A Carbohydrate Ingestion Intervention in an Elite Athlete Who Follows a Low-Carbohydrate High-Fat Diet

This case study documents the performance of an elite-level, exceptionally well-fat-adapted endurance athlete as he reintroduced carbohydrate (CHO) ingestion during high-intensity training. He had followed a strict low-CHO high-fat (LCHF) diet for 2 y, during which he ate approximately 80 g of CHO per day and trained and raced while ingesting only water. While following this diet, he earned numerous podium finishes in triathlons of various distances. However, he approached the authors to test whether CHO supplementation during exercise would further increase his high-intensity performance without affecting his fat adaptation. This 7-wk n = 1 investigation included a 4-wk habitual LCHF diet phase during which he drank only water during training and performance trials and a 3-wk habitual diet plus CHO ingestion phase (LCHF + CHO) during which he followed his usual LCHF diet but ingested 60 g/h CHO during 8 high-intensity training sessions and performance trials. After each phase, rates of fat oxidation and 30-s sprint, 4-min sprint, 20-km time trial (TT), and 100-km TT performances were measured. Compared with LCHF, 20-km TT time improved by 2.8% after LCHF + CHO, which would be a large difference in competition. There was no change in 30-s sprint power, a small improvement in 4-min sprint power (1.6%), and a small reduction in 100-km TT time (1.1%). The authors conclude that CHO ingestion during exercise was likely beneficial for this fat-adapted athlete during high-intensity endurance-type exercise (4–30 min) but likely did not benefit his short-sprint or prolonged endurance performance.

Download Full-text

Extremely short duration high-intensity training substantially improves endurance performance in triathletes

Applied Physiology Nutrition and Metabolism ◽

10.1139/h2012-083 ◽

2012 ◽

Vol 37 (5) ◽

pp. 976-981 ◽

Cited By ~ 20

Author(s):

John Jakeman ◽

Simon Adamson ◽

John Babraj

Keyword(s):

Blood Lactate ◽

Short Duration ◽

High Intensity ◽

Lactate Concentration ◽

Time Trial ◽

Aerobic Performance ◽

Time To Exhaustion ◽

High Intensity Training ◽

Effective Training ◽

Intensity Training

High-intensity training (HIT) involving 30-s sprints is an effective training regimen to improve aerobic performance. We tested whether 6-s HITs can improve aerobic performance in triathletes. Six subelite triathletes (age, 40 ± 9 years; weight, 86 ± 11 kg; body mass index, 26 ± 3 kg·m–2) took part in cycle HIT and 6 endurance-trained subelite athletes (age, 36 ± 9 years; weight, 82 ± 11 kg; BMI, 26 ± 3 kg·m–2) maintained their normal training routine. Before and after 2 weeks of HIT, involving 10 × 6-s sprints or normal activity, participants performed a self-paced 10-km time trial and a time to exhaustion test on a cycle ergometer. Finger prick blood samples were taken throughout the time to exhaustion test to determine blood lactate concentration. Two weeks of HIT resulted in a 10% decrease in self-paced 10-km time trial (p = 0.03) but no significant change in time to exhaustion. The time taken to reach onset of blood lactate accumulation (OBLA, defined as the point where blood lactate reaches 4 mmol·L–1) was significantly increased following 2 weeks of HIT (p = 0.003). The change in time trial performance was correlated to the change in time taken to reach OBLA (R2 = 0.63; p = 0.001). We concluded that a very short duration HIT is a very effective training regimen to improve aerobic performance in subelite triathletes and this is associated with a delay in blood lactate build-up.

Download Full-text

High-Intensity Interval Training and Sprint-Interval Training in National-Level Rowers

Frontiers in Physiology ◽

10.3389/fphys.2021.803430 ◽

2021 ◽

Vol 12 ◽

Author(s):

Kirstie Jodie Turner ◽

David Bruce Pyne ◽

Julien D. Périard ◽

Anthony John Rice

Keyword(s):

