Science has confirmed what sports lovers have always known from experience: exercise is good for the brain. It increases blood flow, inhibits stress hormones, and stimulates the release of ‘feel good’ endorphins. One way by which exercise is thought to yield these benefits on the brain is through a chain of processes that ultimately results in the release of the hormone BDNF. Produced by theliver,brain, skeletal muscle, and fat tissue,BDNFis known to promote the growth, survival, and maintenance of nerve cells. Previous studies have suggested that the starting signal for this physiological chain is a high level in the blood oflactate, a by-product of the conversion inside muscle, the liver, and the blood of carbohydrates into energy when oxygen is limited – for example during high-intensity exercise. Now, a study in has found that the physiological benefits of exercise may be partly mimicked by a simple IV infusion of lactate. The authors did a so-called ‘randomized crossover study’ on 12 healthy volunteers aged between 20 and 40 years old. After fasting overnight, these were invited to lie down while either receiving a one-hour long IV infusion of sodium lactate and then, seven to 30 days later, a one-hour long infusion of saline solution; or receiving these treatments in the reverse order. Blood was taken from each volunteer every 10 minutes during both treatments, as well as 15, 30, 45, 60, 90, and 120 minutes afterwards. A leg muscle biopsy was taken before and immediately after each infusion with lactate, as well as 60 and 120 minutes later. The researchers measured the lactate concentration in each blood or muscle tissue sample. They further quantified the levels of pro-BDNF, a biologically active precursor molecule of BDNF, in addition to its mature molecular form mBDNF, in blood plasma, serum, and platelet-poor plasma – that is, plasma from which most platelets have been removed. The authors concluded that IV infusion with lactate is sufficient to boost the levels of pro-BDNF in the bloodstream, but without affecting those of mBDNF. In other words, lactate infusion alone is enough to mimic some, but not all, of the physiological effects of high-intensity exercise. It is expected that such an increase of pro-BDNF will have similar beneficial effects on brain health, irrespective of the mechanism behind it. Ref:Roja J, Ameller N F et al. Lactate infusion increases circulating pro-brain-derived neurotrophic factor levels in humans; Front. Cell. Neurosci., 23 Sept 2025; Sec. Cellular Neuropathology; Vol 19 : https://doi.org/10.3389/fncel.2025.1644843