Statistics Question-Chocolate & Cycling

Chocolate & Cycling

You have been hired by a bicycle team to help them train for the Tour de France. The head trainer recently read an article, which presents the results of a study about the effects of the consumption of chocolate (dark chocolate and white chocolate) on a number of important outcome variables during cycling. These outcome variables included: oxygen consumption (ml/kg/min), heart rate (bpm), blood lactate (BLa), blood pressure (mmHg), and an all-out bicycle sprint performance (meters).

The experimental setup consisted of a randomized design where the various outcome variables of n = 9 male participants was measured in two trials after participants consumed either 40 mg of dark chocolate or 40 mg of white chocolate, each for two weeks. Prior to receiving the first treatment, each participant underwent baseline measurements on the outcome variables.

The trainer was specifically interested in the results for the all-out sprint performance which measured the distance traveled (in meters) for a two-minute time trial. He would like to know how the regular consumption of chocolate affects the total distance covered during an all-out sprint and if the type of chocolate consumed matters.

Some of these results are presented in the table below.

Distance Covered (in meters = m) during Time Trial* Note: n = 9 for each condition

Dark Chocolate: 95% Confidence Interval for the population average change in total distance covered (dark chocolate over baseline) is 165 m to 314 m

Dark versus White Chocolate: 95% Confidence Interval for the population average change in total distance covered (dark chocolate over white chocolate) is 82 m to 292 m

The trainer knows you have some statistics background and wants your help on understanding and interpreting these results. Based on the results from the article, write a memorandum to the trainer addressing his questions and explaining what these statistics results show.

Although this sample size is small, you can consider it a reasonable one for this type of study, and can thus focus on interpreting the results. Include a basic description of hypothesis testing. Be sure to comment about the two provided confidence intervals, including an interpretation of both confidence intervals, and an explanation of the meaning of the confidence level in context. Finally, include in your memorandum your recommendation, with stats rationale, for or against inclusion of chocolate (and if inclusion, which type of chocolate) in the athletes’ diet.

Data is from: Patel, R. K.; Brouner, J.; Spendiff, O. Journal of the International Society of Sports Nutrition. 2015 12:47

A Few Notes for Completing the Assignment

Some Items to keep in mind:

• When your memorandum is read by the head trainer with minimal statistical literacy, who is trying to understand these results.
• Since you are explaining this to your client, the head trainer, you should take care to carefully edit and proofread your memorandum.
• Your memorandum should be between 350-500 words (excluding header, footer, citations). In case you aren’t sure what memorandum (or, “memo”) format should look like: https://owl.purdue.edu/owl/subject_specific_writing/professional_technical_writing/memos/parts_of_a_memo.html
• Sample memo found here https://owl.purdue.edu/owl/subject_specific_writing/professional_technical_writing/memos/sample_memo.html
• You will need to include citations and sources when discussing the data from this study. When referencing the data, you can use the following source: R. K.; Brouner, J.; Spendiff, O. Journal of the International Society of Sports Nutrition. 2015 12:47. If you use additional sources in your response, be sure to include in-text citations and a references section and use APA format.

Hypothesis testing should be described in this memo. Comment on how the submission addresses hypothesis testing design.

1. What is described well?
2. What is missing? How might the description be improved?

Comment on how the submission addresses the sample size and how it could affect the outcome of the hypothesis test.

1. What is explained well?
2. What is missing? How might the explanation be improved?

Comment on how the submission addresses what the p-values indicate about the results, and the meaning of statistical significance.

1. What is explained well?
2. What is missing? How might the explanation be improved?

Comment on how the submission provides an interpretation of both confidence intervals, and an explanation of the meaning of the confidence level in context.

1. What is interpreted well?
2. What is missing? How might the description be improved?

Comment on the recommendation provided for or against inclusion of chocolate (and if inclusion, which type of chocolate) in the athletes’ diet.

1. What is described well?
2. What is missing? How might the description be improved?

Hypothesis testing should be described in this memo. Comment on how the submission addresses hypothesis testing design.

3. What is described well?
4. What is missing? How might the description be improved?

Comment on how the submission addresses the sample size and how it could affect the outcome of the hypothesis test.

5. What is explained well?
6. What is missing? How might the explanation be improved?

Comment on how the submission addresses what the p-values indicate about the results, and the meaning of statistical significance.

1. What is explained well?
2. What is missing? How might the explanation be improved?

Comment on the recommendation provided for or against inclusion of chocolate (and if inclusion, which type of chocolate) in the athletes’ diet.

3. What is described well?
4. What is missing? How might the description be improved?

PEER REVIEW Guidance:

1. Use respectful language whether you are praising your peer or suggesting improvements.
2. Read over your peer’s memo to quickly get an overview of the piece.
3. Next, read the memo more slowly keeping the rubric in mind.
4. As you re-read, take note of the pieces of texts that let you directly address the rubric prompts.
5. Focus on larger issues (higher order concerns) of content and argument rather than lower order concerns like grammar and spelling.
6. Be very specific in your feedback, referring to your peer’s actual language, mentioning terms and concepts that are either present or missing, and following the directions in the rubric.
7. Peer Review is important and helpful (to both the reviewer and receiver of the review), so be sure your online responses are detailed enough (minimum word count for each of the 4 criteria is 30 words).
8. Peer Review can only be helpful if completed on time so that the feedback can be given back to your peers through this peer review tool. Complete your thoughtful online feedback of all your assigned submissions ON TIME so you can provide that feedback and thus earn your points for this helpful exercise.