Exercise - the right sort
Exercise must be the right sort to give benefit
Humans, along with all other mammals, evolved living physically active lives. This usually meant long hours of sustained activity, but there would be occasions when maximal energy-output was needed, for example, to fight an enemy or bring down a prey. It could be argued that most internal metabolism is geared towards physical activity and without this we cannot be fully well.
One needs exercise as one needs food and water: in just the right amount. Too much risks injury and muscle damage; too little and we degenerate. To maintain optimal fitness, we need steady sustained exercise combined with outbursts of extreme energy. Just as with food, the type of exercise and the amount is critical. After research and practical application, Dr Doug McGuff and John Little, produced their book “Body by Science – a research based programme for strength training, body building and complete fitness in 12 minutes a week”. Thanks to their work, we can now see how to exercise most efficiently. We do not want to do so much that we wear out our body (this is what happens with so many athletes – most runners are carrying injuries!) but when we do exercise it must be effective to improve cardiovascular fitness. What is so interesting about Little & McGuff’s approach is how well this correlates with what we already know about mitochondria, blood sugar control and fats.
This approach makes perfect evolutionary sense. I do not see badgers and foxes trotting round my hill every morning to get fit! Most of the time wild animals are in hiding or feeding quietly. Once a week there will be a predator-prey interaction - the predator must run for his life to get his breakfast, the prey must run for his life! In doing so both parties will achieve maximal lactic acid burn. This is all that is required to get fit and stay fit.
The underlying principles
We are taught that there are two types of fitness viz. muscle power and cardiovascular fitness. Not so. What drives cardiovascular fitness is muscle strength. When muscle strength is used to its full capacity, it creates a powerful stimulus to the energy supply mechanism. This includes mitochondrial function and heart function. The heart pumps blood to send fuel and oxygen round the body where is it picked up by mitochondria who convert that to ATP, the currency of energy in the body. See CFS - The Central Cause: Mitochondrial Failure. This means that if muscle strength is correctly developed, this automatically translates into cardiovascular fitness and increased numbers of mitochondria. More mitochodnria means better cardiovascular fitness. Most importantly, McGuff has an excellent research base to show only 12 minutes a week is needed to achieve this.
What this means is that cardiovascular fitness IS THE SAME THING as mitochondrial fitness. Getting fit is actually about supplying the right stimulus to mitochondria to get them geared up to speed amd to increase their numbers. If the mitochondria can supply the energy then the muscle can work at a high level and maintain that.
How does exercise impact on mitochondria?
McGuff discusses in great details the mechanisms by which exercise stimulates mitochondria. We start with the muscle itself
The body has to gear its energy use very carefully to work load in order that energy is used most efficiently. To achieve this there are four types of muscle fibre. On the one hand we have slow twitch, on the other fast twitch with intermediate fibres between the two.
Slow twitch fibres – these are used when power demands are low. This makes them very efficient, they use small amounts of energy, give good endurance so we can use them for a long time, they are rather weak fibres but are slow to fatigue and quick to recover. There are the fibres we use for pottering about when we do not need much power.
If we work a bit harder we start to recruit intermediate twitch fibres.
Fast twitch fibres – these are employed when power demands are high. They occupy much more space and give us big muscles, they require a lot of energy to cope with high power demands, they fatigue very quickly and take a long time to recover once fatigued.
What happens when you start to use the muscles – Recruitment
The brain controls whether slow twitch or fast twitch fibres are used. It wants energy to be used in the most efficient way with quick recovery. So initially it employs the slow twitch fibres. If the power demands are low, these fibres stay in use. Energy supplied from the blood stream is sufficient. This is what we do when we potter. The trained athlete can run very efficiently just using slow twitch fibres. These people are thin with smallish muscles. They make the best long distance runners.
If the power demand increases, the brain also starts to recruit the fast twitch fibres. This requires much more energy to cope with the power demand and energy stores within the muscle, i.e. glycogen stores are quickly used up. These athletes are the sprinters and weight lifters – they have large powerful muscles. Actually these people are much healthier than the long distance runners!
