Diet and Exercise Performance

Scott Jurek, ultra marathon runner

Anyone interested in the link between food and exercise performance might like to listen to Radio 4’s Food Programme.  They’ve just completed a two-part series, Eating To Run (links to both parts below), looking at the importance of diet to running performance.

In Part 1 of Eating to Run, we hear from Kevin Currell, Head of Performance Nutrition at the English Institute of Sport, to find out about the dietary advice given to Britain’s elite athletes. Compare this to the support Brendan Foster was given on performance nutrition in the 1970s – worlds apart!

Adharanand Finn, author of Running with the Kenyans, shares his insights into running, racing and eating in Iten, the town where many of the world’s most successful distance runners live and train. Kenyan runners eat a lot of ugali, a carbohydrate-rich porridge made of maize flour and water.

Elsewhere however, others argue that a low-carb, high-fat diet will help runners achieve peak performance. Author of Born to Run and Natural Born Heroes, Christopher McDougall, profiles diets based on this principle, that fuelled long runs by resistance fighters during the Second World War and early Iron Man events in the 1980’s. It’s a controversial approach and many believe it’s just the latest food fad to be picked up by people in the running world.  But does it work.  The presenter puts it to the test.

Female runner

In Part 2 of Eating to Run, ultra-marathon champion and vegan, Scott Jurek explains how to eat and run 100 miles. The benefits of fermented food and Paleo diets are also considered in depth.

Below is an interesting video of Scott Jurek talking about the importance of plant protein, breathing, posture and relaxation to good running performance.

“Think of running as controlled falling.” – I love that!

Inside Health Exercise Special

street art

Radio 4’s Inside Health returned for a new series last week with a special edition on exercise.  There were some interesting findings, which may be of interest to anyone who is trying to be more active, or to those who already exercise on a regular basis.  If you’d like to listen to the half-hour programme, you’ll find it here.  Not enough time?  The key points from what was discussed are summarised below:

  • According to Philip Conaghan, Consultant Rheumatologist and Professor of Musculoskeletal Medicine at the University of Leeds, weak muscles rather than damaged joints are behind many aches and pains. Generalised joint pains are common.  Often they’re the sort of pains that give five to 10 minutes of morning stiffness that gets worse as the day goes on, so the more you load your joint the more pain you get.  These are termed mechanical joint pains. The root cause of a lot of that pain could be some joint damage, but for most people it’s muscle weakness driving the pain.  Muscle loss can lead to the tendons in the joints overworking, which in turn can result in tendonitis.
  • There is excellent trial evidence that proves muscle strengthening reduces joint pain.  It’s not so important what exercise you do, so long as you’re doing something.  When you’re very weak it’s best to start with just one or two things you can do every day for 30 or 60 minute bursts.  Exercises to strengthen muscles are highly beneficial in alleviating mechanical joint pains.  You can rebuild muscle at any age, but it’s not a quick fix.  It takes time and regular exercise.
  • People are often concerned they will damage their joints faster if they exercise. They are worried about the pain they experience when they exercise.  Conaghan recommends getting strong first to avoid damaging the joints.  For example, lying flat, doing straight leg raises or using a squeeze ball to strengthen your forearm, won’t damage the joints.  He says it will hurt when you start doing it, but muscles ache after they do appropriate exercise and that’s the sort of ache we’re looking for. When you get a bit stronger low weight bearing exercises should be added.  So, for example, for very weak patients, walking laps in a swimming pool is highly beneficial – it’s non weight bearing and it’s fantastic exercise for the lower limb muscles.  Then as you get stronger you might move to an exercise bike or a cross-trainer where the impact is very low.
  • True arthritis pain in the joint may not be reversible, but will still reduce a significant amount with muscle strengthening.

Alex Soth

  • Being weak and out of shape doesn’t just affect how you feel, it can influence your chances of recovery from serious illnesses like cancer.  There were concerns previously that if you’re unwell you should rest and that will help you recover, but studies have demonstrated that exercise has a protective effect against at least four different types of cancers.  Movement, exercise and mobilisation early after either surgery for cancer, or during treatment has been shown to improve your long term outcome.
  • Dr Denny Levitt, Consultant in peri-operative medicine and critical care at the University Hospital Southampton cited a recent study which suggested that about 10% of post-menopausal breast cancer in Australasia could be attributed directly to physical inactivity, i.e. one tenth of the cases of breast cancer can be related to being inactive.
  • World Health Organisation and UK government guidelines suggest that we should be doing around 150 minutes of moderate intensity exercise each week.  Moderate intensity exercise would be going for a brisk walk or a cycle ride.  You should try and do this in bouts of exercise of around 30 minutes, so five times a week, 30 minutes of exercise.  Alternatively with high intensity or strenuous exercise such as running or playing a game of football, only 75 minutes of exercise a week would be sufficient to reduce your health risks.
  • Sanjay Sharma, Professor of Clinical Cardiology at St George’s, University of London says, for joggers and runners, the sweet spot for maximum reward in return for minimum effort –  in cardiovascular terms at least –  lies around training for about 2-2.5 hours a week, at speeds ranging from 15 minute miles, to around eight minute miles for faster athletes.
  • The NHS Couch to 5K app is a useful way to get non-runners into running.  The app takes you from being able to walk and not go very far to being able to run a 5K race.
  • A study suggests that people in the UK aged between 65 and 74, only 20% of men and 17% of women are getting enough exercise.  That falls after the age of 75 to only 9% of men and 6% of women.
  • There are some excellent studies looking at the effects of exercise in elderly frail people.  They suggest that exercises concentrated on strength, balance and some weight training, as well as walking activities, help to improve mortality rates, as well as cutting down on the number of falls.

