The Fitness Fixer
The Fitness Fixer

Nutrition for Endurance Swim Training

"Dr. Ernie" is training to swim the Cook Strait of New Zealand. We met him in May in Sixteen Miles of Cold Water, learned about cold acclimatization with him in Getting Fitter in 50 Degrees, and did Better Stretches for Swimming with him in Cook Strait Update.

Dr.Ernie (blog name) writes,

"The water temp now (has risen to) 14 degrees Celsius (57F) and I had a robust swim this afternoon in Wellington Harbour (photo below right). Interestingly enough there was virtually no shivering. I'd swum for about an hour and a half in the pool earlier today.

"I was struck by the difference between pool and ocean swimming... technically I've improved tremendously in the pool over the past few weeks and my times have improved greatly. In the ocean it's much harder -- but I felt faster nonetheless.

"I am not a fast swimmer -- in fact, at this point I am still too slow to pass Phil's test -- but I can feel I'm making progress. I've been able to hold a pace of 2.5 km/hour for a few hours, and this has been an improvement from a measly 2 km/hour not very long ago. And I'll be up to 25 km/week by the end of this month (about 15.5 miles a week - longer and generally more work swimming than running).

"My plan is to increase weekly mileage to 40 km (approx 25 miles) per week by the end of November and then to make a push through to 50 km/week (about 31 miles) by the end of December -- the 'crunch' month. I'll attempt to renter the open waters by mid-November and begin reacclimatization to the cold. With luck and persistence, I'll be granted the privilege of attempting the Cook Strait swim.

"I met with Phil Rush -- the man who has crossed the Strait seven times (including a double-crossing) and who holds the world's record for a triple crossing of the English Channel. He will be piloting the support boat for my attempt, which will hopefully be in February 2008. His advice: swim, swim, swim… then be ready to take a 6-hour test in early January. In the test I will have to demonstrate that I can sustain at least a 3 km/hour pace for the 6 hours. He told me I'd have to figure out the kind of sustenance I'd need on my own, and he recommended that I not try to gain too much weight -- though he cautioned not to lose any from this point on. He also suggested that I procure the skills of a swim coach to refine technique (Fitness Fixer posts in progress on faster healthier stroke mechanics for swimming).

"Any advice on nutrition or cross-training would be appreciated. Because I also have a full-time job, time is tight and hours in the water are limited. I've experimented with a commercial product (name deleted) for multi-hour endurance activities that's easy on the stomach."

I am not a nutrient biochemistry or epidemiology researcher, so I can only report what I have read from others, which can inadvertently repeat and perpetuate wrong information incestuously (we all say so, it must be true). Following is a summary of what I believe and have seen from working with my patients and athletes:

  • In general, good nutrition all year will give more benefit than eating special foods for an event, race, or hike.

  • Processed packaged sports supplement foods cost far more than the ingredients, and you can get healthier ingredients, cheaper, and just as easily without commercial sports powders, bars, drinks, and other preparations.

  • Many nutrients need to work in the original food containing other components that make each part work better. Some do not work, or have even been found to increase health risks when concentrated in vitamin and mineral supplements.

  • In general, no commercial processed "sports food," no matter how engineered or marketed as effective for training, will give you the health of healthful real food. Whole foods, for example, a simple apple with the skin, contain combinations of nutritional and disease fighting chemicals that are not available in supplements.

  • "Energy food" technically means it has calories. Extra calories alone will not enable you to build muscle or win a race.

  • Increasingly, some "energy food" and drinks contain stimulant compounds. This practice is a foolhardy one to become accustomed to, building cycles of inability to focus, exercise, or feel well without them, and varying degrees of agitation with them, sleep difficulties, and various cardiovascular risks.

  • Products with soy are usually unfermented soy. Unfermented soy contains enzyme inhibitors which block digestion, goitrogens which inhibit thyroid function, phytic acid, which blocks minerals like zinc and calcium, and estrogen-promoting compounds. Anyone with tendency to estrogen-dependent tumors or cancer, fibroids, cystic ovary and breast, or endometriosis will be better to avoid unfermented soy.

  • Even if sugar water will extend endurance, it is still junk food, not healthy for the long term. Science Daily reports "Sports drinks face junk food label"

  • Protein and carbohydrate together work better for training than sugar alone, however commercial processed powdered mixtures are still not the healthy choice over the long term.

This is all good news. You can eat good tasting food, that is quick to make, and cheaper and better for you than expensive commercial "sports food."

Don't worry that you have to eat engineered products to be able to win. You will win better in the long run without them.

Related Fitness Fixer:


Photo by Dr. Ernie

  • 1
Was this article helpful? Yes No

About the Author


Dr. Bookspan is an award-winning scientist whose goal is to make exercise easier and healthier.