Strong fast twitch muscle fibres give you huge metabolic benefits
- During power exercise, glycogen in the muscle is used up. This is excellent news! Sugar is the petrol of the engine - highly necessary but highly dangerous. When blood sugar levels rise after a meal the best sponge for mopping it up is muscle glycogen. Normally this is depleted by exercise - but without exercise, glycogen remains saturated, blood sugar levels spike and the hypoglycaemia roller coaster is triggered.
- This means when blood sugar levels peak after food, the sugar is shunted into muscles and liver and converted to glycogen. Insulin sensitivity is restored (in diabetes there is insulin resistance).
- If glycogen stores are never depleted, then sugar gets shunted into fat instead. This means carbohydrate consumed results in fat (obesity) and the formation of the bad cholesterol LDL. This suggest that high levels of LDL are symptomatic of the wrong sort of exercise and so poor mitochondrial function and so poor cardiovascular fitness.
- Depleting glycogen activates hormone sensitive lipase so that fats are mobilised from body stores and made available for energy supply. This is very helpful for the dieters who get stuck!
- If sugar in the blood stream following a meal cannot be taken up because glycogen stores are full, then this excess sugar sticks on to other things creating Advanced Glycation End-products or AGEs – they literally accelerate the normal ageing process. One such example is glycosylated haemoglobin which is measured to assess blood sugar control in diabetics.
Good fast twitch fibres = good mitochondrial function = good cardiovascular fitness
The right sort of exercise (see below) creates a demand for energy. Initially this comes from Krebs citric acid cycle which is anaerobic (without oxygen) and provides pyruvate for oxidative phosphorylation. In this scheme, KCA provides 2 molecules of ATP and happens very fast. Oxidative phosphorylation is slower to get going but provides 36 molecules of ATP! If energy demands increase (see below) too much pyruvate is supplied and spills over into lactic acid. This gives us our lactic acid burn, makes exercise uncomfortable and makes us want to stop! This, of course, is part of how the body conserves energy – without this burn we would spend energy mindlessly, rapidly lose weight and not survive.
But the important point about lactic cid is that it provides a powerful stimulus to our energy supply system – that means mitochondria and heart function ie cardiovascular fitness. More mitochondria mean bigger muscles (each heart cell has 2,000-3,000 mitochondria occupying most of the cell!). Big muscles mean lots of mitochondria means good cardiovascular fitness.
It really is a case of "no pain no gain", but the good news is with correct exercise the pain is only short lived.
So what sort of exercise?
To increase muscle bulk and improve cardiovascular fitness one needs to do the right sort of exercise.
- The exercise has to be very slow but powerful – this prevents damage to muscles and joints.
- It must be sufficiently powerful so that initially the slow twitch fibres are used, but towards the end of the exercise all the fast twitch fibres are being used. If the exercise is not demanding enough then only the slow twitch fibres will be used – so no gain!
- The window of time to exercise a group of muscles needs to be 45-90 seconds.
- At the end of this window, the muscles being worked must be burning with lactic acid and weak – that is to say the exercise cannot be sustained any longer. This means your fast twitch fibres have all been fully employed and exhausted. This provides the maximum stimulus for improved energy supply (and therefore cardiovascular fitness) and enlarging muscles. Since over half of muscle weight is mitochondria, big muscles mean more mitochondria. What makes muscles fatigue is not lack of muscle filaments, but inability to supply energy to them. When body builders show off their muscles, actually they are showing off their mitochondria!
The slow twitch fibres will recover quickly so after a few minutes you will be able to function normally, but you could not repeat the power exercise you have just done. If you could, then you have not done enough! If you did repeat the exercise, you would just cause excessive muscle damage.
- This mild muscle damage is a powerful stimulus to create more mitochondria.
- After exercising a group of muscles, they must be rested for a week (ie stay within slow twitch capabilities). This allows time for healing and repair to upgrade mitochondria, make more mitochondria and better functioning fast twitch muscle fibres.
