Effects of beetroot juice and brief leg blood flow restriction on cycling sprint performance in male college athletes
| ISRCTN | ISRCTN99926648 |
|---|---|
| DOI | https://doi.org/10.1186/ISRCTN99926648 |
| Sponsor | Beijing Sport University |
| Funder | Fundamental Research Funds for the Central Universities and the Chinese Universities Scientific Fund |
- Submission date
- 05/11/2026
- Registration date
- 06/11/2026
- Last edited
- 05/11/2026
- Recruitment status
- No longer recruiting
- Overall study status
- Completed
- Condition category
- Other
Plain English summary of protocol
Background and study aims
The study examined whether nitrate-rich beetroot juice and ischemic preconditioning, used separately or together, affect power during brief maximal cycling exercise.
Who can participate?
Healthy male collegiate track-and-field athletes aged 18–24 years who undertook regular structured training
What does the study involve?
At four visits in a random order at least 7 days apart athletes were allocated to drink either 70 ml of nitrate-rich beetroot juice or nitrate-depleted placebo 150 minutes before testing, together with either three 5-minute thigh-cuff inflations at 220 mmHg (each followed by 5 minutes of reperfusion) or sham treatment at 20 mmHg. They then performed a standardised warm-up, a seated 6-second maximal cycling sprint, and a 30-second Wingate cycling test after 10 minutes of rest. Cycling power and perceived exertion were measured.
What are the possible benefits and risks of participating?
No individual benefit was guaranteed. Temporary cuff discomfort, exertion-related fatigue or soreness, or digestive discomfort were possible. Exercise was supervised.
Where is the study run from?
Beijing Sport University (China)
When is the study starting and how long is it expected to run for?
November 2025 to January 2026
Who is funding the study?
Fundamental Research Funds for the Central Universities and the Chinese Universities Scientific Fund, grant 2025KYPT09
Who is the main contact?
Zhiyu Zhang, zhiyu.sprint@gmail.com
Contact information
Public, Scientific, Principal investigator
School of Strength and Conditioning Training, Beijing Sport University, No. 48 Xinxi Road, Haidian District
Beijing
100084
China
 ORCID ID |
0009-0001-3982-7668 |
|---|---|
| Phone | +86 (0)15635376300 |
| Zhiyu.Sprint@gmail.com |
Study information
| Primary study design | Interventional |
|---|---|
| Allocation | Randomized controlled trial |
| Masking | Blinded (masking used) |
| Control | Placebo |
| Assignment | Crossover |
| Purpose | To evaluate the independent and combined effects of dietary nitrate supplementation and ischemic preconditioning on short-duration cycling performance in trained athletes. |
| Scientific title | Effects of dietary nitrate and ischemic preconditioning, alone and in combination, on early cycling power compared with placebo and sham in male collegiate track-and-field athletes: a randomized factorial crossover trial |
| Study objectives | |
| Ethics approval(s) |
Approved 10/11/2025, Sports Science Experiment Ethics Committee of Beijing Sport University (No. 48 Xinxi Road, Haidian District, Beijing, 100084, China; +86 (0)10 6298 9306; mt5345916@163.com), ref: 2025507H |
| Health condition(s) or problem(s) studied | Short-duration high-intensity cycling performance and neuromuscular power |
| Intervention | An investigator independent of participant testing and statistical analysis generated a computer-based allocation to 24 fully counterbalanced orders of the four conditions in a randomised 2 × 2 factorial crossover study. The 24 randomised participants each completed one of the 24 orders, with each intervention occurring six times in each period. Visits were separated by 7 days. Supplement and conditioning allocations were coded, and participants were blinded to supplement identity and not informed which conditioning protocol was active. Each participant completed four experimental conditions in a randomized order: 1. Nitrate-rich beetroot juice (BRJ) + ischemic preconditioning (IPC). 2. BRJ + sham IPC 3. Nitrate-depleted placebo (PL) + IPC 4. PL + sham IPC The four experimental visits were separated by 7-day washout periods. Dietary supplementation: Participants consumed either 70 ml of nitrate-rich beetroot juice (Beet It Pro Elite Shot, James White Drinks Ltd., UK), providing approximately 400 mg nitrate (6.4 mmol NO₃⁻), or 70 ml of nitrate-depleted placebo 150 minutes before the 6-second cycling sprint. Ischemic preconditioning: Pneumatic cuffs were placed bilaterally around the proximal thighs. IPC consisted of three 5-minute cuff inflations at 220 mmHg, each followed by 5 minutes of reperfusion. Sham IPC followed the same procedure at 20 mmHg. Both procedures were administered approximately 10–40 minutes before the 6-second sprint. Exercise testing: Each visit included a standardized 5-minute cycling warm-up, followed by 5 minutes of passive recovery and a seated 6-second maximal cycling sprint. After 10 minutes of passive recovery, participants completed a seated 30-second Wingate test using a Wattbike Trainer. Participants were blinded to supplement identity and were not informed which cuff pressure represented active IPC or sham. Experimental condition assignments were coded during outcome processing. |
| Intervention type | Mixed |
| Primary outcome measure(s) |
|
| Key secondary outcome measure(s) |
1. Mean power output during the seated 6-second maximal cycling sprint, measured using a Wattbike Trainer and recorded through Wattbike software. Values were normalised to body mass (W/kg). Measurements were performed approximately 150 minutes after supplement ingestion, following IPC or sham intervention. |
| Completion date | 30/01/2026 |
Eligibility
| Participant type(s) | |
|---|---|
| Age group | Adult |
| Lower age limit | 18 Years |
| Upper age limit | 24 Years |
| Sex | Male |
| Target sample size at registration | 30 |
| Total final enrolment | 30 |
| Key inclusion criteria | 1. Male collegiate track-and-field athletes aged 18–24 years 2. Classified as Tier 2 trained/developmental athletes 3. At least 3 years of structured sprint, jump, and resistance training 4. Completed at least five training sessions per week during the competitive season 5. Provided written informed consent before study participation |
| Key exclusion criteria | 1. Cardiovascular, metabolic, neurological, or musculoskeletal disease 2. Lower-limb injury within the previous 6 months 3. Current use of nitrate-containing supplements or other ergogenic aids 4. Medication affecting cardiovascular or neuromuscular function 5. Current tobacco use 6. Regular or excessive alcohol consumption 7. Alcohol intake within 24 hours before testing |
| Date of first enrolment | 10/11/2025 |
| Date of final enrolment | 13/11/2025 |
Locations
Countries of recruitment
- China
Study participating centre
Beijing
-
China
Results and Publications
| Individual participant data (IPD) Intention to share | Yes |
|---|---|
| IPD sharing plan | De-identified individual participant-level analysis data and the accompanying data dictionary will be available from the corresponding author upon reasonable request, subject to institutional ethics requirements, participant confidentiality, and an appropriate data-use agreement. |
Editorial Notes
05/11/2026: Study's existence confirmed by the Sports Science Experiment Ethics Committee of Beijing Sport University.
