LECTURE 21-1 November 2010
Physical activity
Aerobic
-diet and aerobic exercise
Anaerobic
-diet and anaerobic exercise
Interval training
-diet and interval training exercise
Aerobic
If one has been maintaining their (healthy) weight by combination of diet and exercise-great
and if one wishes to continue to maintain weight while eating more calories across all of Canada’s food groups, one must exercise to the point that weight is maintained
Calories in = calories out
If trying to lose unhealthy weight, exercise and as well one should:
a) reduce calories across all of Canada’s food groups or
b) maintain caloric intake eating across all 4 of Canada’s food groups and exercise harder than option a-which option is better? And why?
Calories out (calories expended due to exercise) must be greater that calories in (caloric intake in the form of food)
is there any other type of caloric intake other than food?
Lipid
No benefit to increasing lipid intake because there are almost limitless stores of free fatty acids in the well fed individual
As such there are no grounds for assuming that an increase in the lipid stores will increase performance even during prolonged exercise
Thus the limitation to work at low workloads appear to be related to other factors than the lack of substrate
Should be about 25 % of caloric intake
Carbohydrate
As the intensity (measured as percentage VO2 max) and duration of aerobic exercise increases there is increased demand for carbohydrate utilisation and less demand for lipid
Consequently as the intensity of the exercise is increased one must consume more carbohydrate- this is the concept of carbohydrate loading
The onset of hypoglycaemia can limit prolonged exercise if the liver glycogen store at the start of exercise is low and no carbohydrate is taken in during the exercise
Eat more pasta between exercise sessions
Should be about 55-60 % of caloric intake
Protein
In contrast to fat and carbohydrates there is no existing evidence that any specific body protein store can be increased by diet
Proteins can be used for energy but as one increases the glycogen stores in muscle there is a protein sparing effect
Any increase in protein requirements to make up for protein utilisation can be made up by increasing total calorie intake across Canada’s four food groups
Should be about 15 % of dietary caloric intake
Minerals
are lost due to sweating-must be made up in dietary intake-if excessive there is the possibility of heart failure
consume during exercise with water
dietary iron must be sufficient to carry oxygen
Vitamins-eat according to Canada’s food guide and vitamins will be sufficient to meet needs- this is controversial
Water
is lost due to sweating-must be made up in dietary intake
necessary for the transport of nutrients, maintenance of mineral balance, elimination of metabolites and maintenance of blood pressure and body temperature
avoid excessive water intake- dilutes minerals with possibility of heart failure
Anaerobic
Carbohydrate protein and lipid intake should be the same as above for aerobic exercise in terms percentage of caloric intake-
Reminder during supramaximal exercise there is the use of phosphocreatine to supply ADP with a phosphate to increase the ATP available. ATP hydrolysis results in the yielding of energy to allow muscles to contract
Increase in dietary creatine increases creatine phosphate in the body and increases performance in anaerobic physical activity- such increased creatine has no role in submaximal exercise
Creatine in food
No intake in vegetarians and up to 2 grams creatine intake a day if one is eating meat and fish in accordance with Canada’s food guide
Minerals
are lost due to sweating- must be made up in dietary intake- if excessive there is the possibility of heart failure
consume during exercise with water
dietary iron must be sufficient to carry oxygen
Vitamins-eat according to Canada’s food guide and vitamins will be sufficient to meet needs- this is controversial
Water
is lost due to sweating- must be made up in dietary intake
consume during exercise
necessary for the transport of nutrients, maintenance of mineral balance, elimination of metabolites and maintenance of blood pressure and body temperature
Interval training
Carbohydrate, protein and lipid intake should be the same as above for aerobic exercise in terms percentage of caloric intake
Intermediate between aerobic and anaerobic activity but leaning more toward the aerobic if for example interval training favours the aerobic side of activity
Minerals
are lost due to sweating- must be made up in dietary intake
consume during exercise with water
dietary iron must be sufficient to carry oxygen
Vitamins
-eat according to Canada’s food guide and vitamins will be sufficient to meet needs- this is controversial
Water
is lost due to sweating- must be made up in dietary intake- if excessive there is the possibility of heart failure
consume during exercise
necessary for the transport of nutrients, maintenance of mineral balance, elimination of metabolites and maintenance of blood pressure and body temperature