THE GREEN PAPER: ITCs (ISOTHIOCYANATES)

What are ITCs and how do they work?

Isothiocyanates (ITCs) are naturally occurring compounds found in cruciferous vegetables such as broccoli. The best studied is sulforaphane, which is particularly exciting because of its ability to activate the NRF2 pathway, one of the body's key cellular stress-response pathways.

NRF2 regulates genes involved in the body's own antioxidant defence, cellular protection and response to oxidative stress. Sulforaphane interacts with the KEAP1-NRF2 system, allowing greater NRF2 activity and increasing expression of protective cellular pathways.

For athletes, this could help the body cope with the stress of hard training by supporting its own protective systems, potentially aiding recovery and helping maintain healthy muscle function. Research also suggests that an acute dose of ITCs can reduce blood lactate at the same exercise intensity.

The Evidence: Lower Lactate at the Same Exercise Intensity

Early research suggests ITC-rich supplementation may reduce lactate accumulation at a given exercise intensity and improve exercise tolerance during periods of hard training. Emerging research also suggests sulforaphane may influence mitochondrial adaptation and the body's own antioxidant defence systems.

One of the most interesting human studies comes from Flockhart et al. (2023).

Nine healthy participants completed seven consecutive days of intense interval training in a randomised, double-blind crossover study. During one condition they consumed a glucosinolate-rich broccoli sprout drink twice daily, while the other used a placebo.

Following the broccoli-sprout condition, participants accumulated less blood lactate during submaximal exercise. The lactate curve shifted by approximately 15–20 W, meaning participants could produce more power at the same blood-lactate concentration.

Improved Exercise Tolerance

The same study also measured performance during an incremental exercise test to exhaustion. With ITCs, the average time to exhaustion increased from approximately 380 to 426 seconds.

Supporting the Response to Training Stress

The same researchers found that NRF2 increased after the training period in the broccoli-sprout condition but not placebo. Markers of oxidative stress also moved favourably, including reductions in muscle protein carbonylation and circulating myeloperoxidase.

Oxidative stress is not simply "bad". Some of it acts as a signal that helps drive training adaptation. The potential value of sulforaphane is therefore not necessarily eliminating oxidative stress, but helping the body regulate and respond to it.

The Evidence: What About Mitochondria?

A 2025 study by Champsi and Hood provides another interesting piece of the puzzle. In skeletal-muscle cells, sulforaphane increased NRF2 activity, improved mitochondrial respiration and increased proteins associated with mitochondrial adaptation. It also reduced cellular and mitochondrial reactive oxygen species.

What does this mean for athletes? Mitochondria help turn fuel into the energy your muscles need to keep working. These findings suggest sulforaphane may support some of the processes through which muscles adapt to training, including energy production and the management of oxidative stress.

ITCs and Sodium Bicarbonate?

So where does bicarbonate fit in? ITC research points to lower blood lactate at a given workload, while bicarbonate supports the blood’s ability to buffer hydrogen ions that accumulate during intense exercise and contribute to fatigue.

These are different and potentially complementary mechanisms, with ITCs delaying the onset of lactate and bicarbonate buffering the acidic consequences when you get there!

In a nutshell, ITCs and bicarbonate could offer complementary benefits that help you go further or faster, for the same effort.

How Have We Applied the Science: The ITC Shot

Getting a consistent amount of sulforaphane from broccoli can be difficult. For example, the market leader provides glucoraphanin and relies on its conversion into sulforaphane.

FLYCARB ITC Shot uses standardised sulforaphane, providing athletes with a consistent quantity of active ITCs at the acute dose where lactate reduction is greatest.

The shot comes as a powder in a single-serve format. Add approximately 100ml of water and enjoy what we think is a great flavour (... compared to #BigBroccoli).

We recommend one ITC Shot approximately 3 hours before hard training or racing. Our formulation and protocol reflect the emerging evidence around sulforaphane, while recognising that the sports-performance literature is still at an early stage.