Fuelling Your Body for Exercise with a Chronic Illness

When living with a chronic illness it can be difficult to start and maintain an exercise regime. Eating a healthy, balanced diet can help you to fuel your body correctly to support you in everyday movement. We spoke to Specialist Renal Dietitian, Susan De Waal and Senior Renal Dietitian, Adam Ford from Queen Elizabeth Hospital Birmingham for their expert advice on eating well for an active lifestyle.

Please note: It is important to consult your GP before taking up any new exercise regime or dietary changes.

What does your day-to-day job involve?

“As renal dietitians we support people with chronic kidney disease (particularly those treated with haemodialysis), to manage their condition and ensure they have a good and healthy diet with consideration of the dietary restrictions they may need. It is important for us to help and empower people despite their chronic illness to be able to make the right food choices that support their health and quality of living. Any changes recommended are based on their kidney condition, current treatment they are receiving; their weight, blood results and medications prescribed, as well as considering personal circumstances and what they normally eat and drink. 

“To improve well-being and a healthy way of living we always encourage our patients to be as active as possible. Exercise helps to improve sleep, improve mood, and help keep the body healthy and strong for a better quality of life with more energy to move around, carry out daily tasks and enjoy leisure time.” 

What does a healthy diet look like for most people? 

“A healthy and balanced diet means eating a wide variety of different foods in the right proportions every day. Choosing the right amount of food from each of the food groups helps to provide a wide range of nutrients in your diet. Eating a variety of foods and keeping active can improve general wellbeing, reduce the risk of certain conditions such as heart disease, stroke, some cancers, diabetes, osteoporosis and help manage a healthy body weight.

“Eating healthy and keeping active is just as important for someone with a chronic illness to provide all the important nutrients for the body’s normal functions and may also help reduce symptoms of some health problems. When you have a chronic illness there may be certain foods that you are unable to eat despite them being part of a recommended healthy diet. If you have any medical condition or special dietary needs, speak to your doctor or a registered dietitian for advice to help you make the right food choices.”

“For a well-balanced and healthy diet, you should try to:

  • Eat regular meals, aim to have at least 3 meals a day.
  • Include starchy foods with each meal e.g. bread, potatoes, rice or pasta. Choose wholegrain, or wholemeal type of starchy foods such as brown rice, wholewheat pasta, jacket potato or granary, brown and wholemeal bread. These contain more fibre and usually more vitamins and minerals
  • Eat at least 5 portions of fruit and vegetables every day. They can be fresh, frozen, canned, dried or juiced. Fruit and vegetables are good sources of vitamins and minerals. Try to limit fruit juice to no more than 1 small glass (150ml) a day as fruit juice can be sugary and provide less fibre than fresh fruit 
  • Include good quality protein with each meal for example chicken, fish, egg, beans and pulses and other meats. Protein foods are important for the body to grow and repair itself. Try to eat less red meat and processed meat such as bacon, ham, and sausages. Choose lean cuts of meat and skinless poultry as this will help cut down fat intake
  • Aim to include 2 portions of fish a week, including 1 portion of oily fish whenever possible
  • Have milk and dairy, or dairy alternatives e.g. cheese, yoghurt. Milk and dairy are also good sources of protein and contain calcium which keeps your bones healthy
  •  Choose lower fat and lower sugar products where possible
  • Choose unsaturated oils and spreads such as olive, sunflower, rapeseed or vegetable oils. Only use these fats in small amounts
  • Try to cut down on foods and drinks high in sugar or fat such as cakes, sweets, crisps and sugary soft drinks which are high in calories. Choose low fat or reduced sugar foods if you can tolerate them
  • Drink plenty of water, aim for at least 6 – 8 glasses a day

How does what you eat affect your ability to exercise?

“Food provides fuel (energy) for exercise. If you are missing meals or not eating a variety of foods from all the food groups, your diet may lack certain nutrients that your body needs to provide enough energy for you to exercise. 

“It is important to eat a varied and well-balanced diet that supplies the right amount of energy and essential nutrients. No matter what type of exercise or sport you do, carbohydrates are the most important nutrient for the best performance. Muscles rely on carbohydrate as their main source of fuel during exercise. Foods containing carbohydrate (e.g. starchy foods, fruit) should be included with all meals. The amount you need will depend on your exercise programme. People following a general fitness programme, who are not training to meet a performance goal, can meet their carbohydrate needs by eating a normal healthy diet.

