Depending on several factors nutritional needs will differ in response to our training goals.
In this deep dive I will be addressing nutritional needs in relation to those looking to optimise strength and hypertrophy.
After an intense resistance workout our bodies are often depleted of glycogen and amino acids as well as physical damage to the muscle fibres worked.
We often refer to the immediate time after we have trained as “the window of opportunity” Theoretically by consuming the appropriate ratio of nutrients at this time helps facilitate restoration of energy reserves as well as repair damaged tissue in a super-compensatory fashion.
However, recent research suggests that this theoretical “window of opportunity” may be dependent on a number of factors.
Furthermore, high-intensity resistance training with moderate-low volume (bodybuilders and strength athletes) has only been shown to reduce glycogen stores by 36-39%
An argument could be made that in strength athletes and bodybuilders the need for post workout (PWO) carbohydrate consumption is less important that for those performing multiple times per day or those who have trained in a fasted state.
However, in skeletal muscle glycogen is localised and although only constituting 4-15% of the total glycogen content, the availability of intramyofibrillar glycogen has been shown to be of particular importance to muscle function and restoration.
Additionally, exercise enhances insulin-stimulated glucose uptake following a workout with a strong correlation noted between the amount of uptake and the magnitude of glycogen utilization.
A purported benefit of post-workout nutrient timing is an attenuation of muscle protein breakdown (MPB) This is primarily achieved by spiking insulin levels, as opposed to increasing amino acid availability.
Another factor to consider is how pre nutrition affects performance output. Glycogen is considered essential to optimal resistance training performance, with as much as 80% of ATP production during such training derived from glycolysis. Moreover, glycogen serves to mediate intracellular signalling.
For post workout (PWO) a 4-1 ratio of carbs to protein is advocated to optimise muscle protein synthesis (MPS) whey protein isolate and dextrose are a good choice here as they’re fast acting and easy to digest.
As mentioned dextrose is fast digesting, readily absorbed isomer. It helps to raise blood sugar levels quickly, causing a fast spike in nutrient-transporting insulin into the bloodstream. Essentially it speeds up nutrient absorption to the muscles PWO.
In terms of protein dosing a high-quality protein dosed at 0.4–0.5 g/kg of lean body mass (LBM) at both pre- and post-exercise is a simple, relatively fail-safe general guideline that reflects the current evidence showing a maximal acute anabolic effect of 20–40 g. Exceeding this would have minimal detriment (other than for those on a calorie controlled diet), whereas significantly under-shooting or neglecting it altogether would not maximize the anabolic response.
Carbohydrate ingestion at a rate of ≥1.2 g carbohydrate per kg body mass per hour appears to maximise post-exercise muscle glycogen repletion rates.
Additionally we can maximise the glycogen effect by combining glucose and fructose to provides faster rates of carbohydrate absorption that dextrose rates alone.
Depending on our lifestyle factors we may be able to optimise our meal timings in relation to our workouts. For example, if a significant delay in the post-exercise meal is anticipated we can ensure a pre workout meal is consumed to ensure glycogen levels remain high and mitigate MPB.
A typical mixed meal will take approximately 1–2 hours for circulating substrate levels to peak, and 3–6 hours (or more) for a complete return to basal levels depending on the size of a meal. Taking this into consideration it could be argued that as long as a decent meal of proteins, carbohydrates and fats are consumed a few hours prior to our workout we may have leeway on that perceived “window of opportunity”
If for example you are performing a 60-minute resistance training, you could have up to 90-minute feeding windows on both sides of the bout, given central placement between the meals.
If you are someone who must train upon waking and cannot perform optimally on a full stomach a good port of call would be to consume a larger meal the night before containing proteins, carbs and fats. Whilst you train you may experience a boost in performance by drinking a fast digesting carbohydrate + BCAA shake throughout your workout.
Alternatively, for intra-workout you could consume some form of easily digesting carb. Liquorice is especially good as it is loaded with dextrose, ultimately to prevent insulin levels from dropping and going into a catabolic state.
The ultimate takeaway is that although a post workout feed containing carbs and protein is important for MPS we still have dietary flexibility whilst in pursuit of optimal timing.
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Mankel Over Matter - Getting Stronger Together.
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