- There is no gain to be had by repeating these exercises more often than once a week – the heart and mitochondria only need one good kick to upgrade their performance. Indeed, repeat exercises are likely to be counter-productive by causing too much tissue damage.
Remember wild animals are all super fit - but most of the time they are pottering about gently or hiding. It is only occasionally that either the predator has to put in a powerful burst of activity to catch his prey, and this is matched by a similar burst in the prey. This is how Nature keeps them fit!
What are the actual exercises?
McGuff recommends five exercises to use for five different muscle groups. Do each exercise very slowly – it is not the number of times that is important but the power used. You should experience gentle increasing muscle pain until you are forced to give up at 45-90 seconds. At this point the muscle will be so weak you cannot continue (this prevents tendon and muscle damage). You will also puff and pant and your heart will go faster – that is OK too! McGuff does use a machine – you will have to get the book (or look on You Tube Body by Science presentation by Dr McGuff) to see exactly the exercises, but they are:
- Seated row
- Chest press
- Pull downs
- Overhead press
- Leg press
- Each exercise is done for 45-90 seconds, which is how he arrives at 12 minutes a week!
- Each exercise is done very slowly – you may only do 4 or 6 repeats of each movement.
- You will puff and pant by the end of the exercise. This reflects oxygen consumption.
- Each exercise must be done to the absolute limit of your ability, until the muscle weakens under the strain. It is very painful - but it does not last long! This means no injury to joints and ligaments! You have to work out through experience how much is right for you, but this will increase with time as you become more powerful. This can be done on the machine by increasing the weights. With age we expect to lose muscle mass and cardiovascular fitness – this therefore slows the ageing process.
Exercises with free weights - less fancy equipment!
The exercises are:
- Bent over barbell – raising barbell from floor to hips using arms (slight bend at knee)
- Standing overhead press – raising barbell from shoulders to above head with arms
- Dead lift – raising barbell from floor to hips using legs
- Bench press – lying on the floor and pushing barbell up off you body
- Squat – barbell across shoulders and neck, squat and stand alternately.
Again the weight of the barbell can be adjusted so that you work to the limit of your ability. This will increase with time. If you do not work to your limit there is no gain.
Exercises with no fancy equipment
Thank you to one of my patients, Dan Grey, for designing a set of exercises which can be done with no special equipment in your own home! Have a go! Exercises – the big four which take 12 minutes to do!
Most people are not exercising the most efficiently
Increasing fitness of the body takes place early on when you start exercising – i.e. in the first 45 to 90 seconds. If you continue to exercise beyond this, without increasing the work load, then all you are doing is risking injury and wearing out the body. It’s fine to continue if you are enjoying yourself, but a waste of time if you are going through the motions in a misguided attempt to get fitter!
What people call “aerobic exercise” is not achieving much! It is the initial getting up to speed which stimulates increasing fitness. Once you have got your “second wind” (and I believe this is a symptom of mitochondria having geared up to speed so they are running smoothly), exercise becomes fairly effortless, but is not achieving additional fitness –it is just wearing out the system. Fine when you are young but no good for an oldie like me! Competition helps a lot! This gives an adrenaline buzz which allows you top perform at a much higher level and increase fitness further.
- Do the "Body by Science" exercises once a week to increase your numbers of mitochondria and improve cardiovascular fitness.
- Do very gentle daily mobilisation exercise to put every joint and muscle through its full range of movement to stay supple.
- Anything else should be done, whenever you like, for pure fun in such a way that you do not risk injury nor exhaust the system!
If you "pay for it" the next day then you have overdone things - this is intentional in the "Body by Science" exercises but there must be a week for recovery before these exercises are repeated. Don't let the exercises for fun do this or they won't be fun any more!
If you wish to see another angle on the same theme go to Dr Mercola's website Mercola.com and read this page The Major Exercise Mistake I Made for Over 30 Years...