On a winters day in Sydney – clear blues, 23 degrees and an ocean temp of around 20, what better subject than the sunshine vitamin – our friend ‘D’.
A vital vitamin for:
- bone health and growth
- hormone production (anabolic – growth hormones, testosterone & oestrogen; catabolic – adrenaline, cortisol)
- potentially helping prevent certain cancers (breast, colon, prostate)
- playing a role in healthy heart health, specifically blood pressure.
However, it’s role in performance is of particular interest to me. Studies in athletes have shown vit D:
- helps improve VO2max levels
- stops decline in haematological levels of haemoglobin and haematocrit (circulation of red blood cells and oxygen to muscle cells and therefore efficiency and strength)
- attenuates inflammatory markers, showing a potential role in faster muscle recovery after high intensity exercise
- increases force and power output of skeletal muscle tissue through a biochemical process that sensitises the muscle for force production and contraction
- plays a critical role with anabolic and catabolic hormones, vital in training and performance for muscle adaptation, strength and power output.
Interestingly, vit d levels in much of our population is low – even at the end of summer – due to the efficiency of the sun protection campaigns. Whilst protection from high levels of UV is important, getting decent levels of sun exposure in the safer times of day (before 11am and after 2pm in the winter months) is also important for your vit D as much of it is synthesised by the action of sunlight on your skin.
Getting tested at the end of summer/beginning of winter is important to ensure your levels are in a good place to sustain you through winter as days grow shorter and the yellow globe becomes a little more elusive.
Supplementation under guidance and increasing your intake of vit D foods are both easy actions to take.
Good concentrations of vit D can be found in foods such as:
- fish liver oils – cod, salmon, tuna
- egg yolks
- sprouted seeds
- beef liver
Supplementation, where needed, will vary on your individual levels and your requirements for training and competition.