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Introduction/Summary.
There is remarkably little scientific research available around exercise while on a ketogenic diet. This section is a brief review of the av..."
{{Skeleton}}
Introduction/Summary.
There is remarkably little scientific research available around exercise while on a ketogenic diet. This section is a brief review of the available studies.
* Phinney-1983. This study looked at the effect of four weeks on a [[Ketogenic Diet]] on 5 elite cyclists, and found that their endurance was maintained.
** The diet was 15% of calories from protein, 85% from fat, with less than 20g of carbohydrate.
** Subjects were performed VO2max and endurance tests before and after the [[Ketogenic Diet]].
** Unlike typical fat metabolism, the oxygen cost of calories was not different on the [[Ketogenic Diet]].
*** There are some similar observations from other non-exercise studies.
** The RQ on the VO2max test dropped from 1.04 to 0.9, and on the endurance test from 0.83 to 0.72, indicating a shift in substrate metabolism.
** The endurance test did not include any fuel, just water. It is likely that the endurance test would have had a better result in the control condition with carbohydrate supplementation.
** Blood glucose during the endurance test was similar after the [[Ketogenic Diet]] to before, but the rise and fall were somewhat reduced. At no point did blood glucose drop to the point of hypoglycemia. Blood glucose provided an estimated 28% of calories on the normal diet and 9% of calories on the [[Ketogenic Diet]].
** Blood levels of 3-hydroxybutyrate, which indicates ketogenisis, were insignificant on the normal diet and elevated on the [[Ketogenic Diet]].
** Muscle glycogen levels where higher before the endurance test on the normal diet than on the [[Ketogenic Diet]] (143 and 53 respectively). Both tests had similar muscle glycogen levels after the endurance tests. It is interesting to see that muscle glycogen levels were replenished somewhat on the [[Ketogenic Diet]], even though the subjects continued normal training for the four weeks.
** The five subjects had an endurance time of 147 minutes on the normal diet and 151 minutes on the [[Ketogenic Diet]]. However, the individual responses are rather different.
*** Two subjects dramatically increased their endurance time on the [[Ketogenic Diet]], one by 57% and another by 30%. The subject whose endurance improved by 57% had much lower final muscle glycogen levels on the [[Ketogenic Diet]] than the normal diet (41.5 compared with 59.2).
*** One subject had an almost identical endurance time.
*** Two subjects had a dramatic decrease in their endurance, one by 36% and another by 28%. The subject that decreased their performance by 36% had complained of overtraining and had reduced his training level the month before the trial.
**** The subject that reduced their performance by 28% has higher final glycogen levels after the ketogenic endurance test than the normal diet (38.1 compared with 58.4).
{{KetoSeeAlso}}
Introduction/Summary.
There is remarkably little scientific research available around exercise while on a ketogenic diet. This section is a brief review of the available studies.
* Phinney-1983. This study looked at the effect of four weeks on a [[Ketogenic Diet]] on 5 elite cyclists, and found that their endurance was maintained.
** The diet was 15% of calories from protein, 85% from fat, with less than 20g of carbohydrate.
** Subjects were performed VO2max and endurance tests before and after the [[Ketogenic Diet]].
** Unlike typical fat metabolism, the oxygen cost of calories was not different on the [[Ketogenic Diet]].
*** There are some similar observations from other non-exercise studies.
** The RQ on the VO2max test dropped from 1.04 to 0.9, and on the endurance test from 0.83 to 0.72, indicating a shift in substrate metabolism.
** The endurance test did not include any fuel, just water. It is likely that the endurance test would have had a better result in the control condition with carbohydrate supplementation.
** Blood glucose during the endurance test was similar after the [[Ketogenic Diet]] to before, but the rise and fall were somewhat reduced. At no point did blood glucose drop to the point of hypoglycemia. Blood glucose provided an estimated 28% of calories on the normal diet and 9% of calories on the [[Ketogenic Diet]].
** Blood levels of 3-hydroxybutyrate, which indicates ketogenisis, were insignificant on the normal diet and elevated on the [[Ketogenic Diet]].
** Muscle glycogen levels where higher before the endurance test on the normal diet than on the [[Ketogenic Diet]] (143 and 53 respectively). Both tests had similar muscle glycogen levels after the endurance tests. It is interesting to see that muscle glycogen levels were replenished somewhat on the [[Ketogenic Diet]], even though the subjects continued normal training for the four weeks.
** The five subjects had an endurance time of 147 minutes on the normal diet and 151 minutes on the [[Ketogenic Diet]]. However, the individual responses are rather different.
*** Two subjects dramatically increased their endurance time on the [[Ketogenic Diet]], one by 57% and another by 30%. The subject whose endurance improved by 57% had much lower final muscle glycogen levels on the [[Ketogenic Diet]] than the normal diet (41.5 compared with 59.2).
*** One subject had an almost identical endurance time.
*** Two subjects had a dramatic decrease in their endurance, one by 36% and another by 28%. The subject that decreased their performance by 36% had complained of overtraining and had reduced his training level the month before the trial.
**** The subject that reduced their performance by 28% has higher final glycogen levels after the ketogenic endurance test than the normal diet (38.1 compared with 58.4).
{{KetoSeeAlso}}
