Spinach and other nitrate-rich
vegetables may enhance sports performance, particularly in low oxygen
conditions such as high altitudes, a new study has claimed.
Researchers from the University
of Leuven in Belgium carried out the study with 27 moderately trained
participants. They were given nitrate
supplements ahead of Sprint Interval Training (SIT), which took the form of
short but intense cycling sessions three times a week.
‘Nitrate is commonly found in diets rich in leafy green foods like spinach and is important for the functioning of the human body, especially during exercising.’
To assess differences in
performance in different conditions, the study included workouts in normal
oxygen conditions and in hypoxia conditions, which are low oxygen levels such
as those found in high altitudes.
The researchers observed that
after only five weeks, the muscle fibre composition changed with the enhanced
nitrate intake when training in low oxygen conditions. "This is
probably the first study to demonstrate that a simple nutritional
supplementation strategy, ie oral nitrate intake, can impact on
training-induced changes in muscle fibre composition," said Professor Peter
Hespel from the Athletic Performance Centre at the University of Leuven.
In fact, exercising at high
altitudes has become a training strategy for many athletes, albeit the
uncertainties about such methods. In these conditions, performing
intense workouts requires high input of fast-oxidative muscle fibres to sustain
the power. Enhancing these muscle fibre types through nutritional intake could
very well boost the performance in this type of events.
"Whether this increase in
fast-oxidative muscle fibres eventually can also enhance exercise performance
remains to be established," said Hespel.
"Consistent nitrate intake in
conjunction with training must not be recommended until the safety of chronic
high-dose nitrate intake in humans has been clearly demonstrated," said Hespel.