Chronic Effects of the Use of Instep Weights on Specific Capacities in Soccer Players

Chronic Effects of the Use of Instep Weights on Technical, Physical and Perceptual Parameters in Young Male Soccer Players

The main goal of this randomized controlled trial (RCT) is to evaluate the chronic effects of using instep weights on technical, physical (conditional), and perceptual parameters in amateur male soccer players.

The secondary objective will be to propose a training methodology using instep weights to enhance athletic performance.

The following hypotheses are formulated based on the objectives outlined previously.

Hypothesis 1: the use of instep weights will enhance performance in ball striking speed, change of direction ability, and repeated sprint capacity.

Hypothesis 2: the use of instep weights will negatively affect performance in ball striking accuracy and ball control.

Hypothesis 3: the use of instep weights will not produce adverse effects on perceived exertion, groin pain or reduce maximal adductor, quadriceps and hamstring muscle contraction values.

A RCT will be performed and players will be randomly assigned in one of the two groups (experimental or control).

Players will attend their regular training sessions and the protocol will be divided into two phases:

• Phase 1: familiarization On the recruitment day, players will be briefed on the study procedures, followed by the reading and signing of informed consent forms. Familiarization with the study procedures will take place over the two weeks prior to the intervention phase. During this period, participants will practice all testing protocols once a week and will wear 100-gram instep weights in different training sessions.
• Phase 2: intervention During the intervention phase, all players who meet the inclusion and exclusion criteria will be recruited and will be randomly allocated into an intervention group (experimental) or a non-intervention group (control group). Randomization will be conducted by an external researcher using blocked randomization via a web-based tool (Urbinak, 1997). Both groups will undergo distinct interventions over an 8-week period.

The study will be conducted during the competitive season on artificial turf field under consistent environmental conditions. Players will wear soccer boots for all testing procedures. Testing will occur at three time points:

• Pre-intervention: first day of Week 1 to collect baseline data.
• Mid-intervention: first day of Week 5.
• Post-intervention: first day of Week 9.

Inclusion Criteria:

• amateur young male soccer player (under federation regulation)
• minimum three years of experience playing soccer
• train 3 days/week and 5 hours/week (minimum)

Exclusion Criteria:

• Injured players
• Goalkeepers
• Players unable to perform at their best
• Players that will miss more than two training sessions
• Players under medication or using performance enhancement supplements
• Players under 16 years old