The Metabolic and Mechanical Effects of Laddermill vs. Treadmill Maximal Exercise Testing

Abstract

A variety of exercise equipment is now available at most gyms and clinical exercise facilities to increase engagement and participation. Peak Oxygen consumption (VO2peak) is strongly associated with endurance sport performance and reduced all-cause mortality. However, there is a large degree of variability in VO2peak measured via treadmill (TM) or cycle ergometer and other exercise modalities that utilize upper and lower body muscle mass. PURPOSE: To compare the metabolic and mechanical effects of maximal exercise of the laddermill (LM) compared to a standard TM. METHODS: Standardized graded exercise tests were conducted on a LM and TM in 15 healthy, college-aged (22.2+2.4y) men (n=7) and women (n=8) in a randomized, cross-over design. Mechanical intensity (mean G forces) was obtained by tri-axial accelerometers (lateral, vertical, and sagittal; Bioharness, BH3, Annapolis, MD) on the left side of the body. RESULTS: Significant (p<0.005) differences were detected in the peak VO2 between LM and TM exercise (41.5+1.5 vs. 46.0+1.9 ml·kg·-1min-1). While average RER was significantly (p<0.001) different for LM exercise (0.97+.01) compared to TM (0.91+.01), peak HR (188.6+3.7 vs. 189.4+2.8 bpm) and peak RER (1.10+0.01 vs. 1.11+0.01) were not significantly different. LM lactate threshold (4mM) occurred at a significantly (p<0.005) higher percentage of VO2peak 79.3% of VO2peak, vs. TM 73.2% of VO2peak. The corresponding RPE (10.7 vs. 12.2) was significantly (p<0.05) lower in LM compared to TM at lactate threshold. Average mechanical intensity was significantly (p<0.001) lower for LM (0.74+0.09 Gs) vs. TM (3.94+0.33 Gs). CONCLUSIONS: LM exercise elicits a lower VO2peak response than TM exercise at a similar peak HR and RER. The mechanical intensity of LM maximal exercise is considerable lower than TM maximal exercise suggesting a lower risk of developing musculoskeletal injuries.