Can Ischemic Intra-Conditioning (IIC) improve 30m sprint performance?

🔦The concept of Ischemia as a performance enhancer is definitely not novel. Thus, recently a group of researchers from the University of Gdansk, Katowice, Prague, and New York have explored if IIC can improve repeated 30m sprint times.

📖Introduction: There are four primary methods of applying BFR during exercise: Ischemic Pre-Conditioning (IPC), continuous, intermittent, and as explored in the present study IIC.

From previous data and research, it seems that BFR can increase maximal oxygen uptake in trained individuals and BFR can easily be applied during various types of exercise, including walking, cycling, running and even sprinting.

In previous research, Ischemic BFR sprint training seems to decrease muscle damage and increase muscle mass. However, frequent BFR applied in the same area can mechanically impair muscle structure with risks of contusion type of muscle damage. BFR applied during sports activities may also negatively impact sport-specific techniques, and it is not known whether submaximal or maximal sprinting with BFR affects movement technique, rhythm, or stride length.

To address these potential risks and negative consequences, the authors found that BFR during rest periods/IIC may be more appropriate.

IIC has previously been explored, and it seems to increase power output and mitigate exercise fatigue but has primarily been studied in combination with resistance training. Thus, Behringer et al. demonstrated the positive adaptations to sprint training with concurrent BFR, in 6 x 100m sprints at 60-70% of their maximum 100m pace.

Despite the potential benefits of IIC for improving sprint performance, no research to date has examined the effects of BFR applied in the inter-set rest periods only.

The authors hypothesised that the application of ICC can improve sprint performance during successive 30m trials.

Aim:
To investigate the impact of IIC applied during rest intervals on 30m sprint performance.

Methods:
Crossover, randomized design.

Inclusion criteria and Participants: Minimum of 3 years of professional sports training with a minimum of 3 training sessions per week. Thirty-four male (n = 12) and female (n = 22) track and field sprinters, jumpers, and rugby players. One week before the main experiment, the participants performed a familiarization session as a general warm-up and followed by 3 trials of 30-meter sprints with BFR at 60% AOP. The experimental session was performed one week apart:

A. (IIC 60% AOP) BFR at 60% Arterial Occlusion Pressure (AOP) assessed with a handheld Doppler
B. (IIC 80% AOP) BFR applied at 80% AOP
C. control, no ischemia applied

Training: During each session, participants performed 6 x 30m sprints with 7 min inter-set rest.

In groups a and b, 10 cm-wide contoured cuffs (Fit Cuffs V3) were applied and inflated bilaterally to the most proximal region of the thigh before the sprint and during the inter-set rest intervals.

For the IIC groups the cuffs were applied and inflated 1 min after each interval for 5 min, with 1 min reperfusion before the following interval. (1 min passive rest + 5 min BFR + 1 min reperfusion/passive rest). Completion time was measured independently for each sprint.

Results:
No statistically significant difference between the 3 groups. There was also no main effect in delta values of BFR for any condition.

Discussion:
Despite no change in sprint time during the 6 trials, IIC did not negatively impact performance in consecutive sprints either.

This study proposes that inter-set IIC, although not increasing efficiency acutely might enhance long term physiological responses through increased metabolic stress, muscle fiber recruitment, and improved intramuscular signaling for protein synthesis—without impacting sprint training efficiency. It’s worth noting that BFR applied during exercise may lead to increased muscle pain and exertion, which can limit its use among elite athletes due to their heightened perceptual demands.

Further research should examine the effects of inter-set BFR / IIC, compare different training protocols and types of exercise, as well as the duration of IIC.

Conclusion: This IIC protocols did not enhance the performance of 30 m sprints performed by athletes. Though no improvement in 30m sprint performance was detected with IIC, the intervention did neither mitigate the decline in performance compared to the control group. Because of this, it can be speculated that training protocols with IIC may augment chronic muscle adaptations to sprinting. This suggests that IIC may help maintain or improve sprint performance in the long term, thus the effect cannot be detected acutely.

Proposals for revised protocols to attain acute effects of ICC and future avenues:
It can be speculated, that near 100% AOP and possible also addional ischemic- and reperfusion intervals are needed to detect any acute effect of IIC on running performance.

Maybe the dosage of sprints is of importance. As 6 sprints intersected by 7 min rest, in itself might be sufficient time for a full restitution regardless of IIC. Following this line of thought, it can be hypothesized that if the protocol consisted of more intervals and shorter inter-set rest periods, IIC might be superior to passive rest.

Worth noting is the questionable extrapolative value of IIC on sprinting performance, as in most team sports and most athletic disciplines this is not applicable. Though, if optimized IIC protocols have acute performance improvements, athletes could use IIC in the breaks between sets, rounds, or in sports with running substitutions.

Lastly, the potential of IIC to optimize long-term restitution with relevance for the performance of consecutive training bouts?

Primary Source:
Krzysztof Fostiak, Marta Bichowska, Robert Trybulski, Bartosz Trabka, Michal Krzysztofik, Nicholas Rolnick, Aleksandra Filip-Stachnik and Michal Wilk (2022) Acute Effects of Ischemic Intra-Conditioning on 30 m Sprint Performance

Secondary Source:
Wilk et al. (2021) Impact of Ischemic Intra-Conditioning on Power Output and Bar Velocity of the Upper Limbs
Kaijser et al. (1990) Muscle oxidative capacity and work performance after training under local leg ischemia
Barbosa et al. (2014) Remote ischemic preconditioning delays fatigue development during handgrip exercise
Groot et al. (2010) Ischemic preconditioning improves maximal performance in humans
Behringer et al. (2017) Low-Intensity Sprint Training with Blood Flow Restriction Improves 100-m Dash