High Intensity ◽

National Level ◽

Time Trial ◽

Interval Training ◽

Training Methods ◽

Incremental Test ◽

High Intensity Training ◽

Significant Difference ◽

High Intensity Interval ◽

Intensity Training

Purpose: The effects of two different high-intensity training methods on 2,000 m rowing ergometer performance were examined in a feasibility study of 24 national-level rowers aged 18–27 years (17 males, 2,000 m ergometer time trial 6:21.7 ± 0:14.6 (min:s) and seven females, 2,000 m ergometer 7:20.3 ± 0:12.1. Habitual training for all participants was ~12–16 h per week).Methods: 16 high-intensity ergometer sessions were completed across two 3-week periods. Participants were allocated into two groups according to baseline 2,000 m time. High-intensity interval session-sprint-interval session (HIIT-SIT) completed eight HIIT (8 × 2.5 min intervals; 95% of 2,000 m wattage) followed by eight SIT (three sets of 7 × 30 s intervals; maximum effort). SIT-HIIT completed eight SIT sessions followed by eight HIIT sessions. Both a 2,000-m time trial and a progressive incremental test finishing with 4 min “all-out” performance were completed before and after each 3-week phase.Results: Both groups showed similar improvements in 2,000 m time and 4 min “all-out” distance after the first 3 weeks (2,000 m time: HIIT-SIT: −2.0 ± 0.6%, mean ± 90% CL, p = 0.01; SIT-HIIT: −1.5 ± 0.3%, p = 0.01) with no significant difference between groups. HIIT-SIT demonstrated the greatest improvements in submaximal heart rate (HR) during the progressive incremental test with eight sessions of HIIT showing a greater reduction in submaximal HR than eight sessions of SIT. The net improvement of 16 high-intensity sessions on 2,000 m time was −2.5% for HIIT-SIT (−10.6 ± 3.9 s, p = 0.01) and − 2.2% for SIT-HIIT (−9.0 ± 5.7 s, p = 0.01) and for 4 min “all-out” performance was 3.1% for HIIT-SIT (36 ± 25 m, p = 0.01) and 2.8% for SIT-HIIT (33 ± 27 m, p = 0.01).Conclusion: Eight sessions of high-intensity training can improve 2,000 m ergometer rowing performance in national-level rowers, with a further eight sessions producing minimal additional improvement. The method of high-intensity training appears less important than the dose.

Download Full-text

Effects of Increased Load of Low- Versus High-Intensity Endurance Training on Performance and Physiological Adaptations in Endurance Athletes

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2021-0190 ◽

2021 ◽

pp. 1-10

Author(s):

Rune K. Talsnes ◽

Roland van den Tillaar ◽

Øyvind Sandbakk

Keyword(s):

Oxygen Uptake ◽

Endurance Training ◽

Maximal Oxygen Uptake ◽

High Intensity ◽

Time Trial ◽

Endurance Athletes ◽

High Intensity Training ◽

Low Intensity ◽

Physiological Adaptations ◽

Intensity Training

Purpose: To compare the effects of increased load of low- versus high-intensity endurance training on performance and physiological adaptations in well-trained endurance athletes. Methods: Following an 8-week preintervention period, 51 (36 men and 15 women) junior cross-country skiers and biathletes were randomly allocated into a low-intensity (LIG, n = 26) or high-intensity training group (HIG, n = 25) for an 8-week intervention period, load balanced using the overall training impulse score. Both groups performed an uphill running time trial and were assessed for laboratory performance and physiological profiling in treadmill running and roller-ski skating preintervention and postintervention. Results: Preintervention to postintervention changes in running time trial did not differ between groups (P = .44), with significant improvements in HIG (−2.3% [3.2%], P = .01) but not in LIG (−1.5% [2.9%], P = .20). There were no differences between groups in peak speed changes when incremental running and roller-ski skating to exhaustion (P = .30 and P = .20, respectively), with both modes being significantly improved in HIG (2.2% [3.1%] and 2.5% [3.4%], both P < .01) and in roller-ski skating for LIG (1.5% [2.4%], P < .01). There was a between-group difference in running maximal oxygen uptake changes (P = .04), tending to improve in HIG (3.0% [6.4%], P = .09) but not in LIG (−0.7% [4.6%], P = .25). Changes in roller-ski skating peak oxygen uptake differed between groups (P = .02), with significant improvements in HIG (3.6% [5.4%], P = .01) but not in LIG (−0.1% [0.17%], P = .62). Conclusion: There was no significant difference in performance adaptations between increased load of low- versus high-intensity training in well-trained endurance athletes, although both methods improved performance. However, increased load of high-intensity training elicited better maximal oxygen uptake adaptations compared to increased load of low-intensity training.