Old lady stretching



Exercising When You Feel Under the Weather – Help or Hindrance?

Strength training for runners

Everybody feels unwell at some point in their life. The key question is, should you rest until you feel better, or would exercising help your body get back to full health quicker? This news piece, based on an article by Ryans Andrews at Precision Nutrition, aims to answer that question. If you want to skip the science bit and cut to the chase, scroll down to the conclusion section at the bottom of the piece.

The Immune System

Every day we’re confronted by bacteria, viruses, fungi and parasites. The most common are the upper respiratory tract invaders, or URTI’s, i.e. colds, coughs, flu, sinusitis, tonsillitis, throat infections and middle ear infections.

When faced with these invaders the immune system works hard to defend the body. Immune cells originating in the bone marrow and thymus, interact with invaders through the lymph nodes, spleen and the mucus membranes in the mouth, gut, lungs and urinary tract.

The Innate and Adaptive Immune Response

Our innate or natural immune system is our first line of defence. It includes:

• physical/structural barriers like the mucus lining in the nasal passages,
• chemical barriers e.g. stomach acids, and
• protective cells like the natural killer or NK cells, i.e. white blood cells that destroy harmful invaders.

Women tend to have a stronger overall innate immune response, which is probably why they often suffer less than men when it comes to colds.

The adaptive immune system is a more sophisticated system, composed of highly specialized cells and processes, which kick in when the innate immune system is overcome. The adaptive immune system helps us fight infections by destroying bacteria and viruses and preventing them from colonizing.

T and B cells are specialized white blood cells, which have a kind of memory. This enables them to “recognize” a specific disease, and mobilize effectively to fight against it. This is what we mean when we talk about “building immunity.” The reason children catch viruses more often than adults is because they haven’t had as much exposure to diseases so their adaptive immune system is less mature.


How Exercise Affects the Immune System

A structured workout routine – one where you’re breathing heavily, sweating, working hard and feeling some discomfort – awakens a stress response in the body. When we’re healthy, our bodies can easily adapt to this stress. Over time, this progressive adaptation is precisely what makes us fitter and stronger. However, when we’re ill, the stress of a vigorous workout can be more than our immune system can handle.

For those in good shape, non-strenuous exercise with minimal heart rate elevation, e.g. Pilates, walking, going for a leisurely bike ride, gardening and T’ai Chi, isn’t intense enough to create serious immune-compromising stress on the body. In fact it’s been shown to boost immunity.

Scientific research on exercise habits and influenza found:

• People who never exercised got ill quite often.
• People who exercised between once a month and three times a week did the best.
• People who exercised more than four times a week got sick most often.

In other words, being sedentary or exercising too much can lower immunity, whereas somewhere in the middle can actually improve immunity.

La Promessa by Matteo Pugliese

The Role of Stress

Exercise isn’t the only factor affecting the immune system. Stress plays a big role too. Here are the different stressors a person might face on any given day:

• Physical stress – playing sport, physical labour, infection, etc.
• Psychological stress – relationships, career, financial, etc.
• Environmental stress – hot, cold, dark, light, pollution, noise, altitude, etc.
• Lifestyle stress – diet, alcohol, smoking, hygiene, etc.

Stress affects hormone levels, which can result in chronic changes to the immune system. So, if you’re angry, worried, or scared every day for weeks, months or even years at a time, your immunity is being compromised and you’re more likely to become ill.

If you’re unwell and fighting an infection, your immune system is under stress. If you then include the additional stress of prolonged vigorous exercise, you might overload yourself, which is likely to make you even more unwell.

Sudden increases in exercise volume and/or intensity may also create additional stress, potentially allowing another virus or bacteria to take hold, resulting in further ill health. This seems to work the opposite way too, with chronic infections potentially being a sign of overtraining.

Other Factors Affecting Immunity

Besides stress, there are a number of other factors that can affect our immunity, and these combined with excessive exercise may increase the likelihood of us falling ill:

• Age: Our innate immune response works progressively less well as we get older. However, staying physically active and eating a nutritious diet can offset many of these changes.

• Gender: Menstrual phase and oral contraceptive use may influence how the immune system responds to exercise. Oestrogens generally enhance immunity while androgens can suppress it. This may explain why women tend to do better with colds than men.

• Sleep: Poor quality sleep and/or prolonged sleep deprivation jeopardize immune function.



Based on the above findings, potentially helpful activities to do when you’re under the weather are walking, Pilates, jogging, swimming, cycling, Qi gong, T’ai Chi and yoga. All of these activities are low intensity and involve minimal heart rate elevation. Ideally they should be done outdoors in mild temperatures and fresh air. Inside is fine though if you can’t get outside.

Activities to avoid when you’re feeling unwell are heavy strength training, endurance training, high intensity interval training, sprinting or power activities, team sports and exercise in extreme temperatures.

If you feel healthy and want to avoid becoming ill, try and stay moderately active most days of the week. If you take part in high intensity workouts, be sure to allow enough time to rest and recover. In addition, try to manage extreme variations in stress levels, get plenty of sleep, and wash your hands.

If you are already feeling unwell, let the symptoms be your guide as to how much to exercise. With a cold or sore throat (no fever or body aches and pains), low intensity exercise should help your recovery. Vigorous activity, no matter how long in duration is best avoided. If you have a systemic illness with a fever, elevated heart rate, fatigue, vomiting, diarrhoea, muscle and joint pain or weakness, and enlarged lymph nodes, you’re advised to just rest.

When you start to feel better, ease back into exercise in proportion to the length of time you were unwell, i.e. if you were sick for three days, take three days to ease back in.