Author ORCID Identifier

Date Available


Year of Publication


Degree Name

Master of Science (MS)

Document Type

Master's Thesis




Kinesiology and Health Promotion

First Advisor

Dr. Haley Bergstrom


Submaximal exercise performance is, in part, limited by the accumulation of metabolic byproducts and energy system capacities. Curcumin and the combination of curcumin and fenugreek soluble fiber (CurQfen®) have been shown to increase endogenous antioxidants and metabolic byproduct clearance as well as reduce inflammation and lipid peroxidation, and therefore, may enhance submaximal aerobic thresholds. In addition, there is evidence that the galactomannan component of fenugreek, used to enhance bioavailability of curcumin, may also have potential physiological effects related to the up regulation of free fatty acid oxidation Therefore, the purpose of this study was to examine the effects of curcumin and fenugreek soluble fiber supplementation on the ventilatory threshold (VT), respiratory compensation point (RCP), maximal oxygen consumption (O2 peak), and time to exhaustion (Tlim)derived from a graded exercise test (GXT). Forty-five untrained, college-aged, male (n = 24) and female (n = 21) subjects (mean age ± SD: 21.2 ± 2.5 yr) were randomly assigned to one of three supplementation groups; placebo (PLA, n=13), 500 mg·day-1 CurQfen® (CUR, n=14), or 300 mg·day-1 fenugreek soluble fiber (FEN, n=18). All of the subjects completed a maximal GXT on a cycle ergometer to determine the VT, RCP, O2 peak, and Tlim before (PRE) and after (POST) 28 days of daily supplementation. The VT and RCP were determined from the V-slope method for the ventilation (E)vs. O2 and E vs. CO2, respectively. Separate, one-way ANCOVAs were used to examine the between group differences for adjusted POST VT, RCP, O2 peak, and Tlim values, with the respective PRE test value as the covariate. The adjusted POST VT-O2 for the CUR (mean ± SD= 1.593 ± 0.157 L·min-1) and FEN (1.597 ± 0.157L·min-1) groups were greater than (p= 0.04 and p= 0.03, respectively) the PLA (1.465 ± 0.155L·min-1) group, but the FEN and CUR groups were not different (p = 0.94). The one-way ANCOVAs for RCP (F = 3.177, p = 0.052), O2 peak (F = 0.613, p = 0.547), and Tlim (F = 0.654, p = 0.525) indicated there were no significant differences among groups. These findings suggested that CurQfen® and/or fenugreek soluble fiber may improve submaximal, but not maximal, aerobic performance indices in untrained subjects.

Digital Object Identifier (DOI)