Collagen Vitamin C Dose Response Performance

In preliminary work investigating the physiological determinants of maximal performance in throwing events, researchers found that the best predictor of elite performance was the rate of force development (RFD; Force (N) x time (sec)) when performing and isometric squat. Therefore, it is not surprising that in order to maximize performance, athletes train to optimize RFD.

RFD is determined by three factors:

1. Neural activation of the muscles
2. Type of motor protein (fast or slow myosin)
3. Force transfer Interestingly, performance in power movements (that are highly dependent on RFD) like vertical jump is closely related to tendon stiffness and inversely related to muscle size. This indicates that force transfer, in the form of tendon stiffness, plays an important role in performance and can explain a large amount of variance in determining an athlete's ability to rapidly develop force during a dynamic movement.

The stiffness of a tendon is determined by the amount and cross-linking of collagen within the tissue. Acute exercise is known to increase collagen synthesis as well as the expression of the primary enzyme involved in collagen cross-linking, lysyl oxidase. The result is a denser and stiffer tissue after training. Even though the relationship between exercise and collagen synthesis is known, whether this measure of performance can be improved with nutritional interventions has not been determined.

A recent study looking at amino acid levels following consumption of increasing doses of gelatin (derivative of collagen) in human subjects has shown that the key primary and trace amino acids found in collagen increase in human serum after consuming gelatin. Further, the peak of these amino acids occurs 60 minutes after consuming the gelatin supplement. Therefore, consuming a collagen supplement 1 hour before an exercise intervention should maximize delivery of amino acids to bone and other connective tissues.

To determine whether the gelatin supplement could increase collagen synthesis in humans, subjects consumed placebo, 5 or 15 g of gelatin with a standard amount of vitamin C (48 mg) 1 hour before 6 minutes of jump rope exercise. The feeding and exercise intervention was repeated every 6 hours while the subjects were awake for three days and the amount of the amino terminal procollagen I peptide (PINP) was determined; a marker of collagen synthesis, in the blood. Consistent with the hypothesis that gelatin increases collagen synthesis in humans; the amount of PINP in the 15 g gelatin group was significantly higher than either the placebo or the 5 g groups. These data conclusively demonstrate that gelatin supplementation can increase exercise-induced collagen synthesis in humans.

Similarly, supplementation with collagen hydrolysate has previously been shown to improve cartilage function in a randomized clinical trial in patients with osteoarthritis [9]. McAlindon and colleagues showed that consuming 10 g of collagen hydrolysate per day resulted in an increase in gadolinium enhanced MRI of collagen [9]. This finding suggests that the hydrolyzed collagen increased cartilage formation. In agreement with this finding, a 24-week randomized clinical trial in athletes showed that 10 g of GELITA® collagen hydrolysate significantly decreased knee pain. Mouse studies using C14 labeled hydrolyzed collagen hydrolysate demonstrated that >95% of the hydrolyzed collagen was absorbed in the first 12 hours after feeding. Interestingly, even though tracer from a separate C14 labeled proline could be incorporated into skin collagen at the same rate as tracer from hydrolyzed collagen, tracer from the hydrolyzed collagen was incorporated into the collagen of cartilage and muscle two-fold more than the tracer from proline. These data suggest that musculoskeletal collagen synthesis is greater in response to gelatin or hydrolyzed collagen than to the individual amino acids.

Even though the blood measure of PINP levels likely reflects bone collagen synthesis, using an engineered ligament model, a similar response has been demonstrated in tendons/ligaments treated with serum from people 1 hour after supplementation with gelatin. This work has shown that in the presence of serum isolated from the 5 and 15 grams of gelatin groups a step-wise increase in the collagen content of the ligaments. From this work, it can be ascertained that PINP can be used dependably as an indirect marker of collagen synthesis and that the changes observed in bone (blood levels) reflect what is occurring in other connective tissues as well.

The current study aims to precisely map out the dose response relationship of hydrolyzed collagen and vitamin C on PINP and to determine the optimal dose to achieve maximal increased in PINP levels. Secondly, whether this optimal dose of hydrolyzed collagen and vitamin C, taken before training is sufficient to improve RFD and performance will be determined. To achieve this goal, subjects will first consume increasing doses of hydrolyzed collagen (0 (control), 5, 10, 20 and 30 g) alongside a constant amount of vitamin C (50 mg). Once the optimal dose of hydrolyzed collagen is determined this dose will be administered with increasing doses of vitamin C (0 (control), 50, 250, 500 mg) to determine the optimal dose of vitamin C to maximize PINP levels. Both hydrolyzed collagen and vitamin C supplementation will be given 1 hour before 6 minutes of jump rope exercise.

After the optimal doses of hydrolyzed collagen and vitamin C are determined, the effects of the optimal dose of hydrolyzed collagen and vitamin C on performance will be assessed. Subjects will undergo an explosive/power-based exercise training program three days a week (Monday/Wednesday/Friday) for three weeks. The hydrolyzed collagen and vitamin C will be ingested 1 hour before each training session. Baseline exercise testing will take place at week 0, then exercise testing will occur on Friday of each week (week 1, 2 and 3). Subjects will undergo a series of tests to determine the RFD in the isometric squat, and countermovement and squat jump height.