Purpose: To determine the acute effects of a mushroom blend vs. placebo on oxygen kinetics, aerobic power and time to fatigue in healthy adults.

Participants: Twenty-eight, healthy, active, recreationally-trained adults ages 18-35.

Procedures (methods): All subjects will report to the Applied Physiology Laboratory in Fetzer Rm 025 for phase I of the study for a total of 7 visits. A randomly selected subset of 8 participants will continue to phase II, and return to the lab for an additional 3 visits to evaluate feasibility. Visit 1 will consist of a physical, enrollment and consenting. Visits, 2, 3, and 4 will be separated by a minimum of 24 hours. During visit 2, participants will perform a maximal oxygen consumption (VO2max) test on a cycle ergometer. During visit 3 participants will be asked to complete a 6-minute oxygen kinetics test on a cycle ergometer; lactate threshold and oxygen saturation will be measured at baseline, minutes 2, 3 and 6 during the 6 min ride. During visit 4, participants will perform a 3-minute critical power (CP) test and will provide a saliva sample, to be measured for cortisol levels, immediately prior to and after the CP test. Following visit 4, participants will be randomly assigned, in a double-blind fashion, to either a placebo or mushroom blend treatment group. Participants in the placebo and treatment groups will be asked to consume 2 servings, 3 times daily for 7 days. Following supplementation, participants will return to the laboratory for visits 5-7, each of which will be separated by a minimum of 24 hours. The same protocol performed during visits 2-4 will be repeated in the same order for visits 5-7; the VO 2max test, the 6 min oxygen kinetics test, and the CP test with a pre and post saliva sample. The randomly selected subset of 8 participants will continue into phase II (n=4 for treatment; n=4 for placebo). During phase II, the 8 participants in the placebo and treatment groups will be asked to consume 2 servings, 3 times daily for 14 additional days to determine feasibility of a longer supplementation phase. Following supplementation, the same protocol performed during visits 2-4 will be repeated in the same order for visits 8-10, each of which will be separated by a minimum of 24 hours.

Inclusion Criteria:

• Participant has been involved in exercise program for a minimum of one year prior to recruitment (≥ 3 d/wk)
• Participant is able to exercise (i.e. no existing musculoskeletal injury)
• Participant is willing and able to comply with the protocol
• Participant is apparently healthy and free from disease, as determined by a health history questionnaire and physical
• Participant agrees to abstain from smoking, caffeine, tobacco, and alcohol before testing days
• Participant agrees to abstain from exercise 24 hours prior to each testing visit
• Participant is not allergic to mushrooms

Exclusion Criteria:

• Participant has a BMI ≤ 28 kg/m² (pre-screening inclusion)
• Having a history of medical or surgical events that may significantly affect the study outcome, including cardiovascular disease, metabolic, renal, hepatic, or musculoskeletal disorders
• Participant is using, or has used one of the following dietary supplements within 12 weeks prior to enrollment: Beta-alanine, Creatine, Carnosine or Taurine
• Participant has lost or gained greater than ten pounds within the previous 3 month
• Participant is currently enrolled in another clinical trial.
• Participant has a known allergy or sensitivity to any ingredient in the test product or placebo (determined from health history questionnaire)