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Get post-long run refuelling right

fridge foodIf your mom told you breakfast was the most important meal of the day, she was probably not a runner. Though important, breakfast comes up short when compared to the vital recovery meal after a long run.

Consider your post-race routine. Some runners immediately hit the showers. Others stretch or socialize. Some just lie on the ground. But it’s those runners sipping sweet drinks and chatting at the snack table who are efficiently and effectively building essential glycogen for their next run. The longer the race distance, the more critical it is to quickly refuel, no matter how tired you are.

Glycogen synthase, the enzyme responsible for glycogen production, is most active following an intense run, with the obvious goal of refilling the stores you’ve used. Muscle glycogen synthesis occurs in two phases. In the 30 minutes after a glycogen-depleting endurance session, muscle and liver cells are primed for refilling and muscle glycogen is rapidly made without insulin, the usual prerequisite hormone. Low glycogen levels signal carrier proteins to assemble on the cell wall, literally opening it to glucose passing in the bloodstream. After 30 minutes, production slows by about half for the next period, lasting up to five hours, and then returns to pre-race pace.

When you eat carbs after a long race, a big portion of that energy enters the bloodstream and is immediately swallowed by tissues other than the exercising muscles. The liver takes precedence, since this is where your body usually finds glucose to keep blood levels stable. This limits available glucose to maximize muscle glycogen. Your intestines only absorb about one gram of glucose per minute.

The best time to refuel those carbs is within minutes of crossing the line. Research consistently shows the highest muscle glycogen production rates happen with 1.2-1.8 grams of carb per kg body weight – 72-108 grams per hour for a 60 kg (130-pound)  runner-and when consumed immediately post-exercise. Repeat at 30-60 minute intervals for two-to-five hours afterward.

Though muscle glycogen stores fill twice as fast when carbohydrate is eaten right after exercise as opposed to waiting several hours, the thought of eating before your endorphin buzz wears off might make you queasy. To ease into eating, spread your carb intake over half-hour intervals for several hours, starting with liquid for the first two intakes. Using the same 60 kg runner, she could have 35 grams (1 cup of fruit juice) shortly after crossing the line and another cup half an hour later. This not only taps into the rapid regenesis phase, but also starts rehydration.

You can boost glycogen production further by adding protein, and even a couple specific amino acids. A combination of carbohydrate and protein starts amino acid transport for muscle tissue repair a little faster than usual protein synthesis rates. Certain amino acids like phenylalanine and leucine are also particularly good insulin stimulators, which further pushes glycogen synthesis. Aim for 0.2 to 0.4 grams protein per kg of body weight. The 60 kg runner needs 12-24 grams per hour. If she drank one cup of chocolate milk-with 30 g of carbs and 8 g of protein and a decent source of phenylalanine and leucine within 30 minutes and again later in the hour, she’d be well on her way to full power glycogen stores without stomach strain. But if protein is too much to tolerate, carb intakes over 1.2 g/kg provide the same glycogen production rates as a carb and protein combination-albeit without enhanced muscle repair effects.

Strength and energy aren’t the only things taxed on a long run. A bout of heavy exertion leads to temporary but clinically significant changes in immunity and defence against nasty bugs. Natural killer cell activity, T and B lymphocyte cell function, upper airway neutrophil function and other measures of defence all drop for at least several hours during post-marathon recovery. Stress hormone stimulation, dehydration, oxidative stress and muscle damage are all responsible for impaired immune action-cortisol, epinephrine, and pro- and anti-inflammatory cytokine increase markedly after extensive exertion. This window of impaired immunity lasts between three hours and three days, allowing viruses and bacteria ample time to invade. Larger increases in cytokines also mean more muscle damage.

Plasma cytokines like interleukins 6, 8 and 10, and tumour necrosis factor alpha (TNF-α) are known markers of immune stress. One study found that after the 100-mile (160K) Western States Endurance Run, IL-6 and IL10 concentrations increased by 130 and 30 times, respectively. Upper respiratory tract infections are also a common post-long run phenomenon, and those who log more than 90K per week double their odds for a URTI within two months of the race, according to another study.

Stress hormones have an intimate link with immune function, and most studies support that one litre per hour of a six-per-cent carbohydrate beverage during prolonged exercise eases stress hormone and inflammatory cytokine increases. The almighty carb molecule probably does this by squelching stress hormones like cortisol with insulin. Adequate energy also means interleukin and pro-inflammatory signal release from muscle tissue slows. Carbs however, are only a partial countermeasure to immune dysfunction.

 Phytochemicals, specifically anthocyanins like those found in red wine and cherry juice, can lower inflammation and oxidative stress to aid muscle recovery. The polyphenol curcumin, which gives turmeric its yellow colour, is also a powerful antioxidant. Quercetin, a flavonoid from the polyphenol family found in onions, apples, blueberries, curly kale, hot peppers, tea, and broccoli, also has antioxidative and anti-inflammatory activity. Instead of just juice, consider a glass of red wine with curried kale and chicken on your rice. It will surely get you a few steps closer to complete immune, muscle and glycogen recovery.

Sample Mini Meals for a 130-150 lb. runner:

1 large banana (50 g carb)

250 mL 1% chocolate milk (30 g carb, 8 g protein)

2 tbsp peanut butter (7 g carb, 8 g protein)

TOTAL: 87 g carb, 16 g protein

OR

700 mL Meal replacement drink (114 g carb, 28 g protein)

OR

Recovery smoothie

1 cup plain soy or dairy yogurt (18 g carb, 11 g protein)

1 cup blueberries (21 g carb)

1 cup apple juice (30 g carb)

1 scoop hemp protein powder (17 g carb, 10 g protein)

1 tbsp brown rice syrup (15 g carb)

Ice

TOTAL: 101 g carb, 21 g protein

Bobbi Barbarich is a contributing editor at Canadian Running.

 This article appeared in a previous issue of Canadian Running.

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