“A diet low in carbohydrate can lead to a lack of energy during exercise, early fatigue, loss of concentration and delayed recovery. In addition to carbohydrates, protein rich foods should also be included in all meals. Protein is required for building and repairing muscles and plays an important role in how the body responds to exercise. Make sure you do not concentrate on a high protein intake only without eating enough carbohydrate; the protein will then be used for energy instead of being used for repair and building of muscle. In general, a healthy and well-balanced diet providing enough energy, will also provide enough protein to meet an increased requirement. Athletes training at higher volumes and intensity typically have greater protein requirements for increased muscle recovery. This specific nutrition should ideally be discussed with a specialist sports dietitian for individualised advice.

“It is also important to ensure you are well hydrated by drinking enough throughout the day as well as before, during and after exercise as appropriate. Dehydration can affect physical and mental performance. Always consider discussing changes in your exercise programme, diet or fluid intake with your medical team and dietitian if you have a chronic illness.”  

What foods should you eat before and after a workout?

“A pre-workout meal should be sufficient to support your body with the nutrients required for the activity. The baseline for this is a varied, balanced diet, but before engaging in physical activity, a high carbohydrate snack or a light meal will ensure sufficient glycogen storage and production to fuel the body. What you choose will be down to time of day and personal preference but should include a good carbohydrate source e.g. bread/rice/potatoes/pasta.

“After exercise aim to have a meal within 2 hours that includes both carbohydrates and a protein source e.g. fish with rice and salad; eggs and beans on toast; chicken salad sandwich etc. Post-exercise carbohydrates will replace glycogen stores and provide energy for recovery, whereas protein will enable muscle tissue to repair and grow. If you are unable to have your meal within 2 hours after exercise, consider having a small snack containing protein and carbohydrate e.g. yoghurt and fruit, oats/porridge with blueberries and strawberries, meat and salad sandwich, almond butter on toast.

“In today’s world there are lots of ‘high protein’ products available in supermarkets, such as yoghurts, milkshakes and rice puddings. These can be very convenient for a handy protein source alongside some fruit for a well-rounded snack. “

What foods are good to eat to build up strength?

“Building strength requires two principles – breaking down muscle fibres through physical exercise (resistance training/weight bearing) and subsequent recovery phase where muscle fibre synthesis takes place (subsequently leading to increasing strength). Similar to the above sections discussing carbohydrate and protein food sources, building strength involves the same elements.

“For most people, consuming a protein source with each meal of the day will provide sufficient protein for building strength, however if you are engaging in significant heavy/intense activities, an additional protein snack between meals may be required and will further support your muscle recovery.”

Can you exercise on an empty stomach?

“We would not necessarily recommend exercising on an empty stomach, although it depends on the individual, the time of day as well as the type of exercise. For gentle exercise there should not be any concerns as long as you eat soon after, however if running a long distance, a light meal or snack is recommended otherwise you may not be able to exercise optimally for very long.”

How soon can you exercise after eating?

“It is suggested to allow at least 1-2 hours after a small meal or snack before exercising, and if a larger meal you may require waiting 3-4 hours. Eating too much before exercise can leave you feeling sluggish or sick. It can be dangerous for example if swimming soon after food and you can get a ‘stitch’, people have drowned this way when unable to stay afloat, so make sure you give a good amount of time before swimming. “

Is there any additional advice you would give to someone with a bladder or bowel condition and who wants to start an exercise regime?

“Anyone with a chronic condition or illness can be more active and do some form of exercise.  To be more active or exercise does not mean that you must join the gym, start jogging or take part in a particular sport. Walking the dog, spending time in the garden or even dancing can be just as beneficial.

“Exercising with friends or family is also a good way of socialising with others. If you are less mobile, you could be advised on where to find appropriate resources to suggest ways to be more active, for example doing strengthening exercises in a sitting position. For those wanting to start a new or a more strenuous exercise programme I would advise to speak to your medical team first to ensure it is safe for you. They may consider a referral to a physiotherapist who can support you with the most suitable exercise programme for your lifestyle.”


Many thanks to our expert dietitians for providing NHS dietary advice when exercising.

There are many, independent published and well researched articles that maybe differ in their advice from standard NHS guidelines. We have added a few more links on this hot topic of food and nutrition, which are more bladder and bowel related.  

We always advocate for the key principles of 

  1. Aim for fresh produce wherever possible 
  2. Always read the label , (the back of the packet NOT the marketing front label) 
  3. Avoid ultra processed foods where possible 
  4. Know the difference between good fats and bad fats 
  5. Keep salt (sodium) to a minimum.

You can find more lifestyle dietary advice for bladder and bowel conditions, stomas and IBS on the Bladder and Bowel Community website.