The Effects of an Acute Dose of a Betalain-rich Concentrate on Repeated-sprint Cycling Performance and Recovery.

A minimum of 10 recreationally active men and women will be recruited from the Drexel University student population. All eligible participants will report to the laboratory for a total of three visits (one familiarization session, and two testing sessions). Each participant will be randomly assigned to receive the treatment or placebo in a counterbalanced fashion.

Visit 1 will serve as a familiarization session, where all participants will perform the repeated-sprint exercise (RSE) protocol, and the countermovement jump (CMJ) to become acquainted with the exercises. In addition to testing familiarization, baseline characteristics will be obtained (i.e., height, weight, and body composition).

Visits 2 and 3 will serve as the testing sessions. All participants will report to the laboratory in the morning, no earlier than 48 hours after Visit 1, following an overnight fast of at least eight hours before arriving. During the fasting period, participants will be asked to avoid all food and drinks except water, which can be consumed ad libitum. Upon arrival, participants will be given a 10-minute seated rest period, during which they will be fitted with a Polar heart rate monitor to assess heart rate (HR). After the 10 min rest period, participants will receive their designated supplement, and then sit quietly for 20 min. Afterward, participants will be given a standardized snack (Clif Builder's Bar; kcals: 270, fat: 8g, carbs: 30g, protein: 20g) and 500 ml of water, then sit quietly for an additional 100 min.

At 120 min post-treatment, HR, muscle soreness (MS), and rate of perceived exertion (RPE) will be obtained. The participants will then be asked to begin the warmup, which will consist of 10 min of cycling at a resistance of 60 W. Immediately prior to the RSE, all participants will perform three CMJs. Once done, the participants will perform the RSE protocol, consisting of three back-to-back 30-second Wingate tests, each interspersed by 2 min.

After sprints 1 and 2, peak power (PP), average power (AP), fatigue index (FI), RPE, MS, and HR, will be obtained. Immediately following the RSE (i.e., sprint 3), participants will perform the CMJs again, and PP, AP, FI, MS, and HR will be recorded. Final CMJ measures will be taken 5 min following the RSE.

Inclusion criteria

• Healthy, recreationally active males and females
• Aged 18-40
• Free of disease or injury

Exclusion criteria

• Have any musculoskeletal injuries that could be made worse by participating in this study (e.g., sprain or strain of lower limb)
• Have documented medical conditions (i.e., hypertension, asthma, heart disease, diabetes) or exhibit signs and symptoms of medical conditions
• Taking any medication that would interfere with the interpretation of our results. These include, but are not limited to, anti-inflammatory drugs, antibiotics, anti-hypertensives, and any medicine controlling the digestive system.