW (100%) to 20% BW. Thirty-one adults (15 men and 16 women) with a mean age of 29.3 years (SD = 10.9), and a mean weight of 66.55 kg (SD = 12.68) were recruited. Participants were weighed outside the machine and then inside at 100-20% BW in 10% increments. Predicted BW, as presented by the AlterG equipment, was compared with measured BW. Significant differences between predicted and measured BW were found at all but 90% through 70% of BW. Differences were small (<5%), except at the extreme ends of the unloading spectrum. At 100% BW, the measured weight was lower than predicted (mean = 93.15%, SD = 1.21, p < 0.001 vs. predicted). At 30 and 20% BW, the measured weight was higher than predicted at 35.75% (SD = 2.89, p < 0.001), and 27.67% (SD = 3.76, p < 0.001), respectively. These findings suggest that there are significant differences between reported and measured BW support on the AlterG Anti-Gravity Treadmill®, with the largest differences (>5%) found at 100% BW and the greatest BW support (30 and 20% BW). These differences may be associated with changes in metabolic demand and maximum speed during walking or running and should be taken into consideration when using these devices for training and research purposes.

This study investigated the factors related to the perception of stress in EMT’s and paramedics. 144 EMTs and paramedics from urban “third service” EMS providers in Texas completed a questionnaire that included several demographic questions, Speilberger’s (1995) state-trait personality inventory (STPI), Sarason’s (1983) social support questionnaire, and Schwarzer’s (2000) general perceived self-efficacy scale. Six of the eight SPTI measures served as a measure of perceived stress. They were state and trait anxiety, state and trait anger, and state and trait depression. Education was negatively correlated with state anxiety (r=-0.274, p=0.001), state anger (r=-0.217, p=0.009), state depression (r=-0.231, p=0.006), and trait anxiety (r=-0.2058, p=0.014). Since years of education was related to stress and somewhat related to self-efficacy (r=0.17, p=0.042) a partial correlation procedure (controlled for years of education) was performed for self-efficacy (GPSES) and the stress variables. Self-efficacy was negatively correlated with state anxiety (r=-0.312, p=0.0001), state anger (r=-0.194, p=0.021), state depression (r=-0.339, p=0.0001), trait anxiety (r=-0.436, p=0.0001), and trait depression (r=-0.3762, p=0.0001). An analysis of variance was conducted to compare the means of the perceived stress variables for three job function groups (attendant basic or intermediate, attendant paramedic, and in-charge paramedic). Higher perceived stress was reported by both the attendant basic-intermediates and the in-charge paramedics (p