diff --git a/backend/src/routes/exercises.js b/backend/src/routes/exercises.js
new file mode 100644
index 0000000..73e0866
--- /dev/null
+++ b/backend/src/routes/exercises.js
@@ -0,0 +1,173 @@
+const express = require('express');
+const pool = require('../db/pool');
+const router = express.Router();
+
+// Validation helper
+const validateExercise = (data) => {
+  const errors = [];
+  if (!data.name || typeof data.name !== 'string' || !data.name.trim()) {
+    errors.push('name is required and must be non-empty');
+  }
+  if (data.difficulty && !['beginner', 'intermediate', 'advanced'].includes(data.difficulty)) {
+    errors.push('difficulty must be beginner, intermediate, or advanced');
+  }
+  if (data.muscle_groups && !Array.isArray(data.muscle_groups)) {
+    errors.push('muscle_groups must be an array');
+  }
+  if (data.equipment_needed && !Array.isArray(data.equipment_needed)) {
+    errors.push('equipment_needed must be an array');
+  }
+  return errors;
+};
+
+// CREATE - Add new exercise
+router.post('/', async (req, res) => {
+  try {
+    const { name, description, instructions, muscle_groups, difficulty, equipment_needed, video_url, created_by } = req.body;
+    
+    const errors = validateExercise({ name, difficulty, muscle_groups, equipment_needed });
+    if (errors.length > 0) {
+      return res.status(400).json({ error: 'Validation failed', details: errors });
+    }
+
+    const query = `
+      INSERT INTO exercises (name, description, instructions, muscle_groups, difficulty, equipment_needed, video_url, created_by)
+      VALUES ($1, $2, $3, $4, $5, $6, $7, $8)
+      RETURNING *
+    `;
+    
+    const result = await pool.query(query, [
+      name.trim(),
+      description || null,
+      instructions || null,
+      muscle_groups || [],
+      difficulty || 'intermediate',
+      equipment_needed || [],
+      video_url || null,
+      created_by || 'system'
+    ]);
+
+    res.status(201).json(result.rows[0]);
+  } catch (err) {
+    if (err.code === '23505') {
+      return res.status(409).json({ error: 'Exercise name already exists' });
+    }
+    console.error('Error creating exercise:', err);
+    res.status(500).json({ error: 'Failed to create exercise' });
+  }
+});
+
+// READ - Get all exercises with search/filter
+router.get('/', async (req, res) => {
+  try {
+    const { search, difficulty, muscle_group, limit = 50, offset = 0 } = req.query;
+    
+    let query = 'SELECT * FROM exercises WHERE 1=1';
+    const params = [];
+    let paramCount = 1;
+
+    if (search) {
+      query += ` AND (name ILIKE $${paramCount} OR description ILIKE $${paramCount})`;
+      params.push(`%${search}%`);
+      paramCount++;
+    }
+
+    if (difficulty) {
+      query += ` AND difficulty = $${paramCount}`;
+      params.push(difficulty);
+      paramCount++;
+    }
+
+    if (muscle_group) {
+      query += ` AND $${paramCount} = ANY(muscle_groups)`;
+      params.push(muscle_group);
+      paramCount++;
+    }
+
+    query += ` ORDER BY name ASC LIMIT $${paramCount} OFFSET $${paramCount + 1}`;
+    params.push(parseInt(limit), parseInt(offset));
+
+    const result = await pool.query(query, params);
+    res.json(result.rows);
+  } catch (err) {
+    console.error('Error fetching exercises:', err);
+    res.status(500).json({ error: 'Failed to fetch exercises' });
+  }
+});
+
+// READ - Get single exercise
+router.get('/:id', async (req, res) => {
+  try {
+    const result = await pool.query('SELECT * FROM exercises WHERE id = $1', [req.params.id]);
+    
+    if (result.rows.length === 0) {
+      return res.status(404).json({ error: 'Exercise not found' });
+    }
+
+    res.json(result.rows[0]);
+  } catch (err) {
+    console.error('Error fetching exercise:', err);
+    res.status(500).json({ error: 'Failed to fetch exercise' });
+  }
+});
+
+// UPDATE - Modify exercise
+router.put('/:id', async (req, res) => {
+  try {
+    const { name, description, instructions, muscle_groups, difficulty, equipment_needed, video_url } = req.body;
+    
+    const errors = validateExercise({ name, difficulty, muscle_groups, equipment_needed });
+    if (errors.length > 0) {
+      return res.status(400).json({ error: 'Validation failed', details: errors });
+    }
+
+    const query = `
+      UPDATE exercises 
+      SET name = $1, description = $2, instructions = $3, muscle_groups = $4, 
+          difficulty = $5, equipment_needed = $6, video_url = $7, updated_at = CURRENT_TIMESTAMP
+      WHERE id = $8
+      RETURNING *
+    `;
+
+    const result = await pool.query(query, [
+      name.trim(),
+      description || null,
+      instructions || null,
+      muscle_groups || [],
+      difficulty || 'intermediate',
+      equipment_needed || [],
+      video_url || null,
+      req.params.id
+    ]);
+
+    if (result.rows.length === 0) {
+      return res.status(404).json({ error: 'Exercise not found' });
+    }
+
+    res.json(result.rows[0]);
+  } catch (err) {
+    if (err.code === '23505') {
+      return res.status(409).json({ error: 'Exercise name already exists' });
+    }
+    console.error('Error updating exercise:', err);
+    res.status(500).json({ error: 'Failed to update exercise' });
+  }
+});
+
+// DELETE - Remove exercise
+router.delete('/:id', async (req, res) => {
+  try {
+    const result = await pool.query('DELETE FROM exercises WHERE id = $1 RETURNING *', [req.params.id]);
+
+    if (result.rows.length === 0) {
+      return res.status(404).json({ error: 'Exercise not found' });
+    }
+
+    res.json({ message: 'Exercise deleted', id: req.params.id });
+  } catch (err) {
+    console.error('Error deleting exercise:', err);
+    res.status(500).json({ error: 'Failed to delete exercise' });
+  }
+});
+
+module.exports = router;
diff --git a/db/migrations/005_create_exercises_table.sql b/db/migrations/005_create_exercises_table.sql
new file mode 100644
index 0000000..d2995f9
--- /dev/null
+++ b/db/migrations/005_create_exercises_table.sql
@@ -0,0 +1,18 @@
+-- Create exercises table for exercise encyclopedia
+CREATE TABLE IF NOT EXISTS exercises (
+  id SERIAL PRIMARY KEY,
+  name VARCHAR(255) NOT NULL UNIQUE,
+  description TEXT,
+  instructions TEXT,
+  muscle_groups TEXT[] DEFAULT ARRAY[]::text[],
+  difficulty VARCHAR(20) DEFAULT 'intermediate' CHECK (difficulty IN ('beginner', 'intermediate', 'advanced')),
+  equipment_needed TEXT[] DEFAULT ARRAY[]::text[],
+  video_url VARCHAR(255),
+  created_by VARCHAR(50),
+  created_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP,
+  updated_at TIMESTAMP DEFAULT CURRENT_TIMESTAMP
+);
+
+CREATE INDEX idx_exercises_name ON exercises(name);
+CREATE INDEX idx_exercises_difficulty ON exercises(difficulty);
+CREATE INDEX idx_exercises_muscle_groups ON exercises USING GIN(muscle_groups);