RESEARCH: Studies from 5 to 11 Aug 24
Sharing research and insights from coaches, scientists and athletes to help us improve endurance performance.
This week’s quick summary:
The minimal dose of exercise needed to preserve endurance
Effect of different work-matched efforts on subsequent performance
Long-term development of performance and training characteristics
Carbohydrate does not augment exercise-induced protein accretion
Cycling time trial performance is impaired with multiple feedback
DETRAINING: Maintaining physical performance: The minimal dose of exercise needed to preserve endurance and strength over time
All athletes go through period of detraining either at the end of a season or due to illness or injury. In these cases, it is useful to understand the rate of detraining and what can be done to mitigate it. In this study, the authors set out “to determine the minimal dose of exercise (i.e., frequency, volume, and intensity) needed to maintain physical performance over time”.
STUDY DETAILS
The study includes general populations and notes differences for younger and older individuals.
Endurance training frequency can be reduced to 2 sessions per week, with volume cut by 33-66% (13-26 minutes per session), provided intensity remains high.
Endurance performance can be maintained for up to 15 weeks; strength and muscle size can be preserved for up to 32 weeks.
Key metrics include training frequency, volume (session duration), and intensity (heart rate and relative load).
Younger individuals can maintain muscle size with 1 strength session per week and 1 set per exercise, while older individuals require 2 sessions per week and 2-3 sets per exercise to maintain muscle size.
PRACTICAL TAKEAWAY
The results of this study show that to maintain endurance and strength during periods of limited exercise time the focus should be on preserving exercise intensity. While the participants in this study were not elite athletes, the general principle of the potential to maintain fitness with significantly reduced training is something to consider. My recommendation for athletes going through periods with reduced training is to remember that maintaining fitness takes far less training than building fitness. I wouldn’t recommend cutting training to as low as the examples in this study, but periods with 50-70% of normal training load don’t have to be times of lost fitness when some careful planning and use of intensity can ensure that fitness is maintained.
RELATED RESEARCH
LOAD: Intensity matters: Effect of different work-matched efforts on subsequent performance in cyclists
There are multiple different training load metrics (such as TSS, Relative Effort, TRIMP, etc) which have the intention of measuring the impacts of different sessions and comparing their impact on the athlete. These metrics assign different weights to the intensity performed in a session. In this study, the authors set out “to assess the effect of 2 work-matched efforts of different intensities on subsequent performance in well-trained cyclists”.
STUDY DETAILS
Twelve competitive junior cyclists, aged 17 years with a maximum oxygen uptake of 71.0mL/kg/min participated in the study.
Two training sessions were matched for mechanical work (~15kJ/kg) but differing in intensity: a moderate-intensity continuous-training session (60%–70% of critical power; CP) and a high-intensity interval session (3-minute bouts at 110%–120% of CP with 3-minute rest periods).
The study followed a randomized controlled crossover design with field tests conducted on subsequent days after the intervention.
Power-duration relationship was assessed through 2-minute, 5-minute, and 12-minute field tests under fresh conditions and after each training session.
There was significantly lower power output in the 2-minute test after the high-intensity session compared to both control (−8%) and moderate-intensity sessions (−7%). No significant differences in power output for the 5-minute and 12-minute tests between conditions. The high-intensity session also led to significantly lower W' values compared to both control (−27%) and moderate-intensity sessions (−26%), with no differences for CP.
PRACTICAL TAKEAWAY
The results of this study show that high intensity sessions can have a significant impact on subsequent training and performance. This suggests that these sorts of sessions should be more heavily weighted in training load metrics and should be given adequate time to recover from. My recommendation for athletes is to review their training logs to determine how quickly they are able to recover from hard sessions. They may need more than one or two days after a high intensity session and this information should be used for planning future training.
RELATED RESEARCH
Training load and acute performance decrements following different training sessions
The quantification of training load, the training response and the effect on performance
TRAINING: Long-term development of performance, physiological, and training characteristics in a world-class female biathlete
I enjoy reading research that looks at the training and performance of elite athletes. These sorts of studies are perhaps more difficult to rely on as they typically only consider one individual, but they do provide insight and inspiration for training that has been effective. In this study, the authors set out “to investigate the long-term development of performance, physiological, and training characteristics in a world-class female biathlete”.
STUDY DETAILS
The participant, a renowned female biathlete with 22 international championship medals and 28 World Cup wins, was studied from ages 17 to 33.
Training data included annual physical training volumes (409–792h per season) and shots fired (1,163–17,328 shots per season), with peak training at age 28 and a slight reduction at ages 31–33.
Maximal oxygen uptake in roller ski skating increased by 10% (62.9–69.2mlkg/min) from ages 22 to 27.
