Developing your own nutrition program

To review, the most important of these concepts include:

• a high carbohydrate training diet is a must to maximize your internal (liver and muscle) glycogen stores.
• there may be a slight increase in daily protein requirements, with training, but replacement needs can be met with 1 gram protein/kg body wt/day.
• When training regularly, or riding multiday, endurance events, Caloric expenditures need to be consciously replaced to counteract the appetite suppression that follows from long hours of training.
• a 3 day, pre event, carbohydrate loading program gives you an edge in maximizing muscle/liver glycogen storage.
• A good breakfast the day of the event.
• a 4 hour pre event meal should be utilized to top off glycogen stores.
• some riders experience intestinal distress or symptoms of hypoglycemia if they eat in the 2 to 4 hours immediately before an event.
• Calories must be taken during an event of greater than 2 hours duration to avoid depleting your internal energy (glycogen) stores. Solid foods may offer some advantages in longer events, ridden at slower paces, but in high exertion (> 70 - 80 % VO2max) liquid supplements minimize problems from delayed gastric emptying.
• be particularly sensitive to your overall fluid balance (loss vs replacement) as the risks of OVERHYDRATION as well as DEHYDRATION increase with longer events. The best strategy is to weigh yourself regularly during training as well as after/during longer events.
• salt replacement beyond that in a normal diet (ie commercially available sports drinks) is necessary only under extreme conditions or in events lasting 8 to 10 hours or more .

Having a plan and then sticking to that plan is the formula to ride at your best. It has been shown that if you wait until you feel you need to drink or eat, you are already behind the curve - and then will never catch up. So you should aim for at least 1000 ml of fluid per hour and, if you are riding more than 2 hours, 90 grams of carbohydrate supplementation as well. You can read more on replacement at Sports Drinks.

First, let's review a few tips that can be of benefit in a nutritional training program.

• Eat a good breakfast each day - and work to balance your Caloric intake throughout the day. This tantalizing article from Medscape.com suggests that even an afternoon ride is compromised by skipping breakfast even after eating a slightly greater than normal lunch to compensate.
• Practice eating while cycling - your stomach needs to get used to handling food while exercising. You cannot "train" your digestive system to get bigger or stronger, but you can define your own limitations and personal digestive quirks before the day of the big ride.
• Don't switch foods on ride day - stay with the on the bike foods you are use to eating.
• Make it simple for your digestive system - use processed breads rather than whole grains, liquids rather than solids, cooked vegetables instead of raw ones, and minimize fat.
• Don't fill up before the finish - anything you eat in the last 30 minutes will probably still be in your stomach, and if you sprint at the end, it increases the incidence of nausea and vomiting.
• Train more - the best way to improve digestive system functioning is to get in better shape improving your cardiovascular training. As you raise your peak level of performance, you widen the range of exertion within which your stomach functions normally.

• determine your daily Caloric needs as outlined in the section on energy requirements of cycling.
• calculate your body weight (BW) in kg (Wt in lbs x .455 = BW in kg)
• eat a baseline daily diet of:
  • protein - 1.5 gm x BW in kg (multiply x 4 to get daily protein Calories)
  • fat - 70 gm fat (the avg. American diet); at 9 Cal/gm = 630 Calories
  • carbohydrates - the balance of your total daily Calories (total requirements as calculated above minus protein Calories minus fat Calories)as starches, etc.
• modify that diet for the specific periods noted below
  • Pre-event interval (4 days to the event)
  • During the event
  • Post event

Your pre event nutrition will be a key factor in avoiding RED-S or the Relative Energy Deficiency in Sport. To do so will mean estimating your Caloric needs for a competitive event (or day's training) and then actively replacing them to avoid the fatigue associated with chronic glycogen depletion.

Although a good breakfast will keep you headed in the right direction, a well planned pre ride nutrition program is key to avoiding RED-S.

