Undanfarin ár hefur íþróttafræðingurinn Kevin Tipton, einn helsti sérfræðingur heims í áhrifum prótein-neyslu heimsótt meistaranámið í íþróttafræði HR. Kevin stýrir teymi sérfræðinga við háskólann í Stirling og vinnur þar að rannsóknum meðal annars á áhrifum próteininntöku á líkamann.

Ég fékk að leggja fyrir hann nokkrar spurningar og það er mín von að svörin sem hann veitir geti nýst sem flestum. Spurningarnar og svörin eru á ensku og ég vona að það komi ekki að sök.

What are the most important steps for an athlete to take when dealing with long term injuries?

The most important steps may be the most obvious, but often given the least attention because they aren’t flashy.

1st) avoid nutrient deficiency. That goes for all nutrients, i.e. vitamins, minerals, macronutrients, and energy.

2) energy balance is important. There seem to be detrimental effects on healing and health if energy intake is too low following an injury. The first instinct will be to reduce energy intake since training/physical activity likely is reduced. However, reducing energy intake too much can decrease muscle protein synthesis and wound healing, thus impairing recovery. Energy excess also impairs recovery. So, attention to balancing energy intake with expenditure is important.

3) a relative increase in protein intake seems to be a good idea. I’d probably aim for 2-2.5 g protein/d/kg BW.

4) maintain physical activity as much as possible given the limitations of the injury. That is important in terms of general health, but also seems to positively influence healing and recovery.

Low carbohydrate diet during preseason (for a team sports athlete) – is it a good idea?

I suppose it depends on what you mean by low CHO (kolvetni) and what the training demands are for the athlete. As long as the athlete meets the CHO intake necessary to support training, then it should be fine. However, that goes for any time. James Morton has written some good stuff along these lines, so I recommend your readers go to his material.

Can LCHF diet make improvements to high-performance athletes?

I don’t know that LCHF diets do anything magic. Yes, you can see some metabolic adaptations that arguably may be positive. However, to date, there’s no convincing evidence of improved performance outcomes. In fact, Louise Burke and co have recently published a nice study (2nd one on the way) showing performance decrements. The issue for most athletes is that to perform best, it will be necessary to do increase power to do high-intensity periods of some sort in the competition. LCHF diets down regulate the enzymes crucial for using CHO for energy during high-intensity efforts. Trent Stellingwerf and colleagues nicely demonstrated this about 10 or more yrs ago. So, if you need to sprint in a match or surge up a hill in a race, your ability to generate power may be hampered.

There is an argument to limit CHO as a weight loss tool. However, at the end of the day, it is energy balance that is most important. Manipulating protein is probably better for weight loss, particularly if maintaining muscle mass during weight loss is important (see our paper from a few years ago – Mettler et al. Med Sci Sports Ex 2010).

What is the single best advice for athletes wanting fast post exercise recovery you have?

That’s a tough one. It depends on the sport and the athlete, of course. However, I suppose the 3 Rs – rehydrate, refuel and rebuild – are a place to start. But, I’m sure your readers know those.

Is casein protein a good supplement for intake before going to bed for muscle recovery?

For many, it doesn’t seem to hurt anything, at the very least. Although, some individuals report trouble sleeping and gut discomfort, particularly if large amounts are consumed. And, it seems that it is necessary for a larger amount of protein to be consumed to be effective.  I’m still dubious of the importance of pre sleep protein. no study has yet compared pre sleep protein to protein ingested at other times of day in terms of muscle protein synthesis [MPS] or muscle mass. All studies so far have given protein at night but didn’t include a comparison to the same amount of protein eaten earlier in the day. So, all the positive impact may simply be due to more protein. Luc and his crew will admit this when asked. Also, we published a study over 10 years ago in which overnight MPS was increased by resistance exercise with essential amino acid ingestion at mid day. We didn’t compare it to pre sleep protein, but those results at least suggest that it is possible to increase overnight MPS with exercise and protein earlier in the day.

The argument that casein is the magic protein specifically for pre sleep ingestion boggles my mind. Luc and gang used casein in those studies because they had a great deal of intrinsically-labeled casein, but no whey. No one has ever compared different proteins for pre sleep consumption. So, if someone wants to slug down a bunch of protein before bed, maybe worth a try. However, I’m unconvinced it is magic.

Is there a difference between nutritional recovery strategies wanting …

1. a) to maximize recovery, as in super-compensation phase
2. b) to recover as fast as possible

There is an argument to be made that those two considerations may be conflicting to some extent. Again, it probably depends on the athlete and the demands of the sport. So, it is a difficult question to answer without more info.

Ég þakka Kevin kærlega fyrir að hafa gefið sér tíma til að svara spurningunum og vona að svörin verði ykkur að gagni. Að þessu tilefni vil ég benda fólki á að Kevin heldur úti góðri twitter síðu þar sem hann deilir mörgum góðum rannsóknum og ráðum varðandi næringu, rannsóknir og íþróttir. Kevin Tipton á twitter.

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