As a senior, the athlete's training volume was 48% higher (694h vs. 468h per season) and included 175% more shots fired (14,537 shots vs. 5,295 shots per season) compared to her junior years.
Senior training involved more low-intensity (602h vs. 392h) and moderate-intensity training (34h vs. 7h), with less high-intensity training (27h vs. 42h), and a significant increase in shooting practice, especially at rest and during low-intensity training.
PRACTICAL TAKEAWAY
This study provides some interesting insights into elite training. The gradual shift towards more training at a lower intensity later in her career while also focusing on more skill development during this time is particularly useful for long-term planning for athletes. I was surprised that the volume of high-intensity training was both relatively and absolutely lower during the later parts of her career she increased total training volume. My recommendation for athletes is to understand that training will evolve over their career and they should not chase sessions or targets from years ago, but rather focus on what they need as they develop and what they can cope with at different points in time.
RELATED RESEARCH
NUTRITION: Carbohydrate does not augment exercise-induced protein accretion versus protein alone
Protein ingestion to support muscle protein synthesis after training is well supported. Many recovery drinks also include carbohydrates which are intended to restore muscle glycogen, but these carbohydrates are sometimes also considered to help the muscle protein synthesis process. In this study, the authors set out to test “the thesis that CHO and protein coingestion would augment muscle protein synthesis (MPS) and inhibit muscle protein breakdown (MPB) at rest and after resistance exercise”.
STUDY DETAILS
Nine men (age=23.0±1.9 yr, BMI=24.2±2.1 kg·m) performed two knee extension trials, consuming either 25g whey protein (PRO) or 25g whey protein with 50g maltodextrin (PRO+CARB).
Muscle biopsies and stable isotope methodology measured MPS and MPB.
Glucose and insulin responses were significantly greater for PRO+CARB than PRO (17.5-fold and 5-fold increases, respectively).
Exercise increased MPS and MPB, but no differences were observed between PRO and PRO+CARB in both rested and exercised legs.
Phosphorylation of Akt was higher in the PRO+CARB trial and increased post-exercise for both trials.
PRACTICAL TAKEAWAY
The results of this study showed that coingesting carbohydrates with protein does not enhance muscle protein synthesis or inhibit muscle protein breakdown more than protein alone. My recommendation for athletes is to consider taking a protein only recovery drink after resistance training and a recovery drink with both protein and carbohydrates after hard endurance training sessions (to restore glycogen and not for protein synthesis purposes).
RELATED RESEARCH
PSYCHOLOGY: Less is more - Cyclists-triathletes’ 30 min cycling time-trial performance is impaired with multiple feedback compared to a single feedback
Deciding what data to use when training and racing and what feedback to incorporate into pacing is often taken for granted by athletes with watches and bike computers showing more and more data points. In this study, the authors set out “to compare different modes of feedback on cycling performance and investigate information acquisition in cyclists-triathletes”.
STUDY DETAILS
20 participants (10 non-cyclists, 10 cyclists-triathletes) completed two 30-minute self-paced cycling time trials, spaced 5-7 days apart.
Participants received either single feedback (elapsed time) or multiple feedback (power output, elapsed distance, elapsed time, cadence, speed, and heart rate).
Cyclists-triathletes' information acquisition was monitored using an eye tracker during the multiple feedback trial.
Perceptual measures of task motivation, ratings of perceived exertion (RPE), and affect were collected every 5 minutes. Performance variables and heart rate were recorded continuously.
Cyclists-triathletes showed higher average power output compared to non-cyclists with both feedback types. However, cyclists-triathletes' performance was impaired with multiple feedback, while non-cyclists' performance remained unaffected by feedback type.
PRACTICAL TAKEAWAY
There appears to be a negative impact on performance of multiple feedback even though the cyclists did not have different levels of RPE or fatigue. In addition, the authors noted that as the duration increased, the cyclists used less feedback and looked at the feedback less. My recommendation is to choose the most important feedback for an athlete to manage their race and to try to reduce this to the least number of data points possible. This may also evolve during a race with less feedback necessary later in a race so athletes can consider having additional data pages with fewer metrics that they can switch to during the course of a race.
RELATED RESEARCH
Volitional running and tone counting: the impact of cognitive load on running over natural terrain
Three weeks of mental training changes physiological outcomes during a time trial to exhaustion
Quick summary from last week’s paid newsletter
Paid subscribers receive a newsletter every week and have full access to all newsletters listed in the archives (435 studies and practical takeaways). Last week, the newsletter covered studies on the following topics:
Self-talk and performance in gymnastics
Energy deficiency impairs resistance training gains in lean mass
Effects of 8-day oral taurine supplementation on thermoregulation
Is coffee a useful source of caffeine pre-exercise?
Supershoes reduce oxygen cost and cumulative tibial loading