Timing of Broccoli Sprout Intake to Improve Exercise Performance

Condition(s) studied

Investigational drug(s) / intervention(s)

Broccoli sprout drink (isothiocyanate-rich: Active intervention is a drink prepared from broccoli sprouts (50 g per dose) as a natural source of glucosinolates/isothiocyanates (ITCs). Participants ingest the drink either \~16 hours before the exercise session (evening prior) or \~3 hours before the exercise session (test day morning), depending on randomized condition. The study compares the timing of ITC intake versus placebo, with identical procedures across conditions.

Placebo drink: The placebo intervention is a drink prepared from alfalfa sprouts (50g per dose) as a placebo. Participants ingest the drink at both \~16 hours before the exercise session (evening prior) and \~3 hours before the exercise session (test day morning). The study compares the timing of ITC intake versus placebo, with identical procedures across conditions.

Study summary

This study examines how the timing of intake of a broccoli sprout-based drink (a natural source of isothiocyanates, ITCs) affects physiological responses, recovery, and performance after a standardized endurance cycling session. Healthy, endurance-trained adults (18-64 years) will complete four laboratory visits at the Swedish School of Sport and Health Sciences (GIH): one screening/physiology test visit and three intervention visits in a randomized, double-blind, placebo-controlled cross-over design. On intervention visits, participants will ingest either an active broccoli sprout drink (50 g sprouts) or a placebo drink based on alfalfa sprouts (50 g sprouts) according to randomization. The drink will be consumed either approximately 16 hours before exercise (the evening before) or approximately 3 hours before exercise (the morning of the test), enabling comparison of timing in relation to a standardized \~2-hour cycling protocol (individualized intensity) followed by a 10 km cycling time trial. Outcomes include measures of performance, heart rate, perceived exertion and recovery, blood glucose and lactate, and metabolic responses. Venous blood samples are collected at multiple time points before and after exercise and during the subsequent laboratory recovery period, and muscle biopsies are obtained at defined time points to assess muscle metabolism and recovery-related markers. Participants return \~24 hours after exercise for follow-up sampling after an overnight fast, including a glucose tolerance test

Eligibility

Primary outcome measure(s)

• Lactate — During exercise and across the 0 to 8 hours recovery period (hourly venous samples), and at the follow-up, approximately 24 hours post-exercise.
  blood lactate (mmol/L) at predefined time points during exercise; venous sampling schedule as per protocol.
• Glucose — During exercise and across the 0 to 8 hours recovery period (hourly venous samples), and at the follow-up, approximately 24 hours post-exercise.
  Blood glucose (mmol/L) at predefined time points during exercise; venous sampling schedule as per protocol.
• Glycogen — Before exercise, immediately post-exercise, 8 hours post-exercise, and 24 hours post-exercise
  Muscle glycogen content in the vastus lateralis obtained from biopsies at pre-exercise, immediately post-exercise, 8 hours post-exercise, and 24 hours post-exercise to quantify glycogen depletion during exercise and repletion during recovery

Trial sites (1)

More The Swedish School of Sport and Health Sciences trials in Sweden

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