Effect of Protein Quality During Overreaching in Trained Cyclists

Monitoring Exercise Performance and Mitigating Training Stress in Endurance-trained Cyclists

Athletes frequently undertake periods of intensified training commonly referred to as "overreaching." These training periods acutely decrease performance, with the expectation that performance will rebound and improve after a short recovery. Yet, overreaching does not always improve performance and may be a precursor to overtraining syndrome, a long-term decrement in performance. A nutritional intervention focused on the adoption of 'best practices' for protein feeding (optimal timing, dose, and quality) could help reduce the stress of overreaching, reduce the likelihood of developing overtraining syndrome, and augment adaptations to intensified exercise. While the nutrition study is our main interest, the investigators first want to validate the measurement of exercise performance. Accordingly, this project consists of two related studies: (1) the assessment of short time trials for reliability and validity; and (2) the assessment of optimal protein feeding to decrease the stress of overreaching and improve outcomes following training.

Study Overview

• Status: Completed
• Conditions: Muscle Protein Synthesis
• Intervention / Treatment: Dietary supplement: Alpha-lactalbumin; Dietary supplement: Collagen peptides

Detailed Description

Endurance-trained athletes frequently undergo periods of overreaching (increased training loads) to improve performance. In study 1, the investigators will determine whether 4-min and 20-min time trials are repeatable and whether they (individually or collectively) relate to 1-hour time trial performance. For Study 2, the investigators propose that proper nutrition (with a focus on the dose, timing, and quality of protein) can help mitigate the stress of overreaching, which will improve performance. Thus, the investigators will compare the effects of two diets that differ in terms of protein servings (dose, timing, quality). In Study 2, skeletal muscle biopsies will be collected to determine how dietary protein intervention impacts the quality and quantity of skeletal muscle mitochondria in response to intense training.

For study 1, the objective is to determine the reliability and validity of 4-min and 20-min time trial performance (mean power output).

For study 2, the objective is to (1) determine whether following an optimal protein diet during a period of intense training will, relative to a typical diet: (1) improve measures of exercise performance, (2) improve sleep quality, psychological wellbeing, and immune function, (3) improve the quality and quantity of skeletal muscle mitochondria.

Study 1 is a reliability and validity experiment designed to assess the key outcome measure in study 2.

Study 2 is a randomized, crossover study. Participants will, in a randomized order, complete both conditions, separated by a 4-day washout period.

• Study Type: Interventional
• Enrollment (Actual): 11
• Phase: Not Applicable

Contacts and Locations

Study Locations

• Canada
  • Ontario
    • Hamilton, Ontario, Canada, L8S 4L8
      • Ivor Wynne Centre

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 18 years to 40 years (Adult)
• Accepts Healthy Volunteers: Yes
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• non-smokers
• non-diabetic
• Participants had to be training regularly (performing aerobic exercise at least 4 times per week, including regular cycling exercise)
• Generally healthy

Exclusion Criteria:

• consuming excessive alcohol (>21 units per week)
• use of an investigational drug or nutraceutical in the previous 30 days
• dairy allergy
• history of significant loss or gain of body mass in the past 6 months (>2kg)
• regular use of non-steroidal anti-inflammatory drugs
• infectious disease, and/or the presence of any relevant disease (e.g., gastrointestinal, cardiovascular, neuromuscular, etc.).

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Other
• Allocation: Randomized
• Interventional Model: Crossover Assignment
• Masking: Triple

Number of Arms

2

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: Alpha-lactalbumin; Participants will consume 60 g of alphalactalbumin (fraction of whey protein) for 3 training days.	Dietary supplement: Alpha-lactalbumin; A protein fraction of whey protein, higher in tryptophan
Active Comparator: Collagen peptides; Participants will consume 60 g of collagen peptides for 3 training days.	Dietary supplement: Collagen peptides; Collagen peptides from bovine sources

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Rate of myofibrillar muscle protein synthesis	Rate of myofibrillar and protein synthesis (%/day)	12 days
Rate of Sarcoplasmic muscle protein synthesis	Rate of sarcoplasmic muscle protein synthesis (%/day)	12 days

Secondary Outcome Measures

Outcome Measure	Measure Description	Time Frame
Plasma amino acids	Measurement of plasma amino acids 1 hour following ingestion of each beverage	1 x 1 hour
Sleep efficiency (%)	Measured by Actigraphy	12 days
Sleep fragmentation	Measured by Actigraphy	12 days
Wake after sleep onset (WASO) in minutes	Measured by Actigraphy	12 days
Total sleep time (min)	Measured by Actigraphy	12 days

Collaborators and Investigators

• Sponsor: McMaster University
• Investigators: Principal Investigator: Stuart Phillips, PhD, McMaster University

Study record dates

Study Major Dates

• Study Start (Actual): November 1, 2017
• Primary Completion (Actual): April 1, 2018
• Study Completion (Actual): August 30, 2018

Study Registration Dates

• First Submitted: June 19, 2019
• First Submitted That Met QC Criteria: June 20, 2019
• First Posted (Actual): June 21, 2019

Study Record Updates

• Last Update Posted (Actual): June 21, 2019
• Last Update Submitted That Met QC Criteria: June 20, 2019
• Last Verified: June 1, 2019

More Information

Terms related to this study

• Other Study ID Numbers: HIREB 3036

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: NO

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No