Post swim nutrition – the Golden Window

{Apologies for lack of recent of posts. Please bear with continuing intermittent posting.}

One of the sometimes enjoyable aspects of open water swimming and the attendant training is the apparently unassailable appetite. (Sometimes a swimmer’s appetite is a living ting that you struggle to keep at bay. Sometimes you lose).

In exercise, there is a much discussed and much repeated Golden Window, usually quoted as being anywhere from 20 to 45 minutes, post-exercise.

What the chart above means is that for up to about 60 minutes post-exercise, your body is  most sensitive to both protein and glucose, up to 600% and will metabolize both better. This leads to better and quicker recovery and the ability to train consistently without either running into energy deficits or losing muscle mass. In fact, the chart also shows that is you wait too long, over two hours your body will in fact not metabolize food well and this could lead in fact to a net protein loss, meaning reduced muscle mass.

While normally spiking insulin is a bad thing, leading to peaks and consequent troughs of energy that can leave you tired, post exercise insulin sensitivity leads to muscle and liver glycogen restoration and better facilitates protein synthesis for muscle recovery.

Strength athletes love their protein/whey post-exercise shakes but for swimmers we also have to be concerned about glycogen, the muscle fuel we require.  And for glycogen restoration it was found there are better sources depending on time: “Glucose was found to be superior to fructose in rebuilding the liver glycogen stores during the early stages, i.e., the first hour, of recovery after exhausting fatigue, the difference being statistically significant. Fructose approaches glucose in activity in the liver in the second hour, and in the third hour is much more effective than glucose”.

Of course this is just a preamble to talking briefly about food. I used to initially use protein (whey) shakes, but found them too bloating, and making it more difficult to eat properly later on. So I dropped them in favour of natural food, mainly using nuts, chicken or cheese. I got sick of all these when trying to force them down every day. I eventually settled on the simple solution of hot chocolate (or chocolate milk), or a sandwich and glass of milk and maybe some fruit (note the benefits of fructose in the 2nd hour above). Chocolate milk in fact is widely used as a post-exercise food, because of its ideal 3:1 mix of carbohydrate and protein, with science to back up its efficacy. There’s no need to over-think these things and personally I prefer to use natural food over supplements.

{But I still also use a balanced recovery shake after my extra long training swims (>6 hours) and I prefer Irish Company Glanbia’s Provon Revive after a swim friend was involved in the independent lab testing of a number of protein products a few years ago and determined Revive was the best quality product they had tested, and I’m still using up the last stock I bought a few years ago}.

  • Both carbohydrate and glucose powerfully stimulate the release of insulin, your body’s powerful growth hormone.
  • Insulin is needed for both glucose and amino acids to enter cells for glycogen synthesis and protein synthesis.
  • A rapid release of amino acids is critical for signaling of protein synthesis



5 thoughts on “Post swim nutrition – the Golden Window

  1. Pingback: How To: Swim your first pool marathon swimming session (long article) | LoneSwimmer

    • Hi Paul, yes it is. Cow’s milk and soy milk are both 16% protein. Soy milk has 5% carbs whereas cow’s milk is 4%. Sodium & potassium are also similar. Surprisingly fat is double in soy, but in real terms that’s only (6%) vs 3% in cow’s and it’s needed anyway. Soy had no cholesterol. I’ve been meaning to do a quick post on how to make your own chocolate milk also, thanks for reminding me.


  2. “There’s no need to over-think these things and personally I prefer to use natural food over supplements”

    Absolutely – we could not agree more. After a few years adventure racing, I have only use the “goo” and various recovery powders in absolute emergencies when I can’t get to “real food”.

    I would go for a banana or a piece of homemade flapjack every time over some mixed up powder. We think people forget, that our bodies are amazing machines that can run on pretty much any fuel that we put into them – if you think about the variety of diets around the world. Obviously, some diets are going to be “better” than others, but I’m unconvinced that we have found the “perfect diet”… too much of the research is sponsored by companies with vested interests. Everybody is different, and each person will react differently to different foods – the key with nutrition when racing is… experiment in training, find what works for you, stick with that in the race. Simples.


    • Thanks Dan, yes, we agree, I love flapjacks also, should have mentioned them, bananas I also like but discovered for me they don’t work very well when salt water is involved, and can even prompt seasickness which I don’t suffer otherwise. I usually try to keep at least one flapjack in the car in case of emergency. (Only a swimmer would think of not having enough food handy as an emergency).

      As you say, there are too many vested interests in much of these discussions.


What do you think?

Fill in your details below or click an icon to log in: Logo

You are commenting using your account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

This site uses Akismet to reduce spam. Learn how your comment data is processed.