Download Full-text

“Living high-training low” altitude training improves sea level performance in male and female elite runners

Journal of Applied Physiology ◽

10.1152/jappl.2001.91.3.1113 ◽

2001 ◽

Vol 91 (3) ◽

pp. 1113-1120 ◽

Cited By ~ 190

Author(s):

James Stray-Gundersen ◽

Robert F. Chapman ◽

Benjamin D. Levine

Keyword(s):

Sea Level ◽

Oxygen Transport ◽

High Intensity ◽

Endurance Performance ◽

Altitude Training ◽

Moderate Altitude ◽

High Intensity Training ◽

Low Altitude ◽

Intensity Training ◽

Elite Runners

Acclimatization to moderate high altitude accompanied by training at low altitude (living high-training low) has been shown to improve sea level endurance performance in accomplished, but not elite, runners. Whether elite athletes, who may be closer to the maximal structural and functional adaptive capacity of the respiratory (i.e., oxygen transport from environment to mitochondria) system, may achieve similar performance gains is unclear. To answer this question, we studied 14 elite men and 8 elite women before and after 27 days of living at 2,500 m while performing high-intensity training at 1,250 m. The altitude sojourn began 1 wk after the USA Track and Field National Championships, when the athletes were close to their season's fitness peak. Sea level 3,000-m time trial performance was significantly improved by 1.1% (95% confidence limits 0.3–1.9%). One-third of the athletes achieved personal best times for the distance after the altitude training camp. The improvement in running performance was accompanied by a 3% improvement in maximal oxygen uptake (72.1 ± 1.5 to 74.4 ± 1.5 ml · kg−1· min−1). Circulating erythropoietin levels were near double initial sea level values 20 h after ascent (8.5 ± 0.5 to 16.2 ± 1.0 IU/ml). Soluble transferrin receptor levels were significantly elevated on the 19th day at altitude, confirming a stimulation of erythropoiesis (2.1 ± 0.7 to 2.5 ± 0.6 μg/ml). Hb concentration measured at sea level increased 1 g/dl over the course of the camp (13.3 ± 0.2 to 14.3 ± 0.2 g/dl). We conclude that 4 wk of acclimatization to moderate altitude, accompanied by high-intensity training at low altitude, improves sea level endurance performance even in elite runners. Both the mechanism and magnitude of the effect appear similar to that observed in less accomplished runners, even for athletes who may have achieved near maximal oxygen transport capacity for humans.

Download Full-text

Standardized Versus Customized High-Intensity Training: Effects on Cycling Performance

International Journal of Sports Physiology and Performance ◽

10.1123/ijspp.2012-0389 ◽

2014 ◽

Vol 9 (2) ◽

pp. 292-301 ◽

Cited By ~ 12

Author(s):

Benoit Capostagno ◽

Michael I. Lambert ◽

Robert P. Lamberts

Keyword(s):

High Intensity ◽

Heart Rate Recovery ◽

Time Trial ◽

Interval Training ◽

Training Group ◽

Cycling Performance ◽

High Intensity Interval Training ◽

High Intensity Training ◽

High Intensity Interval ◽

Intensity Training

Purpose:To determine whether a submaximal cycling test could be used to monitor and prescribe high-intensity interval training (HIT).Methods:Two groups of male cyclists completed 4 HIT sessions over a 2-wk period. The structured-training group (SG; n = 8, VO2max = 58.4 ± 4.2 mL · min−1 · kg−1) followed a predetermined training program while the flexible-training group (FG; n = 7, VO2max = 53.9 ± 5.0 mL · min−1 · kg−1) had the timing of their HIT sessions prescribed based on the data of the Lamberts and Lambert Submaximal Cycle Test (LSCT).Results:Effect-size calculations showed large differences in the improvements in 40-km time-trial performance after the HIT training between SG (8 ± 45 s) and FG (48 ± 42 s). Heart-rate recovery, monitored during the study, tended to increase in FG and remain unchanged in SG.Conclusions:The results of the current study suggest that the LSCT may be a useful tool for coaches to monitor and prescribe HIT.

Download Full-text