If I’m anaemic, the oxygen-carrying capacity of my blood will limit the ability of my muscle cells to work, to contract and ultimately it will limit my ability to run.
Runners can store about 2,500kcal in the form of glycogen (i.e. carb) and that will fuel them for about 2 hours of exercise. Even the leanest athlete carries a reserve of about 50,000kcal as fat, however, so perhaps fat adaptation could be a very useful strategy for endurance events.
“I’ve recently fought my way back from an extended period of injury (6 months) where I was not able to train at all, only minimal running.
Now that I’m back do a structured week of training how many potatoes do I need to eat? How much pasta or rice equates to an hour of sub-threshold running?
I’m currently doing an hour of running a day. This mostly consists of sub-threshold runs at about 70% – 80% max heartrate range. I’ll do one race or one VO2 Max session per week ( >90%) followed the next day by a recovery run at 60% – 70%. I average one non-running day per week. I also do one exersise (core strength) class per week.”
Thanks, Laurie, June 2015
The answer to your question depends upon what else you’re eating, because you’ll be getting energy (kcal) from all of your food. Bear in mind, also, that your energy needs and your energy intake will normalise across a week (or any given period), such that you may be ‘catching up’ on your rest day or slightly deficient overall on race day.
In order to answer your question fully, we would have to do a food diary, but I can make a series of assumptions based on weight, height and activity levels. Then, I would calculate the difference in energy requirements between none, little and your actual training schedule.
Mary, Russell-Price Sport & Wellness Nutrition
What’s the best source of energy for runners – carbs or fat?
As with so many apparently simple questions, the answer is: well, it depends…
Not to be confused with ‘train high, compete low’ (which refers to altitude), training with low carbohydrate levels and competing with high levels has been referred to recently as a new strategy. The landmark studies that initiated this strategy are relatively recent and the first of these investigations is known as the ‘one legged cycling’ study….
Recovery after exercise such as running, walking or cycling involves a number of different physiological processes. In the short term (3 to 4 hours) rehydration is the number one priority, so we need water and some electrolytes. The second priority, the replacement of glycogen fuel stores, requires carbohydrate. But what about protein?
Recovery is about restoring glycogen (fuel) stores and muscle protein. After a race or a heavy training session, you will have depleted your muscle and liver stores of glycogen, potentially to quite low levels, and carbohydrate foods are essential in replacing those stores. Even without any overt injury, running causes micro-level damage and a net breakdown of muscle protein. Dietary protein is needed to support the increased rate of muscle protein turnover that will counteract this damage. Continue reading
Your questions related to sport and exercise nutrition, nutritional health and any other topics covered in Russell-Price Sport and Wellness Nutrition’s website can be posted here.
Question from Laurie:
Sometimes when I run I feel good, energetic, but other times I feel very tired and I just want to stop and walk.
What’s going on? What does “tired” mean in this context?
Feeling tired whilst exercising is something that many of us will identify with! The feeling of tiredness suggests that we just don’t have enough energy left in our bodies to fuel that exercise any longer.
From your question, I assume that you run regularly, rather than just once in a while. There are several things to look at when trying to find out what’s going on, as below.
- Are you getting enough sleep? Generally, adults need 6-8 hours sleep each night during which our bodies go into repair mode.
- Are you training very hard or running very frequently? When we step up our training regime, we can suffer from something called ‘over-training’ which will lead to negative feelings and tiredness. It would be wise to review your training schedule and your recovery activities.
- How is your general health and wellbeing? If your body is fighting low level infections or dealing with other stresses, you will have less energy left to fuel your running and you are likely to need longer to recover from each session.
- Whether or not any the points above suggests what may be the root cause of this apparent lack of energy for you, your day to day nutrition is key to providing you with the basis for exercising and for successful training.
A balanced diet, with plenty of carbohydrates, adequate protein, vitamins and essential minerals is essential, on a day to day basis, when you are exercising regularly. Depending upon your schedule, you will need to fuel your body with carbohydrate prior to training sessions and possibly during them too. Also, don’t forget about recovery; you need to replenish those energy stores with carbohydrate as soon as possible after a run.
Please contact me if you would like to explore these questions further.
At this time of year you may be training for a Spring race, perhaps a marathon or a shorter distance. You’ll have a training plan that leads you to increase your mileage and/or put in some speed sessions. If you are increasing your training mileage you’ll need more energy. If you are training harder, and for longer, you’ll be increasing the physiological stresses on your body and you need to take precautions against those stresses having adverse effects on your overall health.