You can estimate how many Calories you will need. For the first 90 minutes, they all are supplied from internal muscle and liver glycogen stores. But for longer rides you will need additional supplemental carbohydrate Calories from snacks on the bike (or on their way toward the muscles from a pre ride meal working its way through the digestive tract), or risk bonking.

Let's review the physiology behind choosing what to eat and the four most significant factors that impact an athlete's digestion.

1. Solid versus liquid - liquids are emptied from the stomach more quickly than solids.
2. Fat content of the food - fat slows the digestive process and delays the availability of any Calories in the food to the muscles.
3. Sugar concentration - especially in liquids, a sugar content of more than 10% will slow stomach emptying. (The use of complex carbohydrates, due to the decreased osmotic effect, will offset this to some degree and offers an alternative strategy to maximize Caloric intake to offset the metabolic needs of exercise.)
4. Physical activity level of the cyclist - the mechanical activity of digestion is slowed by any vigorous activity, usually starting at 70% VO2 max. Except in short, all out events, this is rarely an issue, and it is much less so for cycling than for running where the additional component of mechanical stimulation of abdominal contents from the sport itself slows digestive tract functioning.

4 days prior to the event

• 9 gm carbohydrate/kg BW/day (approx. 600 grams/day)
• limit exercise to minimum needed to maintain flexibility

Assuming maximized glycogen stores, nutrition in the 4 hour pre-race interval could give you an edge. A meal high in carbohydrates to top off glycogen stores is essential for all riders. It is the amount of fat in the meal that could change your results.

Free fatty acids (FFA), absorbed from the fat, inhibit glycogen breakdown and thus availability of glucose to supply ATP for muscle cell energy. Energy metabolism shifts from more efficient glucose pathways towards less efficient fat energy production. Being less efficient (fewer ATP produced per molecule of oxygen available than from glucose) total ATP production falls off and the level of maximal exertion possible with pure glucose metabolism alone decreases.

For moderate exertion rides (60 - 80 % VO2max), some fat in the pre-ride meal is not a problem and actually might be of benefit IF carbohydrate (glucose) gels or drinks are started just as you get on the bike. In this scenario the FFAs spare internal glycogen stores which may allow longer multi hour rides before the inevitable exhaustion from depleted glycogen occurs.

But for optimal performance at higher % V02max, a time trial for example, the inhibition of glucose release from glycogen would theoretically limit the number of glucose calories available per minute to power the muscle cells and thus maximal performance.

A carbohydrate loading protocol, followed by a relatively high-fat meal 4 hours prior to exercise and beginning your gel /energy drink supplement program just as you get on the bike is the ideal approach for the majority of riders.

• eat a 300 gm complex carbohydrate meal (rice, starch, pancakes, etc.)
• a high Caloric density glucose polymer sports drink may be ideal here
• define your own physiologic limits if you are accustomed to eating in the 4 hours interval before a ride - many riders get a psychological boost from eating a low fat meal or a liquid carbohydrate drink/gel during this interval (and as a bonus can supplement their internal glycogen stores for a ride of more than 1 to 2 hours)

4 minutes prior to the event

• 45 gm carbohydrate (candy bar for example)

• calories
  • regular carbohydrate replacement - start immediately
  • 60 gram of carbohydrate as a minimum per hour
  • liquid preferred (i.e. sports drink)
  • 10% concentration optimal (equivalent to a cola drink)
  • start with half a water bottle (300 ml) in your stomach
  • complex carbohydrate drinks permit additional Calories
• liquids
  • 800 ml/hour (a std water bottle = 590 ml)
  • drink at 10 - 15 min. intervals

• 3 to 6 gm carbohydrate/ kg BW over the immediate 4 hours post event (100 grams per hour) - start immediately
• a high Caloric density glucose polymer sports drink may be ideal here
• protein appears to expedite glycogen replacement
• 600 gm carb/day for 2 days to optimize repletion of muscle/liver glycogen.