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The Thames Marathon



Experienced swimmer or not, 14km is a long way to swim. Next month, however, many a hardly soul will be peeling on wetsuits (or swimming in skins…even more hardy!) and jumping gleefully into the Thames to set of on the notorious Henley Swim Thames Marathon, a unique event in the open water swim calendar.

The Thames marathon is the ultimate goal for many water lovers and there is no doubt there is something charismatic about the adventure of pre-training, the event itself and the ensuing recovery period. No matter what your level or experience, preparation is definitely the key ingredient.

Careful thought about training and nutrition is imperative and there is such a fine line between achieving goals and running out of steam over the distance. Correct fuelling is essential and if neglected, the last few miles may be painful!

The main nutrients used to power swimmers over the distance are carbohydrate and fat, with the relative contribution of each depending upon factors such as training status and pace. Carbohydrate is required not only to fuel exercise, but also to restore muscle and liver glycogen levels during recovery.

The week before

The taper period is always met with mixed feelings of joy, frustration and mild panic. However, now is not the time to loose focus. Adequate fuelling the week before the swim is vital, as poorly fuelled muscles cause needless fatigue. The aim of pre-race nutrition is to optimise fuel stores (muscle glycogen) and hydration status. Reducing training load while consuming a high carbohydrate diet (5-8g/kg.bw per day) for 2 days before the race will ensure muscle glycogen levels will be replenished ready for racing. Putting on some weight in this phase is common. Every gram of glycogen stored, holds 3 grams of water, however, don’t be too concerned, this stored fuel will help power you through your race.

My top tips

  1. In the week leading up to the Thames marathon, eating little and often may help you avoid feeling sluggish as a result of reduced training and increase carbohydrate intake.

  2. Try and not eat larger volumes, simply focus on emphasising carbohydrate sources and reducing fat intake. Sports drinks and energy bars can be useful to increase carbohydrate intake without increasing volume too much.

  3. Try to avoid new foods on the day’s leading up to a race as this could lead to disastrous results on the day with extra loo stops on your way down steam.

  4. Those that are prone to bad tummies whilst racing, low fibre carbohydrate sources for 2 days before you race can help reduce pit stops on race day.

  5. On the morning of your race, a light and carbohydrate rich breakfast such as cereal and toast or pancakes with jam will top-up energy stores and ensure enough time is left for digestion.

  6. An hour before the race, topping up with a high carbohydrate snack such as an energy bar or banana will ensure energy stores are maximised. If gut tolerance is an issue, try an energy gel or sports drink in addition to 500ml of fluid to ensure maximum hydration at the start.

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